C# 为什么我的自定义用户控件'；s的依赖项属性不适用于绑定？_C#_Wpf_Data Binding_Xaml_Dependency Properties

C# 为什么我的自定义用户控件'；s的依赖项属性不适用于绑定？

c# wpf data-binding xaml

C# 为什么我的自定义用户控件'；s的依赖项属性不适用于绑定？,c#,wpf,data-binding,xaml,dependency-properties,C#,Wpf,Data Binding,Xaml,Dependency Properties,如果值是调用它的XAML中定义的静态值，则自定义UserControl的dependency属性将正确绑定，如下所示： ItemTypeIdCode="addresses" 但如果该值是动态绑定的，则不会： ItemTypeIdCode="{Binding ItemTypeIdCode}" 我必须对自定义UserControl做什么才能使它的dependency属性对绑定到另一个控件中的值作出反应？这是我的密码： XAML: <Window x:Class="TestDepenPro

如果值是调用它的XAML中定义的静态值，则自定义UserControl的dependency属性将正确绑定，如下所示：

ItemTypeIdCode="addresses"

但如果该值是动态绑定的，则不会：

ItemTypeIdCode="{Binding ItemTypeIdCode}"

我必须对自定义UserControl做什么才能使它的dependency属性对绑定到另一个控件中的值作出反应？

这是我的密码：

XAML:

<Window x:Class="TestDepenProp.Window1"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:controls="clr-namespace:TestDepenProp.Controls"
    Title="Window1" Height="300" Width="300">
    <StackPanel 
        HorizontalAlignment="Left"
        Margin="10">
        <controls:DropDown 
            ItemTypeIdCode="{Binding ItemTypeIdCode}"  
            SelectedValue="672"
            Width="150"
            Margin="0 0 0 5"/>
        <TextBlock Text="{Binding ItemTypeIdCode}"/>
    </StackPanel>
</Window>

using System.Windows;
using System.ComponentModel;

namespace TestDepenProp
{
    public partial class Window1 : Window, INotifyPropertyChanged
    {
        #region ViewModelProperty: ItemTypeIdCode
        private string _itemTypeIdCode;
        public string ItemTypeIdCode
        {
            get
            {
                return _itemTypeIdCode;
            }

            set
            {
                _itemTypeIdCode = value;
                OnPropertyChanged("ItemTypeIdCode");
            }
        }
        #endregion

        public Window1()
        {
            InitializeComponent();
            DataContext = this;

            ItemTypeIdCode = "addresses";
        }
        #region INotifiedProperty Block
        public event PropertyChangedEventHandler PropertyChanged;

        protected void OnPropertyChanged(string propertyName)
        {
            PropertyChangedEventHandler handler = PropertyChanged;

            if (handler != null)
            {
                handler(this, new PropertyChangedEventArgs(propertyName));
            }
        }
        #endregion
    }
}

<UserControl x:Class="TestDepenProp.Controls.DropDown"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
    <StackPanel>
        <ComboBox SelectedValuePath="Key"
                  DisplayMemberPath="Value"
                  SelectedValue="{Binding SelectedValue}"
                  Margin="0 0 0 10"
                  ItemsSource="{Binding DropDownValues}" />
    </StackPanel>
</UserControl>

using System.Windows;
using System.Windows.Controls;
using System.ComponentModel;
using System.Collections.ObjectModel;
using System.Collections.Generic;

namespace TestDepenProp.Controls
{
    public partial class DropDown : UserControl, INotifyPropertyChanged
    {

        public static readonly DependencyProperty ItemTypeIdCodeProperty = DependencyProperty.Register("ItemTypeIdCode", typeof(string), typeof(DropDown));

        public string ItemTypeIdCode
        {
            get { return (string)GetValue(ItemTypeIdCodeProperty); }
            set { SetValue(ItemTypeIdCodeProperty, value); }
        }

        #region ViewModelProperty: DropDownValues
        private ObservableCollection<KeyValuePair<string, string>> _dropDownValues = new ObservableCollection<KeyValuePair<string, string>>();
        public ObservableCollection<KeyValuePair<string, string>> DropDownValues
        {
            get
            {
                return _dropDownValues;
            }

            set
            {
                _dropDownValues = value;
                OnPropertyChanged("DropDownValues");
            }
        }
        #endregion

        #region ViewModelProperty: SelectedValue
        private string _selectedValue;
        public string SelectedValue
        {
            get
            {
                return _selectedValue;
            }

            set
            {
                _selectedValue = value;
                OnPropertyChanged("SelectedValue");
            }
        }
        #endregion

        public DropDown()
        {
            InitializeComponent();
            DataContext = this;

            Loaded += new RoutedEventHandler(DropDown_Loaded);
        }

        void DropDown_Loaded(object sender, RoutedEventArgs e)
        {
            GetDropDownValues();
        }

        void GetDropDownValues()
        {
            switch (ItemTypeIdCode)
            {
                case "addresses":
                    DropDownValues.Add(new KeyValuePair<string, string>("111", "762 Main St."));
                    DropDownValues.Add(new KeyValuePair<string, string>("222", "7384 First Ave."));
                    DropDownValues.Add(new KeyValuePair<string, string>("333", "8728 Second St."));
                    break;
                case "customers":
                    DropDownValues.Add(new KeyValuePair<string, string>("672", "Jim Smith"));
                    DropDownValues.Add(new KeyValuePair<string, string>("281", "James Anders"));
                    DropDownValues.Add(new KeyValuePair<string, string>("321", "Angie Wonderson"));
                    DropDownValues.Add(new KeyValuePair<string, string>("221", "Hal Cloud"));
                    DropDownValues.Add(new KeyValuePair<string, string>("123", "Hugh Brandley"));
                    break;
                default:
                    break;
            }
        }


