当结构中的关联元素更改其值时,用新值更新WPF文本框

时间:2018-07-07 08:59:00

标签: wpf vb.net xaml events

当用户单击从随机访问文件中检索新数据的WPF按钮时,值的结构确实发生变化。 可以同时执行CanExecute和Execute方法。

Q#1: 子执行和属性中需要什么,以使文本框反映结构中的新值?

Q#2: 在程序中如何确定CanExecute应该返回true还是false?

XAML:

<Button Grid.Column="2" Grid.Row="0"  Command="{Binding}" 
 Click="Button_Click" Content="Get Record"/> 

VB.NET:

Structure myStruct
    Implements ICommand
    Implements INotifyPropertyChanged
    Public Event CanExecuteChanged As EventHandler Implements ICommand.CanExecuteChanged
    Public Event PropertyChanged As PropertyChangedEventHandler Implements INotifyPropertyChanged.PropertyChanged

    Public _element As Integer

    Public Property Element As Integer
        Get
            Return _element
        End Get
        Set(value As Integer)
            _element = value
        End Set
    End Property

    Public Function CanExecute(parameter As Object) As Boolean Implements ICommand.CanExecute
        'Throw New NotImplementedException()
        'CanExecute = True
        MsgBox("CanExecute") 
    End Function

    Public Sub Execute(parameter As Object) Implements ICommand.Execute
        'Throw New NotImplementedException()
        MsgBox("Execute")
    End Sub

End Structure

0 个答案:

没有答案