How to use Console.WriteLine in ASP.NET (C#) during debug?

Question

I want to write some result to the console in ASP.NET (C#). It works in a Window application, but a Web application does not work. Here is what I have tried:

Answer 1

Use response.write method in the code-behind.

Answer 2

Make sure you start your application in Debug mode (F5), not without debugging (Ctrl+F5) and then select "Show output from: Debug" in the Output panel in Visual Studio.

Answer 3

If for whatever reason you'd like to catch the output of Console.WriteLine, you CAN do this:

protected void Application_Start(object sender, EventArgs e)
{
    var writer = new LogWriter();
    Console.SetOut(writer);
}

public class LogWriter : TextWriter
{
    public override void WriteLine(string value)
    {
        //do whatever with value
    }

    public override Encoding Encoding
    {
        get { return Encoding.Default; }
    }
}

Answer 4

Trace.Write("Error Message") and Trace.Warn("Error Message") are the methods to use in web, need to decorate the page header trace=true and in config file to hide the error message text to go to end-user and so as to stay in iis itself for programmer debug.

Answer 5

using System.Diagnostics;

The following will print to your output as long as the dropdown is set to 'Debug' as shown below.

Debug.WriteLine("Hello, world!");

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Answer 6

You shouldn't launch as an IIS server. check your launch setting, make sure it switched to your project name( change this name in your launchSettings.json file ), not the IIS.