Question

在初始值设置为true后，我对切换按钮的双向绑定将被分离。当我解开按钮时，它不再受约束。

我有两个切换按钮：

<RadioButton x:Name="BackupButton" Style="{StaticResource {x:Type ToggleButton}}" DataContext="{Binding BackupVM}" IsChecked="{Binding Mode=TwoWay, Path=IsViewVisible}">Backup</RadioButton>
<RadioButton x:Name="RestoreButton" Style="{StaticResource {x:Type ToggleButton}}">Restore</RadioButton>

我希望绑定到的BackupViewModel（实例化为BackupVM）中的属性：

private bool _IsViewVisible = true;
public bool IsViewVisible
{
        get { return _IsViewVisible; }
        set
        {
            if (value != _IsViewVisible)
            {
                _IsViewVisible = value;
                if (PropertyChanged != null)
                    PropertyChanged(this, new PropertyChangedEventArgs("IsViewVisible"));
            }
        }
    }

当切换一个时，我显示一个特定的用户控件（视图）并隐藏另一个。我需要做的是告诉我的基础视图模型隐藏视图，以便我可以停止刷新某些数据的计时器。在加载时设置IsChecked值后，由于某种原因绑定将被分离。以下是运行跟踪后的输出：

System.Windows.Data Warning: 52 : Created BindingExpression (hash=9343812) for Binding (hash=58368655)
System.Windows.Data Warning: 54 :   Path: 'IsViewVisible'
System.Windows.Data Warning: 57 : BindingExpression (hash=9343812): Default update trigger resolved to PropertyChanged
System.Windows.Data Warning: 58 : BindingExpression (hash=9343812): Attach to         System.Windows.Controls.RadioButton.IsChecked (hash=17818390)
System.Windows.Data Warning: 63 : BindingExpression (hash=9343812): Resolving source 
System.Windows.Data Warning: 66 : BindingExpression (hash=9343812): Found data context element: RadioButton (hash=17818390) (OK)
System.Windows.Data Warning: 74 : BindingExpression (hash=9343812): Activate with root item <null>
System.Windows.Data Warning: 102 : BindingExpression (hash=9343812):   Item at level 0 is null - no accessor
System.Windows.Data Warning: 76 : BindingExpression (hash=9343812): TransferValue - got raw value {DependencyProperty.UnsetValue}
System.Windows.Data Warning: 84 : BindingExpression (hash=9343812): TransferValue - using fallback/default value 'False'
System.Windows.Data Warning: 85 : BindingExpression (hash=9343812): TransferValue - using final value 'False'
System.Windows.Data Warning: 92 : BindingExpression (hash=9343812): Got PropertyChanged event from RadioButton (hash=17818390) for DataContext
System.Windows.Data Warning: 75 : BindingExpression (hash=9343812): Deactivate
System.Windows.Data Warning: 99 : BindingExpression (hash=9343812): Replace item at level 0 with {NullDataItem}
System.Windows.Data Warning: 74 : BindingExpression (hash=9343812): Activate with root item BackupViewModel (hash=58266349)
System.Windows.Data Warning: 104 : BindingExpression (hash=9343812):   At level 0 - for BackupViewModel.IsViewVisible found accessor RuntimePropertyInfo(IsViewVisible)
System.Windows.Data Warning: 100 : BindingExpression (hash=9343812): Replace item at level 0 with BackupViewModel (hash=58266349), using accessor RuntimePropertyInfo(IsViewVisible)
System.Windows.Data Warning: 97 : BindingExpression (hash=9343812): GetValue at level 0 from BackupViewModel (hash=58266349) using RuntimePropertyInfo(IsViewVisible): 'True'
System.Windows.Data Warning: 76 : BindingExpression (hash=9343812): TransferValue - got raw value 'True'
System.Windows.Data Warning: 85 : BindingExpression (hash=9343812): TransferValue - using final value 'True'
System.Windows.Data Warning: 75 : BindingExpression (hash=9343812): Deactivate
System.Windows.Data Warning: 99 : BindingExpression (hash=9343812): Replace item at level 0 with {NullDataItem}
System.Windows.Data Warning: 59 : BindingExpression (hash=9343812): Detach

Answer 1

你确定它真的没有“束缚”吗？我已经把它发生在我身上，看起来像你的遗失...你没有任何迹象表明

NotifyOnSourceUpdated =真

在你的{binding Mode ....}内容

中

Answer 2

它似乎是一种语法的东西......它似乎根本没有绑定到你的ViewModel。试试这个：

<RadioButton Grid.Row="0" x:Name="BackupButton" Style="{StaticResource {x:Type ToggleButton}}" IsChecked="{Binding IsViewVisible, Mode=TwoWay}">
    Backup
    <RadioButton.DataContext>
        <local:BackupVM />
    </RadioButton.DataContext>
</RadioButton>

您将local namespace定义为：

xmlns:local="clr-namespace:WpfApplication1"

注意：将WpfApplication1替换为命名空间的名称。

为什么我的双向WPF绑定变得分离？

2 个答案: