[karsten samaschke]

Thanks for that but I have a dropdown and on the onclick of a Button I want the page to go to a URL in the dropdown(its value is held in the Value of the option) but I'm not sure how to do this in the attributes section below. Any suggestions would be great?


Dim drpEditControl = New DropDownList()
Dim btnGo = New Button()

--then code to populate dropdown

btnGo.Attributes.Add("onClick", "")

'add dropdown list to the page
Me.Controls.Add(drpEditControl)
Me.Controls.Add(btnGo)

But, using this method the form validation is ignored and thus only works if you are not validating. Any ideas?

There's a much more elegant way to handle events in dynamically created controls:

Dim objButton As New Button
objButton.Text = "Click me!"
objButton.ID = "ButtonID"
AddHandler objButton.Click, AddressOf Button_Click()

Sub Button_Click(ByVal sender As System.Object, ByVal e As System.EventArgs)
Dim sButton As String = CType(sender, Button).ID
templabel.Text = "The Button " & sButton & "was clicked."
End Sub

But this way works only if the button is added in the sub Page_load. If you add the button in other subs, you are not be able to handle events of the button, because on postback the button is not present in the page.

For C# users, use objButton.Click+=new System.EventHandler(this.btnChecklist_Click);

How to get the botton ID in 'this.btnChecklist_Click'

After working with the AddHandler, I would have to agree with the original article. I would also say that Microsoft has really missed the boat when it comes to using Dynamic Controls and the AddHandler. The proof of this becomes apparent when you begin nesting controls within controls.

What if I create more than one dynamic buttons?
Then I can't use uniqueID, right? How should I distinguise which button has been clicked?

I'm sorry i've got it..it was dumb question..

I have tried using the second method in c#=

Dim objButton As New Button
objButton.Text = "Click me!"
objButton.ID = "ButtonID"
AddHandler objButton.Click, AddressOf Button_Click()
------------------------------------------
Sub Button_Click(ByVal sender As System.Object, ByVal e As System.EventArgs)
Dim sButton As String = CType(sender, Button).ID
templabel.Text = "The Button " & sButton & "was clicked."
End Sub
------------------------------------------

My code looks like this:
-------------------------------------------
Button btnSubmitScore = new Button();

btnSubmitScore.Text = "Submit";

btnSubmitScore.Click += new System.EventHandler(this.btnMenu_Click);

dgPhrase.Items[iItems].Cells[3].Controls.Add(btnSubmitScore);
------------------------------------------
It appears that btnMenu_Click never gets called. The page simply does a post back. btnMenu_Click should redirect to a new page. Any ideas about what I am doing wrong?

I have the following in c# which fails ever to register the eventhandler (never gets called). Is someone saying that this code needs to be on Page_Load ?

...
btnAddFile.Text = "Add File";

// add the button
cell.Controls.Add(btnAddFile);

btnAddFile.Click += new System.EventHandler(this.btnAdd_Click);
....

No, I do not think you need to have the code in the Page Load event. Here's a sample code which creates a DropDownList (adds it to the table cell of an asp table) and a Button (which text Click - adds this to the Page) when the Button on the page is clicked. When you click the Click button after adding the controls on fly the Label at the bottom gets displayed with the Selected text on the dropdown.

Enjoy Coding.

***********HTML****************************
<asp:Table ID="tbl1" Runat="server" Width="200px">
<asp:TableRow ID="tr1" Runat="server" Width="100%">
<asp:TableCell ID="tc1" Runat="server" Width="50%"></asp:TableCell>
</asp:TableRow>
<asp:TableRow ID="trlink" Runat="server" Width="100%">
<asp:TableCell ID="tclink" Runat="server" Width="50%">
<asp:Button id="Button1" runat="server" Text="Button"></asp:Button>
</asp:TableCell>
</asp:TableRow>
</asp:Table>
<asp:Label id="Label1" style="Z-INDEX: 101; LEFT: 24px; POSITION: absolute; TOP: 224px" runat="server"
Width="312px">Label</asp:Label>
<asp:Label id="Label2" style="Z-INDEX: 102; LEFT: 24px; POSITION: absolute; TOP: 256px" runat="server"
Width="312px">Label</asp:Label>

***********************************************


******Code Behind ****************************

public class WebForm1 : System.Web.UI.Page
{
protected System.Web.UI.WebControls.Button Button1;
protected System.Web.UI.WebControls.Label Label1;
protected System.Web.UI.WebControls.Label Label2;
protected System.Web.UI.WebControls.DropDownList DropDownList1;
protected System.Web.UI.WebControls.Table tbl1;

private void Page_Load(object sender, System.EventArgs e)
{
if(IsPostBack)
{
CreateButtons();}
}

#region Web Form Designer generated code
override protected void OnInit(EventArgs e)
{
//
// CODEGEN: This call is required by the ASP.NET Web Form Designer.
//

InitializeComponent();
base.OnInit(e);
}

/// <summary>
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
/// </summary>
private void InitializeComponent()
{
this.Load += new System.EventHandler(this.Page_Load);

}
#endregion

private void Button1_Click(object sender, System.EventArgs e)
{
CreateButtons();
}

private void btn_Click(object sender, EventArgs e)
{
Label1.Text = "Button was clicked";
}

private void ddl_SelectedIndexChanged(object sender, EventArgs e)
{
DropDownList ddl1 = new DropDownList();
ddl1 = (DropDownList)Page.FindControl("Form1").FindControl("tbl1").FindControl("tr1").FindControl("tc1").FindControl("ddl1");
if(ddl1 != null){Label2.Text = ddl1.SelectedItem.Text;}
}

private void CreateButtons()
{
DropDownList ddl = new DropDownList();
ddl.Items.Add("1");
ddl.Items.Add("2");
ddl.Items.Add("3");
ddl.ID = "ddl1";
DropDownList ddl1 = new DropDownList();
ddl1 = (DropDownList) Page.FindControl("Form1").FindControl("tbl1").FindControl("tr1").FindControl("tc1").FindControl("ddl1");
if(ddl1 == null){
Page.FindControl("Form1").FindControl("tbl1").FindControl("tr1").FindControl("tc1").Controls.Add(ddl);
ddl.SelectedIndexChanged += new EventHandler(ddl_SelectedIndexChanged);}

Button btn1 = new Button();
btn1 = (Button)Page.FindControl("Form1").FindControl("btn1");
if(btn1 == null){
Button btn = new Button();
btn.Text = "Click";
btn.ID = "btn1";

Page.FindControl("Form1").Controls.Add(btn);
btn.Click += new EventHandler(btn_Click);}
}


}


***************************************************

when a button is clicked on i want it to go to another page. how do i do this?

then use validation controls on client side before postback

I found out that in order for the original code to work, you must add an ID to the button after you created it, e.g.
objButton.ID = "butTest"

hi,

let me know how to add button click event dynamically in placeholder.

In my program , i created a link button. after clicking the linkbutton some controls(textbox,label ,button) are dynamically added to the form.

In that dynamic controls i want to add button click.

protected void LinkButton1_Click(object sender, EventArgs e)

   {

Button b1 = new Button();

b1.ID = "button";

PlaceHolder1.Controls.Add(b1);

      b1.Click+=new EventHandler(this.b1_Click);

           }

private void b1_Click(object sender, EventArgs e)

   {

      labe1.text="welcome";

   }  

In the code program does't handle the button click event.

hi,

i have two dropdown lists namely SDU & support

Format is:

SDU (dropdown list)                    Support(dropdown list)

                                   Add(button)

when i click on the add button i want the same two drop down lists i.e., SDU& Support to be displayed

like:

SDU (dropdown list)                    Support(dropdown list)

SDU (dropdown list)                    Support(dropdown list)

                                   Add(button)

and so on...................

using asp, how can i code it?

Please help me

its urgent

I know I'm quite late for this post. But is there a possibility to use this this way in C#, because in C# I don't have a

HttpRequest.Item()

Method. And after some search with no results I hope know you coult help me.

how do i validate textbox generated dynamically for only numbers.

hi tejaswini  s,

Try this..

Add_Click()

{

DropDownList DD1 = new DropDownList();

foreach(ListItem LI in SDU.Items)

{

 DD1.Items.Add(LI);

}

DropDownList DD2 = new DropDownList();

foreach(ListItem LI in Support.Items)

{

 DD2.Items.Add(LI);

}

}

//Thanks n regard

Dim objButton As New Button

objButton.Text = "Click me!"

objButton.ID = "ButtonID"

AddHandler objButton.Click, AddressOf Button_Click()

Sub Button_Click(ByVal sender As System.Object, ByVal e As System.EventArgs)

Dim sButton As String = CType(sender, Button).ID

templabel.Text = "The Button " & sButton & "was clicked."

End Sub

i have tried the code

but error generetd telling

"Argument not specified for parameter 'e' of 'Public Sub Button_Click(sender As Object, e As System.EventArgs)'."

@ Shoyeb

Had the same error

Lose the parentheses at button_click

so it will be

AddHandler objButton.Click, AddressOf Button_Click

The rest should work

See Alternate and easy way to generate dynamic buttons:

urenjoy.blogspot.com/.../add-dynamic-buttons-and-handle-click.html

hi,

I want to add more then 1 link buttons dynamically. i added them using the for loop .so how i will come to knw that which link button is clicked???. on every linkbutton click i want to display different images in the pop up window.

This post is quite old, but the following information might be useful to somebody.

Add your controls in the OnInit method by overriding it, then your button event will be executed:

protected override void OnInit(EventArgs e)

{

// Add your button dynamiccaly here base.OnInit(e);

}

Information found on: support.microsoft.com/.../en-us

Hi

I am dynamically adding link buttons to my page using  for loop. I know the count of link buttons created only at run time. Depending on link button clicked i want to display different messges. But how do i know which link button was clicked

please can anyone help me. its really urgent

Hi there,

I need to add buttons with event handles dynamically by pressing another button -let's say static one-. How this dream can be achieved?!

I'd appreciate solving it!

hiii...

i have following code

Dim d As New Button

d.Text = "add"

d.Attributes.Add("onclick", "")

i want to page is redirect to another page on click event of add... what should i do???

Please reply...

hi i beginners in asp.net programming site .

i have query about to creating button at run time .

  Actually my requirement is i will have random number of button ,i need to create  on  page all button and onclicking any one of button it should give its ID value ...

thanks, helpful post.

2011 and this post is still coming in handy.  

@anju and others re picking up which button was clicked:

In your loop that dynamically creates the buttons, give each a unique ID such as btnClick_1, btnClick_2...

The event sub should take a "sender as Object" parameter, just like the event handlers for controls you create at design time.

Then you can pick up the loop number from the clicked button with the following line:

buttonID = Val(CType(sender, Button).ID.Split("_")(1))

(I'm using VB here, but the same principle will apply in C - split the string at the "_" or whatever delimiter you use when you assign the button IDs)