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How can I call a javascript function from server side

I try to call a javascript function from an other c# function but I have an error in my console
Uncaught ReferenceError: updateState is not defined
.ascx file
<script>
function updateState(){
console.log("test")
}
</script>
<button runat="server" ID="Btn_Modify_state" onserverclick="Btn_Modify_state_Click">
<i class="fas fa-edit"></i>
</button>
.ascx.cs file
protected void Btn_Modify_state_Click(object sender, EventArgs e)
{
ScriptManager.RegisterClientScriptBlock(this, this.GetType(), "script", "updateState();", true);
}
I don't know how to resolve that issue someone have any idea ?

You may have forgotten to register the script. Try this different approach instead.
<script runat="server">
public void Page_Load(Object sender, EventArgs e)
{
// Define the name and type of the client script on the page.
String csName = "updateState";
Type csType = this.GetType();
// Get a ClientScriptManager reference from the Page class.
ClientScriptManager cs = Page.ClientScript;
// Check to see if the client script is already registered.
if (!cs.IsClientScriptBlockRegistered(csType, csName))
{
// If not, redefine your script
var csText = $"
<script type=\"text/javascript\">
function updateState(){
console.log("test")
}
</script>";
cs.RegisterClientScriptBlock(csType, csName, csText.ToString());
}
}
</script>
Source : https://learn.microsoft.com/en-us/dotnet/api/system.web.ui.clientscriptmanager.registerclientscriptblock?view=netframework-4.8

The solution was to do that :
.ascx.cs
protected void Btn_Modify_state_Click(object sender, EventArgs e)
{
Page.ClientScript.RegisterStartupScript(this.GetType(), "script", "<script type='text/javascript'>updateState();</script>");
}

window.returnValue rework for chrome

I have a java date picker and it is not passing back the value in chrome. I think its is due to the js using window.returnvalue. How would i fix this?
// Allow the browser to save/pass the date selected and close the window.
protected void calDate_SelectionChanged(object sender, System.EventArgs e)
{
string closeWindow = #"
<script language='javascript'>
window.returnValue='###date###';
window.close();
</script>";
closeWindow = closeWindow.Replace("###date###", calDate.SelectedDate.ToShortDateString());
ClientScript.RegisterStartupScript(this.GetType(), "CloseWindow", closeWindow);
}

Call Javascript function multiple times from code behind

I have the following button event handler in C#. I would like to call the same javascript function with different paramater.
protected void Button1_Click(object sender, EventArgs e)
{
for (int i = 0; i < 10; i++)
{
string script = String.Format("test({0},{1})", i.ToString(), i.ToString() + 1);
this.Page.ClientScript.RegisterStartupScript(this.GetType(),
"testFunction", script, true);
}
}

define your js method like:
<script type="text/javascript">
function UpdateTime(time) {
document.getElementById("<%=lblTime.ClientID %>").innerHTML = time;
}
and then in your code behind, use:
protected void UpdateTime(object sender, EventArgs e)
{
string time = DateTime.Now.ToString("hh:mm:ss tt");
string script = "window.onload = function() { UpdateTime('" + time + "'); };";
ClientScript.RegisterStartupScript(this.GetType(), "UpdateTime", script, true);
}
Source and demo here

How to pass String Argument to javascript function

This is my front-end:
ImageButton Details = (ImageButton)e.Row.FindControl("iBtnDetails");//take lable id
String strApplication1 = Details.CommandArgument.ToString();
e.Row.Attributes["onmouseover"] = "this.style.cursor='hand';this.style.textDecoration='underline';";
e.Row.Attributes["onmouseout"] = "this.style.textDecoration='none';";
e.Row.Attributes.Add("onClick", "SelectRow()");
This is my back-end:
<script type="text/javascript">
function SelectRow() {
var strApplication1 = '<%=strApplication1%>'
if (strApplication1 == "IT Application Request")
{
window.open('http://.aspx', '_blank');
}
else if (strApplication1 == "IT Account Request")
{
window.open('http://.aspx', '_blank');
}
else if (strApplication1 == "Change Control Management")
{
window.open('http://.aspx', '_blank');
}
else if (strApplication1 == "Backup & Restore")
{
window.open('http://.aspx', '_blank');
}
}
</script>
I want to pass String Argument to javascript function, but I got error that strApplication1 doesn't exist in the current context.

You need to make strApplication1 a public property on your page class. Currently, it is just an internal variable.
Something like:
public partial class YourPage : System.Web.UI.Page
{
public string strApplication1 {get; set;}
protected void Page_Load(object sender, EventArgs e)
{
//Your page logic
}
//Looks like you set the variable in an onDatabound or similar.
//So use this where you currently set the variable
strApplication1 = Details.CommandArgument.ToString();
}

Get Javascript Variable Value in Server Side Without Page Load

I am trying to get value of Javascript variable
on server side, but it always shows values on
second button click and I don't want to reload this page again
protected void Button1_Click(object sender, EventArgs e)
{
Page.ClientScript.RegisterStartupScript(Page.GetType(), "MessageBox", "<script language='javascript'>setValues();</script>");
Thread.Sleep(5000);
Response.Write(HiddenField1.Value);
}
Javascript Code . . . ..
<script type="text/javascript">
function setValues()
{
var abc = "thi is first";
document.getElementById('<%=HiddenField1.ClientID%>').value = abc;
}
</script>