Question

我在Silverlight中有一个数据导航用户控件，它打开一个子窗口，用户可以在其中输入搜索条件，当他们按下“应用”时，它会更新ViewModel中的绑定属性（MVVM模式。）

链接是：SearchDialog＆lt; - ＆gt; DataNavigator＆lt; - ＆gt; MyView＆lt; - ＆gt; MyViewModel

SearchDialog中的依赖项属性似乎有效，当我设置其值时，它会显示在DataNavigator中;但是当依赖属性更改时，似乎没有通知从DataNavigator发送到MyView / MyViewModel。

SearchDialog派生自ChildWindow：

public string Search
{
 get { return (string)GetValue(SearchProperty); }
 set { SetValue(SearchProperty, value); }
}

public static readonly DependencyProperty SearchProperty =
 DependencyProperty.Register("Search", typeof(string), typeof(SearchDialog),
 new PropertyMetadata(null));

DataNavigator派生自UserControl：

public Binding Search { get; set; }

private void DataNavigator_Loaded(object sender, Windows.RoutedEventArgs e)
{
 if (Search != null)
  this._searchDialog.SetBinding(SearchDialog.SearchProperty, Search);
}

MyView派生自SilverlightFX.UserInterface.Navigation.Page：

<DataNavigator MovePreviousAction="$model.MovePrevious()"
               CurrentIndex="{Binding CurrentIndex, Mode=TwoWay}"
               MoveNextAction="$model.MoveNext()"
               SaveAction="$model.SaveChanges()"
               IsLoading="{Binding IsLoading, Converter={StaticResource VisibilityConverter}}"
               Search="{Binding SearchString, Mode=TwoWay}"/>

MyViewModel派生自ViewModel：

public string SearchString
    {
     get { return this._search; }

  set
  {
   if(value != this._search)
   {
    this._search = value;
    this.RaisePropertyChanged("SearchString");
   }
  }
 }

我一直在努力寻找问题，但没有取得任何成功;谁有人看到这个问题？提前谢谢，

Answer 1

由于您尝试将其绑定到string类型的属性，因此不确定中间的Binding属性是否有效。

由于你已经使用了一些Nikhil的东西，你可能想看看how he uses Tasks to handle dialogs/child windows，同时仍然保持MVVM范例。

Answer 2

Bryant's solution看起来是正确的方法，但我仍然遇到了一些问题。我最终使用以下方法让它工作：

我向SearchDialog添加了一个事件，只要搜索模式DP发生变化就会触发该事件：

public string Search
{
    get { return (string)GetValue(SearchProperty); }
    set { SetValue(SearchProperty, value); }
}

public static readonly DependencyProperty SearchProperty =
    DependencyProperty.Register("Search", typeof(string), typeof(SearchDialog),
    new PropertyMetadata(null, new PropertyChangedCallback(OnSearchChanged)));

private static void OnSearchChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
    // call to instance method
    ((SearchDialog)d).OnSearchChanged(e);
}

protected virtual void OnSearchChanged(DependencyPropertyChangedEventArgs e)
{
    if (SearchChanged != null)
        this.SearchChanged(this, e);
}

public event DependencyPropertyChangedEventHandler SearchChanged;

之后我在DataNavigator中添加了另一个DP：

public string Search
{
    get { return (string)GetValue(SearchProperty); }
    set { SetValue(SearchProperty, value); }
}

public static readonly Windows.DependencyProperty SearchProperty =
Windows.DependencyProperty.Register("Search", typeof(string), typeof(DataNavigator),
new Windows.PropertyMetadata(null));

然后将导航器的DP连接到SearchDialog的DP，以便对搜索属性的更改将传播到DataNavigator，然后绑定到V＆amp; VM。

// Inside the Loaded Event:
this._searchDialog.SearchChanged +=
    new System.Windows.DependencyPropertyChangedEventHandler(Search_Changed);

// Handler:
private void Search_Changed(object sender, System.Windows.DependencyPropertyChangedEventArgs e)
{
    string search = this._searchDialog.GetValue(SearchDialog.SearchProperty) as string;
    this.Search = search != null ? search.ToString() : null;
}

剩下的事情和上面的情况一样，我正在寻找我正在寻找的效果。

将Silverlight Custom Control依赖项属性绑定到Model属性

2 个答案: