World's Easiest Way to Reveal Control Names

Introduction

Is that textbox called txtFileName or txtFile? If you're like me, you have a bit of trouble remembering the names of various controls. This easy-to-implement routine will show you the name of any control in the title bar when you mouse over it.

Discussion

One of the first things I do in any project is to implement a way to reveal information to me when I am debugging an app. For instance, many of my error handlers include a call to a special routine that gives me all the dirty details of an error, much of which I want to spare the user from seeing. Another nice debugging extra is to show the name of each control so that I can remember what's what.

To do this, I first enable my custom debug mode. Then, as the app starts up, I run all of the controls through a subroutine that adds a handler to another subroutine that displays the control's name in the title bar.

Enable custom debug mode

The simplest way to do this is with a command line variable. In Visual Studio, click Project, Properties, Configuration Properties and add the command line variable you want. I'll use /d here. Then, add a global Boolean variable isDebug to your code and set it to True if you find the command line variable when you start the project:

Public isDebug as Boolean = False

Public Sub Main
     If Environment.CommandLine.IndexOf("/d")> -1 Then isDebug = True
.....
End Sub

Run controls through a subroutine

The subroutine is recursive--that is, it is likely to call itself. You start the chain of recursive calls by feeding it the name of the biggest control of all--your Form. Subsequent calls are made by the subroutine whenever it finds that the control it is working on has child controls. Here's the subroutine:

Private Sub AddHandlerForDebug(ctrlParent as Control)
  Dim ctrl as Control
  For Each ctrl in ctrlParent.Controls
     AddHandler ctrl.MouseEnter, AddressOf ShowControlName
     If ctrl.HasChildren Then AddHandlerForDebug(ctrl)
  Next
End Sub

Here's the subroutine that a MouseEnter event will trigger:

Private Sub ShowControlName(sender as System.Object, e as System.EventArgs)
     Me.Text = sender.Name
End Sub

Now all that is left is to go back to our Main subroutine and add a call to AddHandlerForDebug:

Public Sub Main
     If Environment.CommandLine.IndexOf("/d")>-1 Then isDebug = True

     If isDebug Then AddHandlerForDebug(Me)
.....
End Sub

You can get as fancy as you want in ShowControlName. For instance, I like to keep the "real" name of my app in the title bar and append the control name in curly braces. And with just a bit more work, you can even have the title bar show you the position of the control, its parent, or any other property.