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Correctly restore mouse cursor

Correctly restore mouse cursor

When you write lengthy procedures, it is a good habit to change the mouse cursor to an hourglass, and restore it to the original shape when the procedure exits. However, this cursor tracking may be rather difficult when the procedure has multiple exit points, or when it can exit abruptly because of an unanticipated error. An alternative, better approach is to use a very simple class that changes the mouse cursor to your desired shape, and automatically restores it when the object reference is destroyed:

' the CMouseCursor classPrivate oldMousePointer As Variant' enforce a new cursorSub SetCursor(Optional NewCursor As MousePointerConstants = vbHourGlass)    If IsEmpty(oldMousePointer) Then        ' save the original cursor, but only the first        ' time this method is invoked in this instance        oldMousePointer = Screen.MousePointer    End If    Screen.MousePointer = NewCursorEnd SubPrivate Sub Class_Terminate()    ' restore original mouse cursor, if it changed    If Not IsEmpty(oldMousePointer) Then        Screen.MousePointer = oldMousePointer    End IfEnd Sub

Note that the class stores the mouse cursor only the first time the SetCursor is invoked; if you omit any argument when calling the method, the cursor is changed to an hourglass. Here is an example of how this class can be used:

Sub MyRoutine()    Dim mouse As New CMouseCursor    ' save current cursor, enforce a new one    mouse.SetCursor vbArrowQuestion    ' ...    ' change to an hourglass    mouse.SetCursor    ' ...    ' the original mouse cursor is automatically    ' restored when this procedure is exitedEnd Sub

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