WPF，绑定UserControl不起作用

本文介绍了WPF，绑定UserControl不起作用的处理方法，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 嗨 我在wpf中创建了一个用户控件，并设置了DependencyProperty

公共 部分 class MyUserControl:UserControl { 公共 静态 只读 DependencyProperty DP = DependencyProperty.注册(" 文本" ， typeof ( 字符串)， typeof (MyUserControl))； 公共 字符串文本 { 获取 { 返回 此 .MyTextBox.Text; } 设置 { MyTextBox.Text = 值; } } 公共 MyUserControl() { InitializeComponent(); } }

问题是我无法在应用程序中绑定Text:

< my:MyUserControl 水平对齐 =" 左侧" & gt;

不起作用 但对于其他控件和作品也可以:

< dxe:TextEdit 水平对齐 =" 左侧" pleese帮助我，我在Google上搜索了很多

解决方案

你好 我的解决方案不够标准，但是可以正常工作.我想您也可以找到一种标准方法；) 但是我的解决方案:

公共 部分 class MyUserControl:UserControl { 公共 只读 静态 DependencyProperty TextProperty = DependencyProperty.注册(" 文本" ， typeof ( 字符串)， typeof (MyUserControl)，新 PropertyMetadata(OnTextChanged)); 静态 无效 OnTextChanged(DependencyObject obj， DependencyPropertyChangedEventArgs args) { 如果(TextChanged！= 空) TextChanged(obj); } 公共 委托 void TextChangeHandler(对象发​​送者)； 公共 静态 TextChangeHandler TextChanged; 公共 字符串文本 { 获取 {返回(字符串)此 .GetValue(TextProperty);} 设置 {此 .SetValue(TextProperty，值);} } 公共 MyUserControl()// 构造函数 { InitializeComponent(); TextChanged + = 新 TextChangeHandler((对象发​​送者)= > ; { // 防止强制更改用户控件的其他实例 如果(此 ==(((MyUserControl)sender))) 此 .MyTextBox.Text = 此 .Text; }); 此 .MyTextBox.EditValueChanged + = 新的 EditValueChangedEventHandler((对象发​​送者，EditValueChangedEventArgs e)= > { 此 .Text = MyTextBox.Text; }); } }

并且不要更改其他内容. 希望对您有所帮助！

据我所知，您不应该直接设置/获取值.代替此，您应该像这样使用GetValue/SetValue:

获取 {返回( String ) this .GetValue(DP); } 设置 {此 .SetValue(DP，值); }

不确定要完成的操作.在WPF应用程序中，我总是在类中定义数据，如下所示:

公共 class Mydata:INotifyPropertyChanged { 私有 字符串 userName； 公共 字符串用户名 { 获取 {返回 userName； } 设置 { 如果(userName！= 值) { userName = 值； OnPropertyChanged(()=> this.UserName); } } } 公共 无效 OnPropertyChange(字符串 propertyName) { 如果(PropertyChanged！= 空) PropertyChanged(此，新 PropertyChangedEventArgs(propertyName)); } 公共 无效 OnPropertyChange< t> (表达式< t>> propertyExpression) { OnPropertyChange(propertyExpression.Name); } 公共 事件 PropertyChangedEventHandler PropertyChanged; } </ t > </ func > </ t >

在我的代码中的下一个背后，我有人口代码将该对象公开为公共属性:

.... 公共 Mydata SomeData = 新 SomeData(); 公共 MyUserControl() { 填充(SomeData); } ...

终于在我的绑定中:

< my:myusercontrol horizo​​ntalalignment = " 左" name = " myUserControl" verticalalignment = " 顶部" width = " 74" text = " {绑定路径= SomeData.UserName，Mode = TwoWay}" xmlns:my = " #unknown"/>

在WPF中，所有绑定属性都必须实现INotifyPropertyChanged，并且所有集合都必须封装在ObservableCollection中.

hi I created a user control in wpf and set DependencyProperty

public partial class MyUserControl : UserControl { public static readonly DependencyProperty DP = DependencyProperty.Register ("Text", typeof(string), typeof(MyUserControl)); public string Text { get { return this.MyTextBox.Text; } set { MyTextBox.Text = value; } } public MyUserControl() { InitializeComponent(); } }

the problem is I can not bind Text in my application:

<my:MyUserControl HorizontalAlignment="Left" Name="myUserControl" VerticalAlignment="Top" Width="74" Text="{Binding Path=UserName, Mode=TwoWay}"/>

Doesn''t work but it is ok for other controls and works:

<dxe:TextEdit HorizontalAlignment="Left" Name="textEdit1" VerticalAlignment="Top" Width="73" Text="{Binding Path=UserName, Mode=TwoWay}" />

Pleese help me i googled a lot

解决方案

Hello My solution is not adequately standard but it works. I guess there is also a standard way that you can find ;) But my solution:

public partial class MyUserControl: UserControl { public readonly static DependencyProperty TextProperty = DependencyProperty.Register("Text", typeof(string), typeof(MyUserControl), new PropertyMetadata(OnTextChanged)); static void OnTextChanged(DependencyObject obj, DependencyPropertyChangedEventArgs args) { if (TextChanged != null) TextChanged(obj); } public delegate void TextChangeHandler(object sender); public static TextChangeHandler TextChanged; public string Text { get {return (String)this.GetValue(TextProperty);} set {this.SetValue(TextProperty, value);} } public MyUserControl()//Constructor { InitializeComponent(); TextChanged += new TextChangeHandler((object sender) => { //Prevent forcing changes to other instances of the user control if (this == ((MyUserControl)sender)) this.MyTextBox.Text = this.Text; }); this.MyTextBox.EditValueChanged += new EditValueChangedEventHandler((object sender, EditValueChangedEventArgs e) => { this.Text = MyTextBox.Text; }); } }

And do not change the other things. I hope it''ll help!

As far as I know you shouldn''t set/get value directly. Instead of this you should use GetValue/SetValue like this:

get { return (String)this.GetValue(DP); } set { this.SetValue(DP, value); }

Not sure what exactly you want to accomplish. In my WPF applications I always have my data defined in classes as follows:

public class Mydata:INotifyPropertyChanged { private string userName; public string UserName { get { return userName; } set { if ( userName != value ) { userName = value; OnPropertyChanged(()=>this.UserName); } } } public void OnPropertyChange ( string propertyName ) { if ( PropertyChanged != null ) PropertyChanged( this, new PropertyChangedEventArgs( propertyName ) ); } public void OnPropertyChange<t> ( Expression<func><t>> propertyExpression ) { OnPropertyChange( propertyExpression.Name ); } public event PropertyChangedEventHandler PropertyChanged; } </t></func></t>

Next in my codeBehind I have population code to expose this object as a public property:

.... public Mydata SomeData = new SomeData(); public MyUserControl() { Populate(SomeData); } ...

Finally in my binding :

<my:myusercontrol horizontalalignment="Left" name="myUserControl" verticalalignment="Top" width="74" text="{Binding Path=SomeData.UserName, Mode=TwoWay}" xmlns:my="#unknown" />

In WPF all bound properties MUST implement INotifyPropertyChanged and all collections must be encapsulated in ObservableCollection''s.