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My page behind code created button onclick function isnt working

I have created button manually from the behind code page using asp.net WebForms.
That is the creation code:
Button myButton = new Button();
myButton.ID = "b" + arrcodes[i];
myButton.Text = "Buy Now!";
myButton.CssClass = "btn-primary";
myButton.Click += new EventHandler(myButton_Click);
myPlaceHolder.Controls.Add(myButton);
I googled how to add onClick function and used method which founded here in stackoverflow. But this method not working.. the function "myButton_Click" isnt activated when i press the button.
protected void myButton_Click(object sender, EventArgs e)
{ // my code }
Have i did something wrong?

You will need to reload that dynamically created button on postback with same Id inside Page_Init or Page_Load event.
Otherwise, it won't be in the Control Tree, and cannot trigger the Click event.
For example,
public partial class Default : System.Web.UI.Page
{
protected void Page_Init()
{
CreateButton();
}
protected void myButton_Click(object sender, EventArgs e)
{
}
private void CreateButton()
{
Button myButton = new Button();
myButton.ID = "b1";
myButton.Text = "Buy Now!";
myButton.CssClass = "btn-primary";
myButton.Click += new EventHandler(myButton_Click);
myPlaceHolder.Controls.Add(myButton);
}
}

Usually, the better option is to create the button and toggle it's visibility.
If you really need to create it dynamically, make sure you're creating the button in OnInit method for event handler to work.

How can I invoke a server-side event from jQuery (Sharepoint 2010)?

In my Sharepoint 2010 app, I'm handling most events client-side with jQuery. However, for the saving of data to the Sharepoint list, and the generation of a PDF file with that data, I want to handle that server-side, with C#.
I tried to invoke a C# event this way:
0) Aded an HTML button in my project's *.ascx file:
<button type="button" name="saveData" id="saveData">Save Data</button>
1) Added jQuery to respond to that button being clicked (in the same *.ascx file):
$("#saveData").click(function () {
$('#hiddenSave').trigger('valuechanged');
});
2) Created a hidden element in the server-side C# (in the *.ascx.cs file):
HiddenField hiddenSave = null;
protected void Page_Load(object sender, EventArgs e)
{
base.OnPreRender(e);
hiddenSave = new HiddenField();
hiddenSave.ID = "hiddenSave";
hiddenSave.ValueChanged += new EventHandler(hiddenSave_ValueChanged);
this.Controls.Add(hiddenSave);
}
protected void hiddenSave_ValueChanged(object sender, EventArgs e)
{
GeneratePDF();
}
private void GeneratePDF()
{
;//bla
}
But I never reach the "ValueChanged" event handler; $("#saveData").click() fires, but not hiddenSave_ValueChanged().
So do I need a tweak to this, or a completely different approach? How can I do as much as possible client-side with jQuery, but also run server-side/C# code where necessary, in a Sharepoint 2010 app?
UPDATE
A little more detail, and about additional things I've tried: I'm creating a button on a Sharepoint page dynamically (in C#) in my *.ascx.cs file:
Button btnSave = null;
protected void Page_Load(object sender, EventArgs e)
{
base.OnPreRender(e);
this.Controls.Add(new LiteralControl("<br />"));
btnSave = new Button();
btnSave.ID = "btnSave";
btnSave.Text = "Save the Data";
btnSave.Click += new EventHandler(btnSave_Click);
btnSave.Visible = false;
this.Controls.Add(btnSave);
}
protected void btnSave_Click(object sender, EventArgs e)
{
btnSave.Text = "You clicked me!";
PostTravelData ptd = new PostTravelData();
}
I set it visible at the right time in the client-side jQuery in the *.ascx file:
$('#btnSave').show();
However, clicking the button does not reach the btnSave_Click() event - the breakpoint there is never reached, nor is the button's text changed. Why not?
Even when I don't set the button invisible (comment out the "btnSave.Visible = false;" line), the click handler isn't reached...is Page_Load() too late? Is there an earlier page event I can use that would work?
I tried moving it from Page_Load() to OnPreRender(), too, like this:
protected void OnPreRender(EventArgs e)
{
this.Controls.Add(new LiteralControl("<br />"));
btnSave = new Button();
btnSave.ID = "btnSave";
btnSave.Text = "Save the Data";
btnSave.Click += new EventHandler(btnSave_Click);
//btnSave.Visible = false;
this.Controls.Add(btnSave);
}
...(and OnRender()) but the button doesn't even display...
And, trying a different tack, I commented out the dynamic creation server-side code and tried to attach to a button created in the HTML (*.ascx file):
<button type="button" name="saveData" id="saveData" runat="server" onclick="saveData_Click">Save Data</button>
(by adding the "runat server" and the onclick handler), and then adding this "code-behind" (*.ascx.cs)):
protected void saveData_Click(object sender, EventArgs e)
{
PostTravelData ptd = new PostTravelData();
SaveToList(ptd);
GeneratePDF(ptd);
}
...but there was still no joy in Mudville -- the breakpoint in the handler is not reached.
Yet another attempt was:
In the *.ascx:
<asp:Button runat="server" id="saveData" name="saveData" onclick="saveData_Click" Text="Bla" />
In the code-behind:
saveData.Click += saveData_Click;
The "Bla" button is created, but clicking on it reaches not the breakpoint in the "saveData_Click" handler.
I even adapted some code from here like so:
Button btnSave = null;
. . .
protected override void CreateChildControls()
{
btnSave = new Button();
btnSave.Width = new Unit(150, UnitType.Pixel);
btnSave.Text = "Can you see me?";
btnSave.Click += new EventHandler(btnSave_Click);
Controls.Add(btnSave);
}
...but I still do not reach the "protected void btnSave_Click(object sender, EventArgs e)" handler when I click the button.
Surely there's a way to get a handle on the button server-side and manipulate it (specifically, respond to its click event)...?!?

