writing text to response not working when exception is thrown

Question

I am trying to write some text before the line is throwing the exception, I want to view that text written by response, anyway I cannot see that, but only the exception is shown, Where can I find that text now.. The code below may give a clear picture.

res.Write(col1);
res.Write(colms);
String colName = colms[col1];

Now i am getting this exception at the third line:

Index was out of range. Must be non-negative and less than the size of the collection. Parameter name: index

I want to see those values as shown in code, but that is not working. In Java I used to do something like

System.out.println(col1);

and that will print to the netbeans console. Now i am using VS2010. How to achieve that same here?

Answer 1

您可以使用Debug.Print打印到附加的调试侦听器（大概是VS）：

System.Diagnostics.Debug.Print(col1.ToString());

Answer 2

You asked about the following error

Index was out of range. Must be non-negative and less than the size of the collection. Parameter name: index

Problem can be

 String colName = colms[col1];

Index out of range means you are trying to access an index which is not in the range.

Edit 1

You can put break point to see what values are coming in your variable.
Here is good link about break points
http://weblogs.asp.net/scottgu/archive/2010/04/21/vs-2010-debugger-improvements-breakpoints-datatips-import-export.aspx

Edit 2

You can also take benefit of immediate window.

How do you use the Immediate Window in Visual Studio?

Answer 3

将代码放在try块中，就可以访问catch块中的col1。