To create a web part class, open your visual studio, create a
new Class Library Project and name it as "TestAbdelHaqWebpart." Then
add a new class and name it "MyAjaxWebPart."
First of all, you have to add some references to the project
which are listed below:
·
System.Web
·
System.Web.Extensions
·
System.Web.Extensions.Design
In addition, you need to inherit the WebPart class.
Take a look at listing 1; it is our Ajax WebPart class.
Listing 1
Imports System
Imports System.Collections.Generic
Imports System.ComponentModel
Imports System.Text
Imports System.Web
Imports System.Web.UI
Imports System.Web.UI.WebControls
Imports System.Web.UI.WebControls.WebParts
Imports System.Data
Imports System.Data.SqlClient
Public Class MyAjaxWebPart
Inherits WebPart
Private _grdSearch As GridView
Private _txtSearch As TextBox
Private _btnSearch As Button
Private _lblMsg As Label
Private _updatePanel As UpdatePanel
Private _updateProgress As UpdateProgress
Private Shared ReadOnly EventSubmitKey As New Object()
Public NewAjaxWebPart12()
Public Sub New()
Me.ExportMode = WebPartExportMode.All
End Sub
<WebBrowsable(True), _
Personalizable(PersonalizationScope.Shared), _
Category("AbdHaq Property") _
> _
Public Property LoadingImageURL() As String
Get
Dim _obj As Object = ViewState("LoadingImageURL")
If _obj Is Nothing Then
Return String.Empty
Else
Return DirectCast(ViewState("LoadingImageURL"), String)
End If
End Get
Set(ByVal value As String)
ViewState("LoadingImageURL") = value
End Set
End Property
Public Custom Event Submit As EventHandler
AddHandler(ByVal value As EventHandler)
Events.AddHandler(EventSubmitKey, value)
End AddHandler
RemoveHandler(ByVal value As EventHandler)
Events.RemoveHandler(EventSubmitKey, value)
End RemoveHandler
RaiseEvent(ByVal sender As Object, _
ByVal e As System.EventArgs)
CType(Events(EventSubmitKey), _
EventHandler).Invoke(sender, e)
End RaiseEvent
End Event
Private Sub _btnSearch_Click(ByVal source As Object, ByVal e As EventArgs)
_grdSearch.Visible = False
System.Threading.Thread.Sleep(1500)
'//Create DataTable Structure
Dim Dtable = New DataTable("tmpTable")
'//User_ID Col
Dtable.Columns.Add("User_ID", GetType(Integer))
Dtable.Columns("User_ID").AutoIncrement = True
Dtable.Columns("User_ID").AutoIncrementSeed = 1
'//User_Name Col
Dtable.Columns.Add("User_Name", GetType(String))
'//User_Department Col
Dtable.Columns.Add("User_Department", GetType(String))
Dim dr As DataRow
dr = Dtable.NewRow
dr("User_Name") = "Abdulla Abdelhaq"
dr("User_Department") = "Technical"
Dtable.Rows.Add(dr)
dr = Dtable.NewRow
dr("User_Name") = "Noura Ahmad"
dr("User_Department") = "Technical"
Dtable.Rows.Add(dr)
dr = Dtable.NewRow
dr("User_Name") = "Oday Mohammad"
dr("User_Department") = "Production"
Dtable.Rows.Add(dr)
Dim _searchFor As String = "%"
If _txtSearch.Text <> String.Empty Then
_searchFor = _txtSearch.Text
End If
Dim dtView As New DataView(Dtable)
dtView.RowFilter = "User_Name LIKE '%'+'" & _searchFor & "'+'%'"
If dtView.Count > 0 Then
_grdSearch.Visible = True
_grdSearch.AutoGenerateColumns = True
_grdSearch.DataSource = dtView
_grdSearch.DataBind()
_lblMsg.Text = String.Empty
Else
