RadAjax for ASP.NET
Contents
Update in composite control Send comments on this topic.
See Also
AJAX Manager > How-To > Update in composite control

Glossary Item Box

This topic demonstrates a possible scenario of AJAX Manager updates controls from a composite control. It is important to set IDs of instantiated controls as well as adding them into controls collection. A necessary AJAX setting could be added at CreateChildControls method, however this must be done after controls are added into corresponding controls collection.

The example below includes a single AJAX Manager control on the page. Here is the code-behind:

C# Copy Code
public partial class Default : System.Web.UI.Page
{
   TestComposite Tst1;
   protected void Page_Load(object sender, EventArgs e)
   {
       Tst1 = new TestComposite(RadAjaxManager1, "1");
       //set an ID of instantiated control!
       Tst1.ID = "tst1";
       this.form1.Controls.Add(Tst1);
   }
   protected void RadAjaxManager1_AjaxRequest(object sender, Telerik.WebControls.AjaxRequestEventArgs e)
   {
       //Update control from the composite on AJAX request
       Tst1.controLbl.Text = Tst1.controTB.Text;
   }
}  
VB.NET Copy Code
Public Partial Class [Default]
 Inherits System.Web.UI.Page
 Private Tst1 As TestComposite
 Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)
  Tst1 = New TestComposite(RadAjaxManager1, "1")
  'set an ID of instantiated control!
  Tst1.ID = "tst1"
  Me.form1.Controls.Add(Tst1)
 End Sub
 Protected Sub RadAjaxManager1_AjaxRequest(ByVal sender As Object, ByVal e As Telerik.WebControls.AjaxRequestEventArgs)
  'Update control from the composite on AJAX request
  Tst1.controLbl.Text = Tst1.controTB.Text
 End Sub
End Class

And the composite control class:

C# Copy Code
public class TestComposite : CompositeControl
 {
   private Telerik.WebControls.RadAjaxManager m_radAm;
   private string m_UniqueId;
   public TextBox MyTxt;
   public Label MyLbl;
   public TestComposite(Telerik.WebControls.RadAjaxManager radAm, string UniqueId)
   {
     m_radAm = radAm;
     m_UniqueId = UniqueId;
   }
   protected override void RecreateChildControls()
   {
     EnsureChildControls();
   }
   protected override void CreateChildControls()
   {
     MyTxt = new TextBox();
     MyLbl = new Label();
     //set IDs of instantiated controls!
     MyLbl.ID = "Lbl_" + m_UniqueId;
     MyTxt.ID = "Txt_" + m_UniqueId;
     MyLbl.Text = "LabelText";
     //add the controls into controls collection!
     this.Controls.Add(MyTxt);
     this.Controls.Add(MyLbl);
     //Manually add AJAX request triggered on onBlur client event of the text box
     MyTxt.Attributes.Add("onBlur", m_radAm.GetAjaxEventReference(MyTxt.ClientID));
     //Add the ajax setting - this should be done after controls are added into controls collection
     m_radAm.AjaxSettings.AddAjaxSetting(m_radAm, MyLbl);
   }
   public TextBox controTB
   {
     get {
         return MyTxt;
     }
   }
   public Label controLbl
   {
     get
     {
         return MyLbl;
     }
   }
   protected override void Render(HtmlTextWriter output)
   {
       MyTxt.RenderControl(output);
       MyLbl.RenderControl(output);
   }
 }
VB.NET Copy Code
Public Class TestComposite
 Inherits CompositeControl
 Private m_radAm As Telerik.WebControls.RadAjaxManager
 Private m_UniqueId As String
 Public MyTxt As TextBox
 Public MyLbl As Label
 Public Sub New(ByVal radAm As Telerik.WebControls.RadAjaxManager, ByVal UniqueId As String)
  m_radAm = radAm
  m_UniqueId = UniqueId
 End Sub
 Protected Overloads Overrides Sub RecreateChildControls()
  EnsureChildControls()
 End Sub
 Protected Overloads Overrides Sub CreateChildControls()
  MyTxt = New TextBox()
  MyLbl = New Label()
  'set IDs of instantiated controls!
  MyLbl.ID = "Lbl_" + m_UniqueId
  MyTxt.ID = "Txt_" + m_UniqueId
  MyLbl.Text = "LabelText"
  'add the controls into controls collection!
  Me.Controls.Add(MyTxt)
  Me.Controls.Add(MyLbl)
  'Manually add AJAX request triggered on onBlur client event of the text box
  MyTxt.Attributes.Add("onBlur", m_radAm.GetAjaxEventReference(MyTxt.ClientID))
  'Add the ajax setting - this should be done after controls are added into controls collection
  m_radAm.AjaxSettings.AddAjaxSetting(m_radAm, MyLbl)
 End Sub
 Public ReadOnly Property controTB() As TextBox
  Get
   Return MyTxt
  End Get
 End Property
 Public ReadOnly Property controLbl() As Label
  Get
   Return MyLbl
  End Get
 End Property
 Protected Overloads Overrides Sub Render(ByVal output As HtmlTextWriter)
  MyTxt.RenderControl(output)
  MyLbl.RenderControl(output)
 End Sub
End Class

 

See Also