未使用DataTemplate DataType绑定属性

本文介绍了未使用DataTemplate DataType绑定属性的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我有一个主要的视图模型，可以创建许多子视图模型

I have a main viewmodel which create many child viewmodel

通过以下方式定义子vm数据模板:

The child vm datatemplate is definied in the following way:

<DataTemplate DataType="{x:Type vm:ChildVM}"> <view:childview /> </DataTemplate>

子视图具有以下代码:

<TextBox> <i:Interaction.Behaviors> <behavior:AppendTextBehavior AppendTextAction="{Binding AppendTextAction, Mode=OneWayToSource}" /> </i:Interaction.Behaviors> </TextBox>

行为类:

public class AppendTextBehavior : Behavior<TextBox> { public Action<string> AppendTextAction { get { return (Action<string>)GetValue(AppendTextActionProperty); } set { SetValue(AppendTextActionProperty, value); } } public static readonly DependencyProperty AppendTextActionProperty = DependencyProperty.Register("AppendTextAction", typeof(Action<string>), typeof(AppendTextBehavior)); protected override void OnAttached() { base.OnAttached(); SetCurrentValue(AppendTextActionProperty, (Action<string>)AssociatedObject.AppendText); AssociatedObject.TextChanged += AssociatedObject_TextChanged; } void AssociatedObject_TextChanged(object sender, EventArgs e) { // does something } }

ChildVM:

ChildVM :

private Action<string> appendTextAction; public Action<string> AppendTextAction { get { return appendTextAction; } set { appendTextAction = value; RaisePropertyChanged(() => AppendTextAction); } }

推荐答案

F加星标，

Hi F Starred,

>>显然，上面的代码是错误的，因为我不需要再次创建子视图模型.我该怎么做才能使AppendTextAction绑定起作用?

根据您的描述，我认为这可能是您的OnAttached()事件中的一些错误.您可以尝试更改代码.

From your description, I think, it is maybe some errors in your OnAttached() event. You can try to change the code.

protected override void OnAttached() { //set AppendTextAction values AppendTextAction = (Action<string>)AssociatedObject.AppendText; AssociatedObject.TextChanged += (sender, a) => { if (!IsFocused) { AssociatedObject.Focus(); AssociatedObject.Select(AssociatedObject.Text.Length, 0); } }; base.OnAttached(); }

以下文章供您参考.希望对您有帮助.

The following article for your reference. I hope it will helpful for you.

WPF中的附加行为: www.mindscapehq/blog/index .php/2009/02/01/attached-behaviours-in-wpf/

Attached behaviours in WPF: www.mindscapehq/blog/index.php/2009/02/01/attached-behaviours-in-wpf/

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最好的问候，

吕汉楠