Sponsors
Thứ Năm, 29 tháng 8, 2013
CRM Blog World Updated
One of the most viewed pages on my blog is still the Blog World. When Dynamics CRM wasn't called Dynamics CRM yet, I have started to gather a list of blogs which targeted this software. Over the years this list has grown and I have just updated the list with the blogs which I have been requested to add. I guess soon I'll need to do a full review of this list as I've noticed that some people have
Thứ Năm, 8 tháng 8, 2013
Project Euler
I came across the Project Euler site the other day. If you enjoy solving mathematical/programming problems then I recommend this site. You're given a number of problems to solve with each problem in the series getting progressively more difficult. If you sign up, you can submit your answer and if your answer is correct then you'll get access to the message boards for the problem you worked on. The problem message boards are where you can share your solution and see solutions by other people who may have used a different programming language. It's interesting to see the C# solutions compared to the solutions in other languages. Worth a look if you have time!
Chủ Nhật, 28 tháng 7, 2013
Implicit/Explicit Conversion Operators
I saw some code yesterday which at first glance looked odd. A method was accepting a parameter of a custom type named Money and the calling code was passing in a double value. After a bit of confusion I recalled that the C# language natively supports conversion operators.
If you have a custom type, you have the option to define conversion operators on your type which let you convert from your custom type to a target type and from the target type back to the custom type. Conversion can be implicit or explicit. Implicit conversion means that users of your custom type can convert to the target type without having to perform a type cast operation. Explicit conversion forces a type cast to be performed.
To demonstrate this, we'll use the case I came across. Imagine we have a Money class which is composed of a currency and a value that the money represents. We may initially decide that we want the Money class to be flexible so that users of the class can treat it is a value (a double type in this case). This means that when a double is expected (e.g. as an argument to a method), the user of the class can pass the Money instance which will implicitly be converted to its value form. Moreover, we can also make the conversion from double to Money implicit, meaning that whenever a Money instance is expected, we can pass in a double. Our initial attempt at the Money class implementation would therefore look something like:
Cannot implicitly convert type 'ConversionOperators.Money' to 'double'. An explicit conversion exists (are you missing a cast?)
Cannot implicitly convert type 'double' to 'ConversionOperators.Money'. An explicit conversion exists (are you missing a cast?)
As the errors point out, we now need to explicitly cast between the types - as demonstrated in the code below.
You can download the example code by clicking here.
If you have a custom type, you have the option to define conversion operators on your type which let you convert from your custom type to a target type and from the target type back to the custom type. Conversion can be implicit or explicit. Implicit conversion means that users of your custom type can convert to the target type without having to perform a type cast operation. Explicit conversion forces a type cast to be performed.
To demonstrate this, we'll use the case I came across. Imagine we have a Money class which is composed of a currency and a value that the money represents. We may initially decide that we want the Money class to be flexible so that users of the class can treat it is a value (a double type in this case). This means that when a double is expected (e.g. as an argument to a method), the user of the class can pass the Money instance which will implicitly be converted to its value form. Moreover, we can also make the conversion from double to Money implicit, meaning that whenever a Money instance is expected, we can pass in a double. Our initial attempt at the Money class implementation would therefore look something like:
public class Money
{
public string Currency { get; set; }
public double Value { get; set; }
// Implicit conversion from Money to double
public static implicit operator double(Money money)
{
return money.Value;
}
// Implicit conversion from double to Money
public static implicit operator Money(double @double)
{
return new Money { Value = @double };
}
}
With the above class, the following code would therefore compile: {
public string Currency { get; set; }
public double Value { get; set; }
// Implicit conversion from Money to double
public static implicit operator double(Money money)
{
return money.Value;
}
// Implicit conversion from double to Money
public static implicit operator Money(double @double)
{
return new Money { Value = @double };
}
}
var money = new Money() { Currency = "GBP", Value = 10.5 };
// Implicitly convert Money to a double
double moneyValue = money;
// Convert a double to Money (Money.Currency will be null!)
Money moneyInstance = moneyValue;
Notice that when converting a Money instance to a double, we would lose information on the Money instance (the currency in this case). Also, when converting a double to a Money, the currency is never set. It would therefore make more sense in this scenario to use explicit conversion operators so that the user is forced to be aware that they could lose information in the conversion or have a partially initialised Money instance (it isn't a straight-forward conversion). To define explicit conversion on the Money class, the only change required would be to replace the "implicit" keyword with the "explicit" keyword on the two conversion methods. The Money class would now look like: // Implicitly convert Money to a double
double moneyValue = money;
// Convert a double to Money (Money.Currency will be null!)
