Error while converting grid data to excel

Question

This is the code :

TextWriter writer = null;

HttpResponse response = new HttpResponse(writer);

response.ClearContent();
response.AddHeader("content-disposition", "attachment;filename=" + filename + ".xls");
// response.ContentType = "application/ms-excel";
StringWriter stringWriter = new StringWriter();
HtmlTextWriter htmlTextWriter = new HtmlTextWriter(stringWriter);
HtmlForm htmlForm = new HtmlForm();
GridView1.Parent.Controls.Add(htmlForm);
htmlForm.Attributes["runat"] = "server";
htmlForm.Controls.Add(GridView1);
htmlForm.RenderControl(htmlTextWriter);

response.Write(stringWriter.ToString());

If I run this code, it throws an NullReferenceException. I used this codes in a Business Logic Layer

Answer 1

You're getting a runtime error when you hit the response.Write line because you are passing null in as your stream for the response:

TextWriter writer = null;
HttpResponse response = new HttpResponse(writer);

The code you posted is very sloppy. I'd suggest you rewrite the method from scratch. If you don't you'll probably encounter other runtime errors once you get past this one.