How to prevent button click 2 times in update panel?

I have a button which is in update panel. When I click on button then it click event run two times. How can I pre开发者_开发知识库vent second time click event?

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I had the same problem.

I had an "onclick=swap_img" in the aspx code and the following in the vb code so it ran twice. I just removed the onclick in the aspx code:

Protected Sub swap_img(sender As Object, e As System.Web.UI.ImageClickEventArgs) Handles btn_img.Click

This article helped me figure this problem out: http://forums.asp.net/t/1056418.aspx

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Check if you did not attach the handler function twice to the click event (for example once by html/javascript and once in the vb code).

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Why not disable the button at the start of the button callback function...

Then, using something sensible like a try/finally block, enable the button at the end, in the finally.

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On Page load, you can use:

button.Attributes.Add("onClick", "<< javascript >>")

... to attach some javascript to the Click event of the button.

You can find javascript to disable the button with a simple Google search.