Question

我有这个子程序来打开/关闭class _Countdown extends State<Countdown> { int val = 3; void countdown(){ CountDown cd = new CountDown(new Duration(seconds: 4)); cd.stream.listen((Duration d) { setState((){ val = d.inSeconds; }); }); } @override build(BuildContext context){ countdown(); return new Scaffold( body: new Container( child: new Center( child: new Text(val.toString(), style: new TextStyle(fontSize: 150.0)), ), ), ); } }的一些属性。

Application

假设有一个不同的应用程序实例我希望打开/关闭相同的属性，我如何能够修改此代码以接受参数/参数作为不同的应用程序？我期待着类似的东西;

Public Sub OPTIMIZE_VBA(ByVal isOn As Boolean)
Dim bHolder As Boolean
bHolder = Not isOn
On Error Resume Next
With Application
  .DisplayAlerts = bHolder
  .ScreenUpdating = bHolder
  .EnableEvents = bHolder
  .Calculation = IIf(isOn, xlCalculationManual, xlCalculationAutomatic)
  .Calculate
    If .VERSION > 12 Then .PrintCommunication = bHolder
End With
On Error GoTo 0
End Sub

有了这个，我可以称之为;

Public Sub OPTIMIZE_VBA(ByVal isOn As Boolean, Optional ByVal ExApp As Excel.Application = thisApplication)
' rest of the code
End Sub

Answer 1

一种方式：

Public Sub OPTIMIZE_VBA(ByVal isOn As Boolean, Optional ByVal ExApp As Excel.Application = Nothing)

    If ExApp Is Nothing Then Set ExApp = Application
    ' rest of the code

End Sub

Answer 2

Public Sub OPTIMIZE_VBA(ByVal isOn As Boolean, Optional ByVal ExApp As Excel.Application)

If IsEmpty(ExApp) Or ExApp Is Nothing Then
    Set ExApp = Application
End If

' rest of the code
End Sub

Sub参数声明为Application类型变量

2 个答案: