VB Like InputBox for MFC

• Download demo project - 18.9 Kb
• Download source - 2.82 Kb

Introduction

I have been developing softwares both in VB & VC, and like many of you, wanted to get user input using something like VB's InputBox. For this, I searched at CodeProject and found some solutions (thanx to them). The problem was: all of them used some dialog resources to solve the problem that ultimately increases the size of the application.

Solution

I am presenting the InputBox by sub-classing the MessageBox provided by MFC. Last week, I found the "Do not ask again" MessageBoxes by Nicolas Bonamy; that discusses the sub-classing of MessageBox to create a CheckBox. I used the same idea to present an EditBox to get the user input by popping the MessageBox. Thanx Nic for the idea.

Sub-classing MessageBox

This relies on MFC hooking through the AfxHookWindowCreate() function. With this, we redirect the MessageBox messages to us and therefore are able to catch (once more) WM_INITDIALOG. Here, we resize the window, add the EditBox and so on...

The big advantage is that our class is in a way the MessageBox itself with an added functionality of Edit Control; and hence the events from Edit control are handled in our class.

Using the code

To use the CInputBox, simply:

• Add the InpuBox.h & InputBox.cpp to your project
• Instantiate the CInputBox object
• Call the Show method with a string.
• When the call to Show() returns, the provided string will contain the user input.

//
CInputBox theInputBox(this);
CString strUserInput;
theInputBox.Show("Please Enter Some Text Here...", strUserInput);

  MessageBox(strUserInput);

Enhancement/Extension

I think you can further enhance the class by setting some methods to implement your specific needs like:

• Only Numeric set ES_NUMBER
• Special characters by catching EN_CHANGE
• More than one Edits for different inputs.

Credits

My sincere thanx to:

• Nicolas Bonamy: whose code inspired me for doing such an implementation.
• My friend Sadiq: who always helps me whenever I am stuck in problems.
• My brother Ubaid: who helped me in writing & discussing the code.
• Most of all, my "teacher" MSDN: you know most of us are nothing without it.