First of all, as far as I know, there is no such event for input type hidden in a ascx page. If you create the input type hidden with runat server in the ascx code then you'll see that when you try to add this event it's not available. However there are other events like OnClick that you can simulate to get the desired result.

How to change imagebutton click event method

I have an imagebutton which i set up at design time via the designer and assigned a method to its Click event. I need to now change that buttons target event method dynamically.
I have tried this by setting the following code but it doesn't seem to alter the target event for the imagebutton to my desired method 'imgBtnFw_Click_Details'
imgBtn.Click +=new ImageClickEventHandler(imgBtnFw_Click_Details);
Im thinking maybe i need to detach the currently assigned click event but not sure.
Does anybody have a correct set of steps for switching the target firing event method?

Its working...
Event Binding..
protected void Page_Load(object sender, EventArgs e)
{
if (Page.IsPostBack)
{
imgBtn.Click -= ImageButton1_Click; // remove previous handler
imgBtn.Click +=imgBtnFw_Click_Details; // add new handler
}
}
Event handler ...
protected void imgBtnFw_Click_Details(object sender, ImageClickEventArgs e)
{
//your implementation
}

How can i catch onclick event of Dynamically loaded control?

I have a dropdownlist (on Page) which has OnSelectedIndexChange event thats Loads different Control (ascx) dynamically each time ( with LoadControl Command) - into the page.
Each Control Has a Button(runat=server) and TextBox(runat=server).
When i click on the button - i cant get into the Onclick function .
How can i get into the OnClick Function of the Ascx ?
I know that each SelectedIndexChange its makes postback - so i know i have to save something in the viewstate. but i dont know how to save it and later get the values eneterd on the TexstBox. ( of Each ascx)

You need to add an event handler to the user control, like this:
public event EventHandler ButtonClick;
And in the click event of the button:
protected void Button1_Click(object sender, EventArgs e)
{
if (this.ButtonClick != null)
this.ButtonClick(this, e);
}
Then, from the page, you can get the click event like this:
<UC:MyUserControl ID="UserControl1" runat="server" OnButtonClick="UserControl1_ButtonClick" ... />
protected void UserControl1_ButtonClick(object sender, EventArgs e)
{
//Handle the click event here
}
If you're loading the controls dynamically, then you'll need to make sure the controls are rehydrated after postback, and emulate the code above by assinging the event handler through code:
MyUserControl ctrl = (MyUserControl)this.LoadControl("...");
ctrl.ButtonClick += new EventHandler(UserControl1_ButtonClick);

How do I attach an event handler to an ASP.NET control created at runtime?

Good morning everybody.
I have a question connected with controls and event handling. Lets say I want to create a LinkButton.
protected void loadLinkButton()
{
ContentPlaceHolder content = (ContentPlaceHolder)this.Master.FindControl("MainContent");
LinkButton lnk = new LinkButton();
lnk.ID = "lnikBtn";
lnk.Text = "LinkButton";
lnk.Click += new System.EventHandler(lnk_Click);
content.Controls.Add(lnk);
}
Here is the event handler:
protected void lnk_Click(object sender, EventArgs e)
{
Label1.Text = "ok!";
}
If I run the loadLinkButton function inside Page_Load everything is ok. But when I try to run the loadLinkButton by clicking simple button, link button is created but event is not handled.
protected void Button1_Click(object sender, EventArgs e)
{
loadLinkButton();
}
I there any way to solve it? Or loadLinkButton must always regenerated on Page_Load, Page_init etc.

When working with dynamic controls, I always add the control in Page_Init, because viewstate loading will happen right after Init. If you add it to Page_Load, there is a chance that you will lose viewstate. Just make sure you provide a unique control ID.

It is important to know how ASP.Net determines which events to invoke. The source of each event is passed using a hidden field:
<input type="hidden" name="__EVENTTARGET" value="" />
Whenever the page loads, it pulls in the source of the event from that field and then determines which event to invoke. Now this all works great for controls added through markup because the entire control tree is regenerated on every request.
However, your control was only added once. When a Postback occurs, your control no longer exists as a Server control in the tree, and therefore the event never fires.
The simply way to avoid this is to make sure your Dynamic Controls are added every time the page loads, either through the Page_Init event, or the Page_Load event.

You are right. This is the expected behavior. Page_Load and Page_Init would be the events where you should be adding it.

That would be because when you click your dynamically generated linkbutton, you do a postback to the server. There you do an entirely new pageload, but your original buttonclick (that generates the link) never happened now, so the linkbutton is never made, and the event can not be thrown.
An alternative is to add the linkbutton you add dynamically, to your page statically, with Visible = false. And when you click the other button, make it visible.

I am not exactly sure what problem you are facing but you should put the dynamic controls code in Page_Init as suggested by #johnofcross:
public partial class WebForm1 : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
protected void Page_Init(object sender, EventArgs e)
{
CreateControls();
}
private void CreateControls()
{
var lb = new LinkButton();
lb.Text = "Click Me";
lb.Click += lb_Click;
ph.Controls.Add(lb);
ph.DataBind();
}
void lb_Click(object sender, EventArgs e)
{
lblMessage.Text = "Button is clicked!";
}
}