[c#] Passing arguments to JavaScript function from code-behind

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>

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