In c#, how can I check to see if a link button has been clicked in the page load method?
I need to know if it was clicked before the click event is fired.
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If your code is reliant on the OnClick event, then you can put that particular code in the OnPageRender override (rather than in Page_Load), as it will fire after the OnClick event handler.snumpy– snumpy2015-08-12 13:32:01 +00:00Commented Aug 12, 2015 at 13:32
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6 Answers
if( IsPostBack )
{
// get the target of the post-back, will be the name of the control
// that issued the post-back
string eTarget = Request.Params["__EVENTTARGET"].ToString();
}
2 Comments
Tsvetomir Tsonev
Did you test this? Should have two leading slashes - "__EVENTTARGET"
Thomas
Any ideas how this can be used with an Update Panel? It doesn't seem to work
if that doesn't work.Try UseSubmitBehavior="false"
Comments
The UniqueID of the button will be in Request.Form["__EVENTTARGET"]
Comments
Check the value of the request parameter __EVENTTARGET to see if it is the id of the link button in question.
Comments
Based on accepted answer and the answer of RealSteel this could be a more complete answer.
First add to the .aspx a button like this:
<asp:Button id="btnExport" runat="server" Text="Export" UseSubmitBehavior="false"/>
Then on the Page_Load method:
if(IsPostBack){
var eventTarget = Request.Params["__EVENTTARGET"]
// Then check for the id but keep in mind that the name could be
// something like ctl00$ContainerName$btnExport
// if the button was clicked or null so take precautions against null
// ... so it could be something like this
var buttonClicked = eventTarget.Substring(eventTarget.LastIndexOf("$") + 1).Equals("btnExport")
}
Comments
I just got the same trouble, have to do some logic judgement in the Page_Load method to treat different event(which button was clicked).
I realize the arm to get the as the following example.
The front end aspx source code(I have many Buttons with IDs F2, F3, F6, F12.
<Button Style="display: none" ID="F2" runat="server" Text="F2:Cancel" OnClientClick="SeiGyo(this)" OnClick="F2_Click" />
<Button Style="display: none" ID="F3" runat="server" Text="F3:Return" OnClientClick="SeiGyo(this)" OnClick="F3_Click" />
<Button Style="display: none" ID="F6" runat="server" Text="F6:Run" OnClientClick="SeiGyo(this)" OnClick="F6_Click" />
<Button Style="display: none" ID="F12" runat="server" Text="F12:Finish" OnClientClick="SeiGyo(this)" OnClick="F12_Click" />
The back end aspx.cs source code, what I need to do is judge which button was clicked when Page_Load was triggered. It seems a little stupid, but works. I hope that will be helpful to some others
Dictionary<string, string> dic = new Dictionary<string, string>();
foreach(var id in new string[]{"F2","F3","F6","F12"})
{
foreach (var key in Request.Params.AllKeys)
{
if (key != null && key.ToString().Contains(id))
dic.Add(id, Request[key.ToString()].ToString());
}
}
