HOWTO: Set an Error Level from a Visual Basic Application

• Microsoft Visual Basic Professional and Enterprise Editions for Windows, versions 4.0, 5.0, 60

SUMMARY

This article contains a sample Visual Basic application that sets the error level upon exiting and a DOS batch file to test the result. Visual Basic applications can also retrieve the error level returned by another Windows application using the technique shown in Q129796 listed below.

MORE INFORMATION

Steps to Reproduce Behavior

1. Create a new Standard EXE project. Form1 is created by default.



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



3. Add the following code to the General Declarations section of Form1:
   

   
         Private Declare Sub ExitProcess Lib "kernel32" _
         (ByVal uExitCode As Long)
   
         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
   
         Private Sub Form_Load()
            Command1.Caption = "50"
            Command2.Caption = "100"
            Command3.Caption = "150"
         End Sub
    




4. Save your Project and Make an executable named Project1.EXE.



5. 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
    




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

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



• "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."



• In order to retrieve the error level from a Visual Basic Program instead of a DOS Batch file:
  
  
  • Implement Knowledge Base article Q129796. Modify the call to ExecCmd function in the Form_Click event to pass "project1.exe" instead of "notepad.exe". Run the project and click on form1 to launch project1.exe.
  
  
  

REFERENCES

Q129796 : HOWTO: 32-Bit App Can Determine When a Shelled Process Ends

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