Money moneyInstance = moneyValue;
public class Money
{
public string Currency { get; set; }
public double Value { get; set; }
// Explicit conversion from Money to double
public static explicit operator double(Money money)
{
return money.Value;
}
// Explicit conversion from double to Money
public static explicit operator Money(double @double)
{
return new Money { Value = @double };
}
}
After making this change, the example calling code above would fail to compile with the following two compile-time error messages: {
public string Currency { get; set; }
public double Value { get; set; }
// Explicit conversion from Money to double
public static explicit operator double(Money money)
{
return money.Value;
}
// Explicit conversion from double to Money
public static explicit operator Money(double @double)
{
return new Money { Value = @double };
}
}
Cannot implicitly convert type 'ConversionOperators.Money' to 'double'. An explicit conversion exists (are you missing a cast?)
Cannot implicitly convert type 'double' to 'ConversionOperators.Money'. An explicit conversion exists (are you missing a cast?)
As the errors point out, we now need to explicitly cast between the types - as demonstrated in the code below.
var money = new Money() { Currency = "GBP", Value = 10.5 };
double moneyValue = (double) money;
Money moneyInstance = (Money) moneyValue;
double moneyValue = (double) money;
Money moneyInstance = (Money) moneyValue;
You can download the example code by clicking here.
Chủ Nhật, 7 tháng 7, 2013
JQuery DataTables Editable in Asp.net c#
Asp.Net How To Edit JQuery DataTables Using Asp.Net GridView , C#
The purpose of this article is to show how you can implement JQuery DataTables with Asp.net Gridview Control. The jQuery DataTables plugin is an excellent client-side component. This plugin adds lots of functionalities to the plain HTML tables that are placed in web pages such as sorting, searching, pagination, changing page length etcHTML Markup:
Here you will see in html markup theres a pencil image which on click becomes editable and so user can edit the values also look at classname .i.e set classname as update_ + id using string.Concat(). where id is database rowId.
<asp:GridView ID="myGridview" runat="server" BackColor="White" AutoGenerateColumns="False" CssClass="gvmyalign"
BorderColor="Gray" BorderStyle="Solid" BorderWidth="1px" CellPadding="4" ForeColor="Black" GridLines="None" Width="500px"
AllowPaging="True" ShowFooter="false" >
<SelectedRowStyle BackColor="#E2DED6" Font-Bold="True" ForeColor="#333333" />
<HeaderStyle BackColor="#A86E07" Font-Bold="True" ForeColor="White" />
<Columns>
<asp:TemplateField HeaderText="Id" Visible="false">
<ItemTemplate>
<asp:Label ID="lblid" runat="server" Text='<%# Eval("Id") %>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Name" ItemStyle-Width="230">
<ItemTemplate>
<asp:Label ID="lblname" runat="server" Text='<%# Eval("Name") %>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField ShowHeader="False" ItemStyle-Width="90" >
<ItemTemplate>
<asp:Image ID="Image1" ToolTip="Edit" style="cursor:pointer;" CssClass=' <%# string.Concat("update_",Eval("Id")) %>' ImageUrl="~/images/pencil.png" runat="server" />
</ItemTemplate>
</asp:TemplateField>
</Columns>
<PagerStyle BackColor="#A86E07" ForeColor="White" HorizontalAlign="Center" />
<EditRowStyle BackColor="#d9d9d9" />
<AlternatingRowStyle BackColor="White" ForeColor="#A86E07" />
</asp:GridView>
BorderColor="Gray" BorderStyle="Solid" BorderWidth="1px" CellPadding="4" ForeColor="Black" GridLines="None" Width="500px"
AllowPaging="True" ShowFooter="false" >
<SelectedRowStyle BackColor="#E2DED6" Font-Bold="True" ForeColor="#333333" />
<HeaderStyle BackColor="#A86E07" Font-Bold="True" ForeColor="White" />
<Columns>
<asp:TemplateField HeaderText="Id" Visible="false">
<ItemTemplate>
<asp:Label ID="lblid" runat="server" Text='<%# Eval("Id") %>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Name" ItemStyle-Width="230">
<ItemTemplate>
<asp:Label ID="lblname" runat="server" Text='<%# Eval("Name") %>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField ShowHeader="False" ItemStyle-Width="90" >
<ItemTemplate>
<asp:Image ID="Image1" ToolTip="Edit" style="cursor:pointer;" CssClass=' <%# string.Concat("update_",Eval("Id")) %>' ImageUrl="~/images/pencil.png" runat="server" />
</ItemTemplate>
</asp:TemplateField>
</Columns>
<PagerStyle BackColor="#A86E07" ForeColor="White" HorizontalAlign="Center" />
<EditRowStyle BackColor="#d9d9d9" />
<AlternatingRowStyle BackColor="White" ForeColor="#A86E07" />
</asp:GridView>
Code Behind: DefaultPage.aspx
You need to add Page_PreRender event on .cs where we set gridview's UseAccessibleHeader=true .
