HOWTO: Set an Error Level from a Visual Basic Application

• Microsoft Visual Basic Professional and Enterprise Editions for Windows, versions 4.0, 5.0 on the following platforms: NT, Win95

SUMMARY

This article contains a sample Visual Basic application that sets the DOS error level upon exiting and a DOS batch file for testing.

MORE INFORMATION

1. Start a new project and save as Project1.

2. In the Declaration Section of Form1, add the following declaration:

         Private Declare Sub ExitProcess Lib "kernel32" _
         (ByVal uExitCode As Long)
   

3. Place three CommandButtons on the form (use default names).

4. Change the Caption property on the CommandButtons to 50, 100, and 150 respectively.

5. Place the following code behind the form:

         Private Sub Command1_Click()
            ExitProcess (50&) 'Button labeled "50"
         End Sub
      
         Private Sub Command2_Click()
            ExitProcess (100&) 'Button labeled "100"
         End Sub
      
         Private Sub Command3_Click()
            ExitProcess (150&) ''Button labeled "150"
         End Sub
   
   

6. Save the Project and Make the executable.

7. Create the following batch file named errlevel.bat in your project directory:

         echo off
         start /w project1
         rem "start /w"
         if errorlevel 150 goto 150
         if errorlevel 100 goto 100
         if errorlevel 50 goto 50
         echo Exit Code 0
         goto Done
         :150
         echo Exit Code 150
         goto done
         :100
         echo Exit Code 100
         goto done
         :50
         echo Exit Code 50
         :done
         echo done
   

8. Run the batch file. When the user clicks on a CommandButton, the application will terminate with the error level on the button. The batch file will then test the error level and echo the result to the screen.

1. Start /w is necessary for this to work correctly in Windows 95.

2. "if errorlevel" must be in the order presented. "If the EXIT status is less than the specified value, the specified DOS command is executed; otherwise, processing continues with the next batch file command."

REFERENCES

MS-DOS Batch Files, Second edition, MS Press

Keywords          : VB4WIN vb5all vb5howto
Version           : WINDOWS:4.0,5.0
Platform          : NT Win95 WINDOWS
Issue type        : kbhowto