how to show exception variable value in alert box in asp.net using C#

Question

I have the following code, but the alert box is not displaying.

try
{
    do something..          
}
catch(Exception ex)
{
    Response.Write("<script>alert('"+ex+"')</script>");
}

If I use this code, the alert box appears.

try
{
    do some thing
}
catch (Exception ex)
{           
    Response.Write("<script>alert(\"an error occur\")</script>");
}

How can I display the exception variable in an alert box?

Answer 1

If you want to show the stacktrace:

Response.Write("<script>alert('"+ Server.HtmlEncode(ex.ToString()) + "')</script>");

or if you want only the message

Response.Write("<script>alert('"+ Server.HtmlEncode(ex.Message) + "')</script>");

Answer 2

Try something like

Response.Write("<script>alert('"+ex.Message+"')</script>"); 

Have a look at the class Exception Class

Answer 3

 Dim message = New JavaScriptSerializer().Serialize(rs)
 Dim script = String.Format("alert({0});", message)
 ScriptManager.RegisterClientScriptBlock(Page, Page.GetType(), "", Script, True)

Answer 4

This solved my problem:

  string jscriptCustInfo = "<script type='text/javascript' language='javascript'>";
  jscriptCustInfo = jscriptCustInfo + "alert('Dividend Posting Done, Batch No: "+lblBatch.Text+"');";

  jscriptCustInfo = jscriptCustInfo + "</script>";
  ScriptManager.RegisterClientScriptBlock(this.Page, this.GetType(), "", jscriptCustInfo, false);

Answer 5

请检查您在该页面中使用更新面板的情况。如果有更新面板，有时可能会有效。

Answer 6

You need to be careful and properly escape the Javascript string you are generating ... Imagine there are single quotes in the Exception's message ...

Single-quotes ( ' ) need to be escaped ( \\' )

Response.Write("<script>alert('"+ Server.HtmlEncode(ex.Message).Replace("'","\\'" ) + "')</script>");