protected void (object sender, EventArgs e)
{
if (myGridview.Rows.Count > 0) {
myGridview.UseAccessibleHeader = true;
myGridview.HeaderRow.TableSection = TableRowSection.TableHeader;
}
}
protected void Page_Load(object sender, EventArgs e) {
if (!Page.IsPostBack) { gvBind(); }
}
public void gvBind() {
myGridview.EmptyDataText = "No Record";
DataTable dt = getData();
myGridview.DataSource = dt;
myGridview.DataBind();
}
Now the Real coding part comes here using JQuery Datatables .
Add JqueryDatable Script FilesNow after apply JQuery DataTable Gridview look like below image. ScreenShot:
<link href="jquery.dataTables_themeroller.css" rel="stylesheet" type="text/css" />
<script src="../js/jquery.dataTables.js" type="text/javascript"></script>
<script src="../js/jquery.dataTables.min.js" type="text/javascript"></script>
<script type="text/javascript">
$(document).ready(function () {
var oTable;
$(".gvmyalign span").contents().unwrap();
oTable = $(".gvmyalign").dataTable({
"bJQueryUI": true,
"sPaginationType": "full_numbers"
});
});
</script>
Now:
Client Side:
<script type="text/javascript">
var oTable;
function editRow(oTable, nRow) {
var aData = oTable.fnGetData(nRow);
var jqTds = $('>td', nRow);
var gtval = aData[1];
var absValue = $("#hdid").val();
var mySav_Class = absValue.replace('update_', 'sav_');
var myCnl_Class = absValue.replace('update_', 'cnl_');
var sname = $("#hdname").val();
jqTds[0].innerHTML = '<input class="edt1" type="text" value="' + sname + '">';
jqTds[1].innerHTML = '<img class="' + mySav_Class + '" title="Save" src="save.png" /><img class="' + myCnl_Class + '" title="Cancel" src="cancle.png" />';
}
function restoreRow(oTable, nRow) {
var aData = oTable.fnGetData(nRow);
var jqTds = $('>td', nRow);
for (var i = 0, iLen = jqTds.length; i < iLen; i++) {
oTable.fnUpdate(aData[i], nRow, i, false);
}
oTable.fnDraw();
}
function updatevalidDatarow() {
if ($('.edt1').val() == "") {
alert("Enter name.");
return false
}
return true;
}
$(document).ready(function () {
//One Pencil Img click make it editable mode
var nEditing = null;
$("img[class^='update_']").live('click', function (event) {
event.preventDefault;
var getId = $(this).attr("class");
$("#hdid").val(getId); // hdid is hidden field
var nRow = $(this).parents('tr')[0];
var setName = $.trim($(this).closest('tr').find('td').eq(0).text());
$("#hdname").val(setName); // hdname is hidden field
if (nEditing !== null && nEditing != nRow) {
restoreRow(oTable, nEditing);
editRow(oTable, nRow);
nEditing = nRow;
}
else {
editRow(oTable, nRow);
nEditing = nRow;
}
});
//On cancle Img click undo editable mode ie not editable
$("img[class^='cnl_']").live('click', function (event) {
var abc = $(this).attr("class");
var datetxt = $("#hdname").val();
$('.edt1').replaceWith(datetxt);
var arr = [];
arr = abc.split('_');
var id = arr[1];
var updateclass = "update_" + id;
var updatebtn = '<img src="pencil.png" style="cursor:pointer;" title="Edit" class="' + updateclass + '">';
$('.' + abc).replaceWith(updatebtn);
$('.sav_' + id).replaceWith("");
});
//On save Img Click update Query fire and saves the record into database.
