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?

score 6 · Accepted Answer · answered Oct 14 '10 at 07:24

6

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>");

answered Oct 14 '10 at 07:24

Darin Dimitrov

1,023,142
271
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2,928

Used this in a classic asp to do something similar and it worked for me as well. Many Thanks! – James Drinkard Jan 07 '15 at 20:48

score 2 · Answer 2 · answered Oct 14 '10 at 07:23

2

Try something like

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

Have a look at the class Exception Class

answered Oct 14 '10 at 07:23

Adriaan Stander

162,879
31
289
284

2

The message should be HtmlEncoded. it could contain " or other charaters that will make the html rendering behave different from the intent – Rune FS Oct 14 '10 at 07:59

score 1 · Answer 3 · answered Jul 25 '14 at 12:16

1

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

answered Jul 25 '14 at 12:16

Jayashree Saravanan

11
1

score 0 · Answer 4 · edited Jul 25 '14 at 12:40

0

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);

edited Jul 25 '14 at 12:40

Atur

1,712
6
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answered Oct 02 '13 at 09:29

rehu

11
2

score 0 · Answer 5 · answered Oct 14 '10 at 07:37

0

Please check whthr you r using update panel in that page.It may sometimes work if the update panel is there.

answered Oct 14 '10 at 07:37

kbvishnu

14,760
19
71
101

score 0 · Answer 6 · answered Oct 14 '10 at 07:38

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>");

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

6 Answers6