в 16:33, 26 мая 2010

2010-05-26T16:33:00Z

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2010-05-26T12:46:32Z

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==An Example of Code Without Error Handling==



<source lang="vb">

Sub cmdNoErrorHandler()
Call TestError1(1, 0)
End Sub
Sub TestError1(Numerator As Integer, Denominator As Integer)
Debug.Print Numerator / Denominator
msgBox "I am in Test Error"
End Sub
</source>

==An Example of Error Handling Using the On Error GoTo Statement==



<source lang="vb">

Sub SimpleErrorHandler()
On Error GoTo SimpleErrorHandler_Err
Dim sngResult As Single
sngResult = 1 / 0
Exit Sub
SimpleErrorHandler_Err:
msgBox "Oops!"
Exit Sub
End Sub
</source>

==A Simple Error-Handling Routine==



<source lang="vb">

Sub TestError2()
On Error GoTo TestError2_Err
Debug.Print 1 / 0
msgBox "I am in Test Error"
Exit Sub
TestError2_Err:
If Err = 11 Then
msgBox "Variable 2 Cannot Be a Zero", , "Custom Error Handler"
End If
Exit Sub
End Sub
</source>

==EBEngine.Errors==



<source lang="vb">

Public Sub ShowErrors()
Dim db As Database
Dim recT As Recordset
Dim errE As Error

On Error GoTo ShowErrors_Err

Set db = CurrentDb()
Set recT = db.OpenRecordset("NonExistantTable")
recT.Close

ShowErrors_Exit:
Exit Sub

ShowErrors_Err:
Debug.Print "Err = " & Err.Number & ": " & Err.Description
Debug.Print

For Each errE In DBEngine.Errors
Debug.Print "Errors: " & errE.Number & ": " & errE.Description
Next
Resume ShowErrors_Exit

End Sub
</source>

==error handling by checking the Error code==



<source lang="vb">

Public Sub ErrorHandling()
On Error GoTo ErrorHandling_Err
Dim dblResult As Double
dblResult = 10 / InputBox("Enter a number:")
MsgBox "The result is " & dblResult
ErrorHandling_Exit:
Exit Sub
ErrorHandling_Err:
Select Case Err.Number
Case 13 " Type mismatch - empty entry
Resume
Case 11 " Division by 0
dblResult = 0
Resume Next
Case Else
MsgBox "Oops: " & Err.Description & " - " & Err.Number
Resume ErrorHandling_Exit
End Select
End Sub
</source>

==Ignoring an Error and Continuing Execution==



<source lang="vb">

Sub TestResumeNext()
On Error Resume Next
Kill "AnyFile"
If Err.number = 0 Then
Else
MsgBox "the Error Was: " & Err.Description
End If
End Sub
</source>

==Looking Up the Call Stack for a Previous Error Handler==



<source lang="vb">

Sub Func1()
On Error GoTo Func1_Err
Debug.Print "I am in Function 1"
Call Func2
Debug.Print "I am back in Function 1"
Exit Sub
Func1_Err:
msgBox "Error in Func1"
Resume Next
End Sub
Sub Func2()
Debug.Print "I am in Func2"
Call Func3
Debug.Print "I am still in Func2"
End Sub
Sub Func3()
Dim sngAnswer As Single
Debug.Print "I am in Func3"
sngAnswer = 5 / 0
Debug.Print "I am still in Func3"
End Sub
</source>

==Placing a Resume Next Statement in Your Error Handler==



<source lang="vb">

Sub TestResumeNextInError()
On Error GoTo TestResumeNextInError_Err
Kill "AnyFile"
If Err.number = 0 Then
Else
msgBox "We Didn"t Die, But the Error Was: " & Err.Description
End If
Exit Sub
TestResumeNextInError_Err:
Resume Next
End Sub
</source>

==Read user choice when dealing with error==



<source lang="vb">

Public Sub ErrorTrap1()
Dim Answer As Long, MyFile As String
Dim Message As String, CurrentPath As String

On Error GoTo errTrap
CurrentPath = CurDir$

ChDrive "A"
ChDrive CurrentPath
ChDir CurrentPath
MyFile = "A:\Data.xls"
Application.DisplayAlerts = False
ActiveWorkbook.SaveAs Filename:=MyFile
TidyUp:
ChDrive CurrentPath
ChDir CurrentPath
Exit Sub
errTrap:
Message = "Error No: = " & Err.Number & vbCr
Message = Message & Err.Description & vbCr & vbCr
Message = Message & "Please place a disk in the A: drive" & vbCr
Message = Message & "and press OK" & vbCr & vbCr
Message = Message & "Or press Cancel to abort File Save"
Answer = MsgBox(Message, vbQuestion + vbOKCancel, "Error")
If Answer = vbCancel Then Resume TidyUp
Resume
End Sub
</source>

==Using Resume Conditionally Based on User Feedback==



<source lang="vb">

Function GoodResume()
On Error GoTo GoodResume_Err
Dim strFile As String
strFile = Dir(strFileName)
If strFile = "" Then
GoodResume = False
Else
GoodResume = True
End If
Exit Function
GoodResume_Err:
Dim intAnswer As Integer
intAnswer = MsgBox(Error & ", Would You Like to Try Again?", vbYesNo)
If intAnswer = vbYes Then
Resume
Else
Exit Function
End If
End Function
</source>

==Using the Resume <LineLabel> Statement to Specify Where Execution Continues After an Error Occurs==



<source lang="vb">

Sub TestResumeLineLabel()
On Error GoTo TestResumeLineLabel_Err
Dim sngResult As Single
sngResult = 1 / 0
TestResumeLineLabel_Exit:
Exit Sub
TestResumeLineLabel_Err:
msgBox "Error #" & Err.number & ": " & Err.Description
Resume TestResumeLineLabel_Exit
End Sub
</source>

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в 16:33, 26 мая 2010

Admin: 1 версия