$("img[class^='sav_']").live('click', function (event) {
var s = $(this).attr('class');
var arr = [];
arr = s.split('_');
var id = arr[1];
var updateclass = "update_" + id;
var updatebtn = '<img src="pencil.png" title="Edit" style="cursor:pointer;" class="' + updateclass + '">';
var upName = $(".edt1").val();
var dataString = id+"="+upName;
var nposition = $(this).closest("td").get(0);
var aPosition = oTable.fnGetPosition(nposition);
if (updatevalidDatarow()) {
$.ajax({
type: "POST",
url: "ajax_function/updatefn.asmx/updateName",
data: "{ 'prefix': '" + dataString + "'}",
contentType: "application/json; charset=utf-8",
dataType: "json",
success: function (data) {
var success = data.d;
if (success == "Record Updated") {
alertify.alert("Record is updated successfully.");
$('.edt1').replaceWith(upName);
$('.' + s).replaceWith(updatebtn);
$('.cnl_' + id).replaceWith("");
nEditing = null;
oTable.fnUpdate(upName, aPosition[0], 0, false);
oTable.fnDraw();
}
},
error: OnErrorCall
});
}
});
function OnErrorCall(response) {
alert(response.statusText);
}
$(".gvmyalign span").contents().unwrap();
oTable = $(".gvmyalign").dataTable({
"bJQueryUI": true,
"sPaginationType": "full_numbers"
});
});
</script>
Server Side:
Code Behind : updatefn.asmx
In updatefn.asmx we have a WebMethod updateName(), whicih fires Update query and return result stuatus. which we will display as resulting message on ajax call of success.
[WebMethod]
public string[] updateName(string prefix)
{
Listd = new List ();
string resultmessage = "";
string[] value = prefix.Split('=');
int update_id = Convert.ToInt32(value[0]);
string update_name = value[1];
int result = updateIndustry_Query(update_id, update_name);
if (result > 0)
{ resultmessage = "Record Updated"; }
d.Add(string.Format("{0}",resultmessage));
return d.ToArray();
}
Soundex Algorithm in C#
I caught the end of a conversation about the Soundex algorithm at work the other day which inspired me to write an implementation of it in C#. If you are not familiar with what Soundex is then the Wikipedia article on Soundex is a good place to start. I first came across this algorithm in a Natural Language Processing module during my university education. In a nutshell, when the Soundex algorithm is applied to a word, a Soundex Code is produced as output. Words that differ in spelling but sound the same (homophones) should produce the same Soundex Codes. For instance, "to" and "two" are spelt differently, but sound the same and therefore produce the same Soundex Code of "T000".
This is a useful little algorithm and I particularly like it for its simplicity and the fact that the heuristics used in the algorithm work well in most cases (one limitation of Soundex is that it falls short of covering words that sound the same but have a different first letter, e.g. "site" and "cite" produce different Soundex codes). Soundex is useful when writing search functionality where you want to account for misspellings in the users query. It's worth pointing out that SQL Server natively supports Soundex (see the Soundex function in T-SQL, for example).
My C# implementation is below - I opted to implement it in a static class that exposes one public method "For". You can download the Visual Studio solution from here (the zip contains a class library project with a corresponding test project). Note that the downloadable solution includes code comments.
This is a useful little algorithm and I particularly like it for its simplicity and the fact that the heuristics used in the algorithm work well in most cases (one limitation of Soundex is that it falls short of covering words that sound the same but have a different first letter, e.g. "site" and "cite" produce different Soundex codes). Soundex is useful when writing search functionality where you want to account for misspellings in the users query. It's worth pointing out that SQL Server natively supports Soundex (see the Soundex function in T-SQL, for example).
My C# implementation is below - I opted to implement it in a static class that exposes one public method "For". You can download the Visual Studio solution from here (the zip contains a class library project with a corresponding test project). Note that the downloadable solution includes code comments.
public static class Soundex
{
public static string For(string word)
{
const int MaxSoundexCodeLength = 4;
var soundexCode = new StringBuilder();
var previousWasHOrW = false;
word = Regex.Replace(
word == null ? string.Empty : word.ToUpper(),
@"[^\w\s]",
string.Empty);
if (string.IsNullOrEmpty(word))
return string.Empty.PadRight(MaxSoundexCodeLength, '0');
soundexCode.Append(word.First());
for (var i = 1; i < word.Length; i++)
{
var numberCharForCurrentLetter =
GetCharNumberForLetter(word[i]);
if (i == 1 &&
numberCharForCurrentLetter ==
GetCharNumberForLetter(soundexCode[0]))
continue;
if (soundexCode.Length > 2 && previousWasHOrW &&
numberCharForCurrentLetter ==
soundexCode[soundexCode.Length - 2])
continue;
if (soundexCode.Length > 0 &&
numberCharForCurrentLetter ==
soundexCode[soundexCode.Length - 1])
