Silverlight Datagrid上UpdateSourceTrigger LostFocus的解决方法？ [英] Workaround for UpdateSourceTrigger LostFocus on Silverlight Datagrid?

问题描述

我有一个Silverlight 2应用程序验证数据OnTabSelectionChanged。立即我开始希望UpdateSourceTrigger允许的不仅仅是LostFocus，因为如果您在不勾选控件的情况下单击该选项卡，则在验证之前不更新LINQ对象。

我通过将焦点设置为另一个控件，然后重新启动OnTextChanged：

  Private Sub OnTextChanged（ByVal sender As Object，ByVal e As TextChangedEventArgs）
 txtSetFocus.Focus（）
 sender.Focus（）
 End Sub 
  

现在我试图在DataGrid中完成同样的攻击。我的DataGrid使用在运行时生成的CellTemplate和CellEditingTemplate的DataTemplates。我尝试将TextChanged =OnTextChanged写入DataTemplate中的TextBox，但不会触发。

任何人都有任何想法？

解决方案

你可以通过应用于文本框的行为来做到这一点

  // xmlns：int是System.Windows.Interactivity.DLL中的System.Windows.Interactivity 
 // xmlns：behavior是您下面的类的命名空间
< TextBox Text = {Binding Description，Mode = TwoWay，UpdateSourceTrigger = Explicit}> 
< int：Interaction.Behaviors> 
< behavior：TextBoxUpdatesTextBindingOnPropertyChanged /> 
< / int：Interaction.Behaviors> 
< / TextBox> 
 
 
 public class TextBoxUpdatesTextBindingOnPropertyChanged：Behavior< TextBox> 
 {
 protected override void OnAttached（）
 {
 base.OnAttached（）; 
 
 AssociatedObject.TextChanged + = new TextChangedEventHandler（TextBox_TextChanged）; 
} 
 
 protected override void OnDetaching（）
 {
 base.OnDetaching（）; 
 
 AssociatedObject.TextChanged  -  = TextBox_TextChanged; 
} 
 
 void TextBox_TextChanged（object sender，TextChangedEventArgs e）
 {
 var bindingExpression = AssociatedObject.GetBindingExpression（TextBox.TextProperty）; 
 bindingExpression.UpdateSource（）; 
} 
} 
  

I have a Silverlight 2 application that validates data OnTabSelectionChanged. Immediately I began wishing that UpdateSourceTrigger allowed more than just LostFocus because if you click the tab without tabbing off of a control the LINQ object is not updated before validation.

I worked around the issue for TextBoxes by setting focus to another control and then back OnTextChanged:

Private Sub OnTextChanged(ByVal sender As Object, ByVal e As TextChangedEventArgs)
    txtSetFocus.Focus()
    sender.Focus()
End Sub

Now I am trying to accomplish the same sort of hack within a DataGrid. My DataGrid uses DataTemplates generated at runtime for the CellTemplate and CellEditingTemplate. I tried writing the TextChanged="OnTextChanged" into the TextBox in the DataTemplate, but it is not triggered.

Anyone have any ideas?

解决方案

You can do it with a behavior applied to the textbox too

// xmlns:int is System.Windows.Interactivity from System.Windows.Interactivity.DLL)
// xmlns:behavior is your namespace for the class below
<TextBox Text="{Binding Description,Mode=TwoWay,UpdateSourceTrigger=Explicit}">
    <int:Interaction.Behaviors>
       <behavior:TextBoxUpdatesTextBindingOnPropertyChanged />
    </int:Interaction.Behaviors>
</TextBox>


public class TextBoxUpdatesTextBindingOnPropertyChanged : Behavior<TextBox>
{
    protected override void OnAttached()
    {
        base.OnAttached();

        AssociatedObject.TextChanged += new TextChangedEventHandler(TextBox_TextChanged);
    }

    protected override void OnDetaching()
    {
        base.OnDetaching();

        AssociatedObject.TextChanged -= TextBox_TextChanged;
    }

    void TextBox_TextChanged(object sender, TextChangedEventArgs e)
    {
        var bindingExpression = AssociatedObject.GetBindingExpression(TextBox.TextProperty);
        bindingExpression.UpdateSource();
    }
}

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