我们如何从asp.net中的代码隐藏调用javascript函数？

Question

I have this javascript function :

function showLoader() {
           document.getElementById("loaderState").style.display = 'inline';
       }

And I have a button :

<asp:Button ID="btnSignUp" runat="server" Text="Sign Up" OnClick="btnSignUp_Click" />

I am tryong to call that js function in code behind :

protected void btnSignUp_Click(object sender, EventArgs e)
{
    try
    {
        int i = users.AddNewUser();
        if (i != 0)
        {
            Page.ClientScript.RegisterStartupScript(
                GetType(),
                "btnSignUp",
                "showLoader();",
                true);
        }
    }
    catch (Exception exp)
    {
        throw exp;
    }
}

But not worked!!! Why?
Thanks.

Answer 1

Use:

 ScriptManager.RegisterStartupScript(
 this,
 GetType(), 
"btnSignUp",
"showLoader();",
 true);

See these similar question:

ScriptManager.RegisterStartupScript code not working - why?

ClientScript.RegisterStartupScript not working

ScriptManager.RegisterStartUpScript(...) not working

Answer 2

Try This

protected void btnSignUp_Click(object sender, EventArgs e)
{
    try
    {
        int i = users.AddNewUser();
        if (i != 0)
        {
ScriptManager.RegisterStartupScript(this, GetType(), "btnSignUp", "showLoader()", true);

        }
    }
    catch (Exception exp)
    {
        throw exp;
    }
}