continue;
soundexCode.Append(numberCharForCurrentLetter);
previousWasHOrW = "HW".Contains(word[i]);
}
return soundexCode
.Replace("0", string.Empty)
.ToString()
.PadRight(MaxSoundexCodeLength, '0')
.Substring(0, MaxSoundexCodeLength);
}
private static char GetCharNumberForLetter(char letter)
{
if ("BFPV".Contains(letter)) return '1';
if ("CGJKQSXZ".Contains(letter)) return '2';
if ("DT".Contains(letter)) return '3';
if ('L' == letter) return '4';
if ("MN".Contains(letter)) return '5';
if ('R' == letter) return '6';
return '0';
}
}
Example: {
public static string For(string word)
{
const int MaxSoundexCodeLength = 4;
var soundexCode = new StringBuilder();
var previousWasHOrW = false;
word = Regex.Replace(
word == null ? string.Empty : word.ToUpper(),
@"[^\w\s]",
string.Empty);
if (string.IsNullOrEmpty(word))
return string.Empty.PadRight(MaxSoundexCodeLength, '0');
soundexCode.Append(word.First());
for (var i = 1; i < word.Length; i++)
{
var numberCharForCurrentLetter =
GetCharNumberForLetter(word[i]);
if (i == 1 &&
numberCharForCurrentLetter ==
GetCharNumberForLetter(soundexCode[0]))
continue;
if (soundexCode.Length > 2 && previousWasHOrW &&
numberCharForCurrentLetter ==
soundexCode[soundexCode.Length - 2])
continue;
if (soundexCode.Length > 0 &&
numberCharForCurrentLetter ==
soundexCode[soundexCode.Length - 1])
continue;
soundexCode.Append(numberCharForCurrentLetter);
previousWasHOrW = "HW".Contains(word[i]);
}
return soundexCode
.Replace("0", string.Empty)
.ToString()
.PadRight(MaxSoundexCodeLength, '0')
.Substring(0, MaxSoundexCodeLength);
}
private static char GetCharNumberForLetter(char letter)
{
if ("BFPV".Contains(letter)) return '1';
if ("CGJKQSXZ".Contains(letter)) return '2';
if ("DT".Contains(letter)) return '3';
if ('L' == letter) return '4';
if ("MN".Contains(letter)) return '5';
if ('R' == letter) return '6';
return '0';
}
}
// Both lines below output R100
Console.WriteLine(Soundex.For("Ravi"));
Console.WriteLine(Soundex.For("Ravee"));
Console.WriteLine(Soundex.For("Ravi"));
Console.WriteLine(Soundex.For("Ravee"));
Chủ Nhật, 9 tháng 6, 2013
C# Set Implementation (pre-.NET 3.5)
I was recently working on a .NET 3.0 project and found that this version of the framework didn't have any support for a mathematical Set collection. As of .NET 3.5 there is the System.Collections.Generic.HashSet implementation, however, I was working on a WinForms project and updating the framework on the client machines was out of scope for this piece of work.
I had some spare time available and thought it would be a good exercise to write a custom generic Set collection. The first step was to define an interface:
By inheriting from ICollection, we get all of the generally useful collection-based methods included in the ISet interface (e.g. Add, Clear, Contains etc.). I just had two methods to add to those, these were the set union and set intersection operations.
The next step was the implementation of the set. To keep things simple, I opted for a list-based implementation. I used the adapter pattern to map the ISet interface to a list interface. Therefore, the internal representation of the Set was actually an instance of System.Collections.Generic.List. By using this approach, I could delegate a lot of the method logic to use the list method implementations (i.e. Clear, Contains, CopyTo and Remove). The only custom logic I needed to write was the Add method (to avoid adding items already within the set), UnionWith method, IntersectWith method, ToString method and the readonly indexer. The implementation is below:
Example usage:
You can download the source files for the ISet interface and the ListBasedSet class from here.
I had some spare time available and thought it would be a good exercise to write a custom generic Set collection. The first step was to define an interface:
using System.Collections.Generic;
...
public interface ISet<T> : ICollection<T>
{
void UnionWith(ISet<T> set);
void IntersectWith(ISet<T> set);
}
...
public interface ISet<T> : ICollection<T>
{
void UnionWith(ISet<T> set);
void IntersectWith(ISet<T> set);
}
By inheriting from ICollection, we get all of the generally useful collection-based methods included in the ISet interface (e.g. Add, Clear, Contains etc.). I just had two methods to add to those, these were the set union and set intersection operations.
The next step was the implementation of the set. To keep things simple, I opted for a list-based implementation. I used the adapter pattern to map the ISet interface to a list interface. Therefore, the internal representation of the Set was actually an instance of System.Collections.Generic.List. By using this approach, I could delegate a lot of the method logic to use the list method implementations (i.e. Clear, Contains, CopyTo and Remove). The only custom logic I needed to write was the Add method (to avoid adding items already within the set), UnionWith method, IntersectWith method, ToString method and the readonly indexer. The implementation is below:
/// <summary>
/// A list-based implementation of a mathematical set.
