绑定XAML属性可视性视图模型，与按钮

Question

我在XmaI位一个StackLayout属性控制如下所示：

<StackLayout x:Name="_infoView" 
       Margin="0,10,0,10" 
       BackgroundColor="Black" 
       IsVisible="{Binding State}"/> 

和在视图模型的结合布尔变量

private Boolean _state = true; 
    public Boolean State 
    { 
     get { return _state; } 
     set { } 
    } 

我有一个按钮我的XMAL，并希望控制我的StackLayout的知名度，所以我做了这样的事情：

 <Button x:Name="CloseButton" 
       Grid.Row="0" 
       Grid.Column="3" 
       Command="{Binding CloseWindowCommand}"/> 

和视图模型

CloseWindowCommand = new Command(CloseWindowTapped, CanCloseWindowTapped); 

public ICommand CloseWindowCommand { get; set; } 
public void CloseWindowTapped() 
{ 
    State = false; 
} 
public bool CanCloseWindowTapped() 
{ 
    return true; 
} 

我认为，通过在CloseButton水龙头，我StackLayout将消失...但它不工作

Answer 1

视图模型应该实现INotifyPropertyChanged接口用于通知更改视图。

public class ViewModel : INotifyPropertyChanged 
{ 
    // Implementing INotifyPropertyChanged 
    public event PropertyChangedEventHandler PropertyChanged; 

    protected void RaisePropertyChanged([CallerMemberName]string propertyName = null) 
    { 
     PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName); 
    }   

    // In the setter of property raise event to inform view about changes 
    private Boolean _state = true; 
    public Boolean State 
    { 
     get 
     { 
      return _state; 
     } 
     set 
     { 
      _state = value; 
      RaisePropertyChanged(); 
     } 
    } 
}