MS Project VBA - 当过滤器不返回任何内容时如何避免错误

Question

我的代码将过滤器应用于项目（仅显示下周特定资源的活动），我需要捕获过滤器不返回任何内容的实例。

我找到了这个article，它导致了这个MS Entry。从这里我想出了测试：

If ActiveSelection.Tasks Is Nothing Then GoTo NextResource

退出当前资源循环并转到下一个，但是，这不起作用。错误 (424) 仅在我尝试使用 ActiveSelection 时生成

上下文的代码片段：

For Each Resource In Proj.Resources
    If Not (Resource Is Nothing) Then
    If Resource.Work > 0 Then
     'setup and apply filter for each resource
     FilterEdit name:="filter4people", TaskFilter:=True, Create:=True, OverwriteExisting:=True, FieldName:="Start", Test:="is less than or equal to", Value:=finish, ShowInMenu:=True, ShowSummaryTasks:=True
     FilterEdit name:="filter4people", TaskFilter:=True, FieldName:="", NewFieldName:="% Complete", Test:="is less than", Value:="100%", Operation:="And", ShowSummaryTasks:=True
     FilterEdit name:="filter4people", TaskFilter:=True, FieldName:="", NewFieldName:="Resource names", Test:="contains", Value:=Resource.name, Operation:="And", ShowSummaryTasks:=True
         
     FilterApply "filter4people" ' apply the filter
        If Not (Err.Number = 91 Or Err.Number = 0) Then            ' saw an error applying filter
             Err.Clear                   ' clear out the error
             GoTo NextResource           ' jump to the next resource
         End If

    Application.SelectSheet 'need to select the sheet so that ActiveSelection works properly
    
    'CStr(ActiveSelection.Tasks.Count)
    If ActiveSelection.Tasks Is Nothing Then GoTo NextResource

Answer 1

您的问题是 ActiveSelection 对象无法解析 .Tasks 属性，如果没有任务符合所应用过滤器的条件。我不喜欢将 GoTos 用于不是 VBA 中的错误处理程序的任何内容，因此我建议创建一个单独的函数来检查过滤器中是否有任何任务：

Public Function CurrentFilterHasTasks() As Boolean

   Dim result As Boolean
   On Error GoTo ErrHandler

   Application.SelectAll 'select everything in the current filter

   'Application.ActiveSelection.Tasks will fail if there are only blank rows in the active selection
   If Application.ActiveSelection.Tasks.Count > 0 Then
        result = True
   End If

   CurrentFilterHasTasks = result

   'call exit function here so the code below the error handler does not run
   Exit Function

ErrHandler:
   result = False
   CurrentFilterHasTasks = result
    
End Function

现在你可以在你的代码中调用这个函数了：

For Each Resource In Proj.Resources
    If Not (Resource Is Nothing) Then
        If Resource.Work > 0 Then
         'setup and apply filter for each resource
         FilterEdit Name:="filter4people", TaskFilter:=True, Create:=True, OverwriteExisting:=True, FieldName:="Start", test:="is less than or equal to", Value:=Finish, ShowInMenu:=True, ShowSummaryTasks:=True
         FilterEdit Name:="filter4people", TaskFilter:=True, FieldName:="", NewFieldName:="% Complete", test:="is less than", Value:="100%", Operation:="And", ShowSummaryTasks:=True
         FilterEdit Name:="filter4people", TaskFilter:=True, FieldName:="", NewFieldName:="Resource names", test:="contains", Value:=Resource.Name, Operation:="And", ShowSummaryTasks:=True
             
         FilterApply "filter4people" ' apply the filter
         
         If Not (Err.Number = 91 Or Err.Number = 0) Then ' saw an error applying filter
             Err.Clear                   ' clear out the error
             GoTo NextResource           ' jump to the next resource
         End If
        
        ''''' Calling the new function ''''''
        If CurrentFilterHasTasks Then
            'whatever you want to do with the filtered tasks here
        End If

此外，我可能会卸载您的代码以创建过滤器并将其应用到它自己的方法中，这样您就可以检查其中的任何错误，而不是您的主要方法。