/// </summary>
public sealed class ListBasedSet<T> : ISet<T>
{
private IList<T> _thisSet = new List<T>();
/// <summary>
/// Gets the number of elements contained in this set.
/// </summary>
public int Count { get { return _thisSet.Count; } }
/// <summary>
/// Gets a value indicating whether this set is readonly.
/// </summary>
public bool IsReadOnly { get { return false; } }
/// <summary>
/// Gets the item at the specified index in the set.
/// </summary>
/// <param name="i">
/// Index of the item to retrieve from the set.
/// </param>
/// <returns>Item at the specified index</returns>
public T this[int i] { get { return _thisSet[i]; } }
/// <summary>
/// Adds item into the set if this set does not already
/// contain the item.
/// </summary>
/// <param name="item">Item to add to the set.</param>
public void Add(T item)
{
if (!Contains(item))
_thisSet.Add(item);
}
/// <summary>
/// Clears the items from the set resulting in an empty set.
/// </summary>
public void Clear()
{
_thisSet.Clear();
}
/// <summary>
/// Determines if the specified item is within the set.
/// </summary>
/// <param name="item">
/// The object to locate in the set.
/// </param>
/// <returns>
/// true if item is found in the set; false otherwise.
/// </returns>
public bool Contains(T item)
{
return _thisSet.Contains(item);
}
/// <summary>
/// Copies the entire set to a one-dimensional array,
/// starting at the specified target index of the target
/// array.
/// </summary>
/// <param name="array">
/// The one-dimensional array to copy to.
/// </param>
/// <param name="arrayIndex">
/// The zero-based index in array at which copying begins.
/// </param>
public void CopyTo(T[] array, int arrayIndex)
{
_thisSet.CopyTo(array, arrayIndex);
}
/// <summary>
/// Removes the specified item from the set.
/// </summary>
/// <param name="item">Item to remove.</param>
/// <returns>
/// true if item is successfully removed; otherwise, false.
/// This method also returns false if item was not found
/// in the set.
/// </returns>
public bool Remove(T item)
{
return _thisSet.Remove(item);
}
/// <summary>
/// Returns an enumerator that iterates through the set.
/// </summary>
/// <returns>
/// An IEnumerator object that can be used to iterate
/// through the set.
/// </returns>
public IEnumerator<T> GetEnumerator()
{
return _thisSet.GetEnumerator();
}
/// <summary>
/// Returns an enumerator that iterates through the set.
/// </summary>
/// <returns>
/// An IEnumerator object that can be used to iterate
/// through the set.
/// </returns>
System.Collections.IEnumerator
System.Collections.IEnumerable.GetEnumerator()
{
return _thisSet.GetEnumerator();
}
/// <summary>
/// Modifies this set to contain all elements that are
/// present in itself, the specified collection, or both.
/// </summary>
/// <param name="otherSet">The set to union with.</param>
public void UnionWith(ISet<T> otherSet)
{
foreach (var item in otherSet)
Add(item);
}
/// <summary>
/// Modifies this set to contain only the elements that are
/// present in it and in the specified collection.
/// </summary>
/// <param name="otherSet">The set to intersect with.</param>
public void IntersectWith(ISet<T> otherSet)
{
var itemsToRemove = new List<T>();
for (int i = 0; i < Count; i++)
{
T item = this[i];
if (!otherSet.Contains(item))
itemsToRemove.Add(item);
}
foreach (var itemToRemove in itemsToRemove)
Remove(itemToRemove);
}
/// <summary>
/// Returns a string representation of this set
/// </summary>
/// <returns>A string representation of this set</returns>
public override string ToString()
{
var setStringBuilder = new StringBuilder();
setStringBuilder.Append("{");
foreach (var item in _thisSet)
setStringBuilder.Append(
string.Format(" {0},", item));
return string.Format("{0} }}",
setStringBuilder.ToString().TrimEnd(','));
}
}
/// A list-based implementation of a mathematical set.
/// </summary>
public sealed class ListBasedSet<T> : ISet<T>
{
private IList<T> _thisSet = new List<T>();
/// <summary>
/// Gets the number of elements contained in this set.
/// </summary>
public int Count { get { return _thisSet.Count; } }
/// <summary>
/// Gets a value indicating whether this set is readonly.
/// </summary>
public bool IsReadOnly { get { return false; } }
/// <summary>
/// Gets the item at the specified index in the set.
/// </summary>
/// <param name="i">
/// Index of the item to retrieve from the set.
/// </param>
/// <returns>Item at the specified index</returns>
public T this[int i] { get { return _thisSet[i]; } }
/// <summary>
/// Adds item into the set if this set does not already
/// contain the item.