_lblMsg.Text = "<font color='red'>Sorry, No Data Found!.</font>"
_grdSearch.Visible = False
End If
End Sub
Protected Overrides Sub CreateChildControls()
Controls.Clear()
_updatePanel = New UpdatePanel
With _updatePanel
.ID = "UpdatePanel1"
.ChildrenAsTriggers = True
.UpdateMode = UpdatePanelUpdateMode.Conditional
End With
_updateProgress = New UpdateProgress
_updateProgress.ID = "UpdateProgress1"
Dim _templateHTML As String
If LoadingImageURL = String.Empty Then
_templateHTML = "<span>Loading ...</span>"
Else
_templateHTML = "<div><img alt='Loading...' src='" & _
LoadingImageURL.Trim & "'/></div>"
End If
_updateProgress.ProgressTemplate = New ProgressTemplate(_templateHTML)
_updateProgress.AssociatedUpdatePanelID = _updatePanel.ClientID
Me.Controls.Add(_updatePanel)
_grdSearch = New GridView
_grdSearch.ID = "GrdSearch"
_txtSearch = New TextBox
_txtSearch.ID = "txtSearch"
_btnSearch = New Button
_btnSearch.Text = "Search"
_btnSearch.ID = "BtnSearch"
_lblMsg = New Label
_lblMsg.ID = "lblMsgError"
AddHandler _btnSearch.Click, AddressOf _btnSearch_Click
_updatePanel.ContentTemplateContainer.Controls.Add(_txtSearch)
_updatePanel.ContentTemplateContainer.Controls.Add(_btnSearch)
_updatePanel.ContentTemplateContainer.Controls.Add(_grdSearch)
_updatePanel.ContentTemplateContainer.Controls.Add(_lblMsg)
_updatePanel.ContentTemplateContainer.Controls.Add(_updateProgress)
End Sub
Protected Overrides Sub OnInit(ByVal e As EventArgs)
MyBase.OnInit(e)
'get the existing ScriptManager if it exists on the page
Dim _AjaxManager As ScriptManager = ScriptManager.GetCurrent(Me.Page)
If _AjaxManager Is Nothing Then
'create new ScriptManager and EnablePartialRendering
_AjaxManager = New ScriptManager()
_AjaxManager.EnablePartialRendering = True
'Fix problem with postbacks and form actions (DevDiv 55525)
Page.ClientScript.RegisterStartupScript(Me.GetType, Me.ID, _
"_spOriginalFormAction = document.forms[0].action;", True)
'tag:"form" att:"onsubmit" val:"return _spFormOnSubmitWrapper()"
'blocks async postbacks after the first one
'not calling "_spFormOnSubmitWrapper()" breaks all postbacks
'returning true all the time, somewhat defeats the purpose of the
'_spFormOnSubmitWrapper() which is to block repetitive postbacks,
'but it allows MS AJAX Extensions to work properly
If Not Me.Page.Form Is Nothing Then
Dim formOnSubmitAtt As String = Me.Page.Form.Attributes("onsubmit")
If Not String.IsNullOrEmpty(formOnSubmitAtt) And _
formOnSubmitAtt = "return _spFormOnSubmitWrapper();" Then
Me.Page.Form.Attributes("onsubmit") =_
"_spFormOnSubmitWrapper();"
End If
'add the ScriptManager as the first control in the Page.Form
Me.Page.Form.Controls.AddAt(0, _AjaxManager)
End If
End If
End Sub
Protected Overrides Sub RenderContents(ByVal writer As _
System.Web.UI.HtmlTextWriter)
_updatePanel.RenderControl(writer)
End Sub
End Class
'Class for Building progress tempales
Public Class ProgressTemplate : Implements ITemplate
Private template As String
Public Sub New(ByVal temp As String)
template = temp
End Sub
Public Sub InstantiateIn(ByVal container As Control) Implements _
Web.UI.ITemplate.InstantiateIn
Dim ltr As New LiteralControl(Me.template)
container.Controls.Add(ltr)
End Sub
End Class 
