Why IE does not refresh the page after a JS call to a click button?
On a ASP.Net page, I am in front of a problem only with IE. Here is the description.
On a page, there is two buttons a开发者_Python百科nd one label. The first button is visible and calls a JS function on the click event. This JS function calls the click function of the second button. The second button has an C€ event handler on the click event. The C# event handler edit the label.
In Firefox : the label is correctly edited after the clicks. In IE (8) : the label is not edited, despite the C€ event handler has been correctly hit.
Also, I observed, in IE, that the Page_Load event is called two times after the JS button click : Page_Load button2_OnClick => change of the Label Text Page_Load => The Label Text is reset :(
In Firefox, the Page_Load is called only once.
My question is : how to make IE refresh correctly the page as Firefox does after a JS button click ?
Below is the sample test code :
1) Page ASPX
<head runat="server">
<title></title>
<script type="text/javascript">
function button1Click(sender, args) {
var button2 = document.getElementById("button2");
button2.click();
}
</script>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:Button runat="server" ID="button1" Text="Click-me!" OnClientClick="button1Click();" />
<asp:Button runat="server" ID="button2" Text="Second" OnClick="button2_OnClick" style="display:none" />
<p />
<asp:Label runat="server" ID="label1" Text="Init" />
</div>
</form>
</body>
</html>
2) C# code-behind :
public partial class _Default : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
protected void button2_OnClick(object sender, EventArgs e)
{
label1.Text = "Changed";
}
}
The ID of your button will not be button1 or button2 when it's rendered. It will probably be something like ctl001_button1. Therefore your javascript will not work. In ASP.NET 4 you can override this behaviour by using an assigned ClientID.
<asp:Button runat="server" ID="button1" Text="Click-me!"
OnClientClick="button1Click();" ClientIDMode="Static" />
<asp:Button runat="server" ID="button2" Text="Second"
OnClick="button2_OnClick" style="display:none" ClientIDMode="Static" />
As an aside, this alludes to the main problem with ASP.NET Winforms - it tricks developers into thinking that the web is a connected environment.
What actually happens when you click an <asp:Button /> element by default is that a postback is invoked. I.e. Your browser sends a request to the server for a new page. It sends up something called ViewState which is how the server knows what you've done and what to render. There is no "event" handled as such.
I think the problem is with the way you are trying to get the hidden button
var button2 = document.getElementById("button2");
maybe change this to
var button2 = document.getElementById("<%= button2.ClientID %>");
After the buttons are rendered in the browser, the ID is changed by the ASP.Net engine, and not the same as your source.
http://msdn.microsoft.com/en-us/library/system.web.ui.control.clientid.aspx
Hope this helps.
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