/// </summary>
/// <param name="item">Item to add to the set.</param>
public void Add(T item)
{
if (!Contains(item))
_thisSet.Add(item);
}
/// <summary>
/// Clears the items from the set resulting in an empty set.
/// </summary>
public void Clear()
{
_thisSet.Clear();
}
/// <summary>
/// Determines if the specified item is within the set.
/// </summary>
/// <param name="item">
/// The object to locate in the set.
/// </param>
/// <returns>
/// true if item is found in the set; false otherwise.
/// </returns>
public bool Contains(T item)
{
return _thisSet.Contains(item);
}
/// <summary>
/// Copies the entire set to a one-dimensional array,
/// starting at the specified target index of the target
/// array.
/// </summary>
/// <param name="array">
/// The one-dimensional array to copy to.
/// </param>
/// <param name="arrayIndex">
/// The zero-based index in array at which copying begins.
/// </param>
public void CopyTo(T[] array, int arrayIndex)
{
_thisSet.CopyTo(array, arrayIndex);
}
/// <summary>
/// Removes the specified item from the set.
/// </summary>
/// <param name="item">Item to remove.</param>
/// <returns>
/// true if item is successfully removed; otherwise, false.
/// This method also returns false if item was not found
/// in the set.
/// </returns>
public bool Remove(T item)
{
return _thisSet.Remove(item);
}
/// <summary>
/// Returns an enumerator that iterates through the set.
/// </summary>
/// <returns>
/// An IEnumerator object that can be used to iterate
/// through the set.
/// </returns>
public IEnumerator<T> GetEnumerator()
{
return _thisSet.GetEnumerator();
}
/// <summary>
/// Returns an enumerator that iterates through the set.
/// </summary>
/// <returns>
/// An IEnumerator object that can be used to iterate
/// through the set.
/// </returns>
System.Collections.IEnumerator
System.Collections.IEnumerable.GetEnumerator()
{
return _thisSet.GetEnumerator();
}
/// <summary>
/// Modifies this set to contain all elements that are
/// present in itself, the specified collection, or both.
/// </summary>
/// <param name="otherSet">The set to union with.</param>
public void UnionWith(ISet<T> otherSet)
{
foreach (var item in otherSet)
Add(item);
}
/// <summary>
/// Modifies this set to contain only the elements that are
/// present in it and in the specified collection.
/// </summary>
/// <param name="otherSet">The set to intersect with.</param>
public void IntersectWith(ISet<T> otherSet)
{
var itemsToRemove = new List<T>();
for (int i = 0; i < Count; i++)
{
T item = this[i];
if (!otherSet.Contains(item))
itemsToRemove.Add(item);
}
foreach (var itemToRemove in itemsToRemove)
Remove(itemToRemove);
}
/// <summary>
/// Returns a string representation of this set
/// </summary>
/// <returns>A string representation of this set</returns>
public override string ToString()
{
var setStringBuilder = new StringBuilder();
setStringBuilder.Append("{");
foreach (var item in _thisSet)
setStringBuilder.Append(
string.Format(" {0},", item));
return string.Format("{0} }}",
setStringBuilder.ToString().TrimEnd(','));
}
}
Example usage:
ISet<string> set = new ListBasedSet<string>
{ "Mars", "Earth", "Pluto" };
ISet<string> otherSet = new ListBasedSet<string>
{ "Jupiter", "Earth", "Pluto", "Venus" };
ISet<string> earthSet = new ListBasedSet<string>
{ "Earth" };
ISet<string> emptySet = new ListBasedSet<string>();
set.UnionWith(otherSet);
Console.WriteLine("set UNION otherset = {0}", set);
Console.WriteLine("|set| (cardinality of set) = {0}", set.Count);
set.IntersectWith(earthSet);
Console.WriteLine("set INTERSECTION earthSet = {0}", set);
set.UnionWith(emptySet);
Console.WriteLine("set UNION emptySet = {0}", set);
set.IntersectWith(emptySet);
Console.WriteLine("set INTERSECTION emptySet = {0}", set);
{ "Mars", "Earth", "Pluto" };
ISet<string> otherSet = new ListBasedSet<string>
{ "Jupiter", "Earth", "Pluto", "Venus" };
ISet<string> earthSet = new ListBasedSet<string>
{ "Earth" };
ISet<string> emptySet = new ListBasedSet<string>();
set.UnionWith(otherSet);
Console.WriteLine("set UNION otherset = {0}", set);
Console.WriteLine("|set| (cardinality of set) = {0}", set.Count);
set.IntersectWith(earthSet);
Console.WriteLine("set INTERSECTION earthSet = {0}", set);
set.UnionWith(emptySet);
Console.WriteLine("set UNION emptySet = {0}", set);
set.IntersectWith(emptySet);
Console.WriteLine("set INTERSECTION emptySet = {0}", set);
You can download the source files for the ISet interface and the ListBasedSet class from here.
