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I would like to call a javascript function from an aspx control. For instance, suppose I had:
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>Untitled Page</title>
<script type="text/javascript">
function test(x, y)
{
}
</script>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:Button ID="Button1" runat="server" Text="Button"
onclick="Button1_Click"/>
</div>
</form>
</body>
</html>
and in the code behind:
protected void Button1_Click(object sender, EventArgs e)
{
// do stuff (really going to a database to fill x and y)
int[] x = new int[] { 1, 2, 3, 4, 5 };
int[] y = new int[] { 1, 2, 3, 4, 5 };
// call javascript function as test(x,y);
}
Is there a way to do it?
878
You can use the Page.ClientScript.RegisterStartupScript method.
110
Look at the ScriptManager.RegisterStartupScript method if you're using a ScriptManager or any Ajax controls/asynchronous postbacks.
Edit:
Actually, the function you want is probably ScriptManager.RegisterClientScriptBlock
35
Some other things I found out:
You can't directly pass in an array like:
this.Page.ClientScript.RegisterClientScriptBlock(this.GetType(), "xx",
"<script>test("+x+","+y+");</script>");
because that calls the ToString() methods of x and y, which returns "System.Int32[]", and obviously Javascript can't use that. I had to pass in the arrays as strings, like "[1,2,3,4,5]", so I wrote a helper method to do the conversion.
Also, there is a difference between this.Page.ClientScript.RegisterStartupScript() and this.Page.ClientScript.RegisterClientScriptBlock() - the former places the script at the bottom of the page, which I need in order to be able to access the controls (like with document.getElementByID). RegisterClientScriptBlock() is executed before the tags are rendered, so I actually get a Javascript error if I use that method.
http://www.wrox.com/WileyCDA/Section/Manipulating-ASP-NET-Pages-and-Server-Controls-with-JavaScript.id-310803.html covers the difference between the two pretty well.
Here's the complete example I came up with:
// code behind
protected void Button1_Click(object sender, EventArgs e)
{
int[] x = new int[] { 1, 2, 3, 4, 5 };
int[] y = new int[] { 1, 2, 3, 4, 5 };
string xStr = getArrayString(x); // converts {1,2,3,4,5} to [1,2,3,4,5]
string yStr = getArrayString(y);
string script = String.Format("test({0},{1})", xStr, yStr);
this.Page.ClientScript.RegisterStartupScript(this.GetType(),
"testFunction", script, true);
//this.Page.ClientScript.RegisterClientScriptBlock(this.GetType(),
//"testFunction", script, true); // different result
}
private string getArrayString(int[] array)
{
StringBuilder sb = new StringBuilder();
for (int i = 0; i < array.Length; i++)
{
sb.Append(array[i] + ",");
}
string arrayStr = string.Format("[{0}]", sb.ToString().TrimEnd(','));
return arrayStr;
}
//aspx page
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>Untitled Page</title>
<script type="text/javascript">
function test(x, y)
{
var text1 = document.getElementById("text1")
for(var i = 0; i<x.length; i++)
{
text1.innerText += x[i]; // prints 12345
}
text1.innerText += "\ny: " + y; // prints y: 1,2,3,4,5
}
</script>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:Button ID="Button1" runat="server" Text="Button"
onclick="Button1_Click" />
</div>
<div id ="text1">
</div>
</form>
</body>
</html>
include script manager
code behind function
ScriptManager.RegisterStartupScript(this, this.GetType(), "HideConfirmBox", "javascript:HideAAConfirmBox(); ", true);
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