Siebel VB Language Reference > Methods Reference for Siebel VB > Error Handling Methods >
On Error Method
The On Error method identifies the location of code that handles an error. It does not return a value. You can also use it to disable code that handles the error. If you do not use the On Error method, and if a run-time error occurs, then Siebel VB stops running code. Format
On Error {GoTo label | Resume Next | GoTo 0}
The following table describes that parts of an On Error statement. You can include only one of these parts.
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GoTo label |
Identifies the code that handles the error that starts at the label argument. If this label does not reside in the same procedure as the On Error statement, then Siebel VB creates an error message. |
Resume Next |
Identifies the code to run after handling the error. It typically identifies the code that occurs immediately after the statement that caused the error. You can use the Err statement to get the error code of the run-time error at this point in the error handling. |
GoTo 0 |
Disables any error handler that is enabled. |
Usage
Note the following:
- If an On Error GoTo label statement references an error handler, then that error handler is enabled.
- If an error handler is enabled, and if a run-time error occurs, then Siebel VB gives control to the code that includes this error handler. The error handler remains active from the time the run-time error is handled until code flow encounters a Resume statement in the error handler.
- If another error occurs while the error handler is active, then Siebel VB searches for the error handler in the procedure that called the current procedure:
- Running an End Sub or End Method statement while an error handler is active creates a No Resume error. You can use the Exit Sub or Exit Method statement to end the error condition and exit the current procedure.
Example
The following example prompts the user for a drive and directory name. It uses the On Error method to handle an entry that is not valid: Sub Button_Click Dim userdrive, userdir, msgtext in1: userdrive = "c:" On Error Resume Next ChDrive userdrive If Err = 68 then Goto in1 End If in2: On Error Goto Errhdlr1 userdir = "temp" ChDir userdrive & userdir userdir Exit Sub Errhdlr1: Select Case Err Case 75 msgtext = "Path is invalid." Case 76 msgtext = "Path not found." Case 70 msgtext = "Permission denied." Case Else msgtext = "Error " & Err & ": " & Error$ & "occurred." End Select Resume in2 End Sub
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