Thứ Tư, 15 tháng 5, 2013
Gridview Sorting on Header Click with Paging bind with DataTable in Asp.Net C#
Gridview Sorting on Column Header Click in Ascending / Decending order binding DataTable ASp.net c# with Paging
In this article im going to give some overview on how to SORT the data when user click on Gridview Header cell. Also I recommend you have a look at my Previous Article about Gridview Add/Update/Delete functionality.Though there are lot of articles on web which explains paging and sorting, theres some reasons which differs this article from other articles. ie Here Gridview control is bind with Datatable as in other article you found using ObjectDataSource also Paging not supported.
Recently I was working with GridView control and I was having manupulated Datatable as a DataSource to it. While solving this, I developed a good piece of code which I do feel will help most of you in your development activity.
HTML Markup :
- Set AllowPaging="True" and AllowSorting="True" Properties of GridView to enable paging and sorting respectively.
- Set PageSize property to mention how many records will be display on each page.
- Set SortExpression property of each column.
<asp:GridView ID="gvSortingPaging" runat="server" BorderColor="#999999" AutoGenerateColumns="False"
BorderWidth="1px" CellPadding="4" ForeColor="#333333" GridLines="None"AllowSorting="true" AllowPaging="true" PageSize="5" onsorting="gvSortingPaging_Sorting"
onpageindexchanging="gvSortingPaging_PageIndexChanging">
<AlternatingRowStyle BackColor="White" ForeColor="#284775" />
<Columns>
<asp:TemplateField HeaderText="Id">
<ItemTemplate>
<asp:Label ID="Label3" runat="server" Text='<%# Eval("id") %>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="First Name" SortExpression="FullName">
<ItemTemplate>
<asp:Label ID="Label4" runat="server" Text='<%# Eval("FullName") %>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Last Name" SortExpression="LastName">
<ItemTemplate>
<asp:Label ID="Label1" Text='<%# Eval("LastName") %>' runat="server"></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="MatchCount" SortExpression="matchCount">
<ItemTemplate>
<asp:Label ID="Label2" runat="server" Text='<%# Eval("matchCount") %>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
</Columns>
<EditRowStyle BackColor="#999999" />
<FooterStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" />
<HeaderStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" />
<PagerStyle BackColor="#284775" ForeColor="White" HorizontalAlign="Center" />
<RowStyle BackColor="#F7F6F3" ForeColor="#333333" />
<SelectedRowStyle BackColor="#E2DED6" Font-Bold="True" ForeColor="#333333" />
</asp:GridView>
Code Behind:
protected void Page_Load(object sender, EventArgs e){
if (!Page.IsPostBack)
{
gvSortingPaging.DataSource = populateGridView();
gvSortingPaging.DataBind();
}
}
public DataTable populateGridView()
{
string myQuery = "select id,FullName,LastName,matchCount from myTable";
SqlDataAdapter dap = new SqlDataAdapter(myQuery, con);
DataSet ds = new DataSet();
dap.Fill(ds);
return ds.Tables[0];
}
protected void gvSortingPaging_Sorting(object sender, GridViewSortEventArgs e)
{
string sortingDirection = string.Empty;
if (direction == SortDirection.Ascending)
{
direction = SortDirection.Descending;
sortingDirection = "Desc";
}
else
{
direction = SortDirection.Ascending;
sortingDirection = "Asc";
}
DataView sortedView = new DataView(populateGridView());
sortedView.Sort = e.SortExpression + " " + sortingDirection;
Session["objects"] = sortedView;
gvSortingPaging.DataSource = sortedView;
gvSortingPaging.DataBind();
}
Now here we we store direction in ViewState ie(Ascending or Decending).
public SortDirection direction
{
get
{
if (ViewState["directionState"] == null)
{
ViewState["directionState"] = SortDirection.Ascending;
}
return (SortDirection)ViewState["directionState"];
}
set
{ ViewState["directionState"] = value; }
}
protected void gvSortingPaging_PageIndexChanging(object sender, GridViewPageEventArgs e)
{
gvSortingPaging.PageIndex = e.NewPageIndex;
gvSortingPaging.DataSource = Session["objects"];
gvSortingPaging.DataBind();
}
Đăng ký:
Bài đăng (Atom)