        #region INotifiedProperty Block
        public event PropertyChangedEventHandler PropertyChanged;

        protected void OnPropertyChanged(string propertyName)
        {
            PropertyChangedEventHandler handler = PropertyChanged;

            if (handler != null)
            {
                handler(this, new PropertyChangedEventArgs(propertyName));
            }
        }
        #endregion


    }
}

下拉列表。xaml:

<Window x:Class="TestDepenProp.Window1"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:controls="clr-namespace:TestDepenProp.Controls"
    Title="Window1" Height="300" Width="300">
    <StackPanel 
        HorizontalAlignment="Left"
        Margin="10">
        <controls:DropDown 
            ItemTypeIdCode="{Binding ItemTypeIdCode}"  
            SelectedValue="672"
            Width="150"
            Margin="0 0 0 5"/>
        <TextBlock Text="{Binding ItemTypeIdCode}"/>
    </StackPanel>
</Window>

using System.Windows;
using System.ComponentModel;

namespace TestDepenProp
{
    public partial class Window1 : Window, INotifyPropertyChanged
    {
        #region ViewModelProperty: ItemTypeIdCode
        private string _itemTypeIdCode;
        public string ItemTypeIdCode
        {
            get
            {
                return _itemTypeIdCode;
            }

            set
            {
                _itemTypeIdCode = value;
                OnPropertyChanged("ItemTypeIdCode");
            }
        }
        #endregion

        public Window1()
        {
            InitializeComponent();
            DataContext = this;

            ItemTypeIdCode = "addresses";
        }
        #region INotifiedProperty Block
        public event PropertyChangedEventHandler PropertyChanged;

        protected void OnPropertyChanged(string propertyName)
        {
            PropertyChangedEventHandler handler = PropertyChanged;

            if (handler != null)
            {
                handler(this, new PropertyChangedEventArgs(propertyName));
            }
        }
        #endregion
    }
}

<UserControl x:Class="TestDepenProp.Controls.DropDown"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
    <StackPanel>
        <ComboBox SelectedValuePath="Key"
                  DisplayMemberPath="Value"
                  SelectedValue="{Binding SelectedValue}"
                  Margin="0 0 0 10"
                  ItemsSource="{Binding DropDownValues}" />
    </StackPanel>
</UserControl>

using System.Windows;
using System.Windows.Controls;
using System.ComponentModel;
using System.Collections.ObjectModel;
using System.Collections.Generic;

namespace TestDepenProp.Controls
{
    public partial class DropDown : UserControl, INotifyPropertyChanged
    {

        public static readonly DependencyProperty ItemTypeIdCodeProperty = DependencyProperty.Register("ItemTypeIdCode", typeof(string), typeof(DropDown));

        public string ItemTypeIdCode
        {
            get { return (string)GetValue(ItemTypeIdCodeProperty); }
            set { SetValue(ItemTypeIdCodeProperty, value); }
        }

        #region ViewModelProperty: DropDownValues
        private ObservableCollection<KeyValuePair<string, string>> _dropDownValues = new ObservableCollection<KeyValuePair<string, string>>();
        public ObservableCollection<KeyValuePair<string, string>> DropDownValues
        {
            get
            {
                return _dropDownValues;
            }

            set
            {
                _dropDownValues = value;
                OnPropertyChanged("DropDownValues");
            }
        }
        #endregion

        #region ViewModelProperty: SelectedValue
        private string _selectedValue;
        public string SelectedValue
        {
            get
            {
                return _selectedValue;
            }

            set
            {
                _selectedValue = value;
                OnPropertyChanged("SelectedValue");
            }
        }
        #endregion

        public DropDown()
        {
            InitializeComponent();
            DataContext = this;

            Loaded += new RoutedEventHandler(DropDown_Loaded);
        }

        void DropDown_Loaded(object sender, RoutedEventArgs e)
        {
            GetDropDownValues();
        }

        void GetDropDownValues()
        {
            switch (ItemTypeIdCode)
            {
                case "addresses":
                    DropDownValues.Add(new KeyValuePair<string, string>("111", "762 Main St."));
                    DropDownValues.Add(new KeyValuePair<string, string>("222", "7384 First Ave."));
                    DropDownValues.Add(new KeyValuePair<string, string>("333", "8728 Second St."));
                    break;
                case "customers":
                    DropDownValues.Add(new KeyValuePair<string, string>("672", "Jim Smith"));
                    DropDownValues.Add(new KeyValuePair<string, string>("281", "James Anders"));
                    DropDownValues.Add(new KeyValuePair<string, string>("321", "Angie Wonderson"));
                    DropDownValues.Add(new KeyValuePair<string, string>("221", "Hal Cloud"));
                    DropDownValues.Add(new KeyValuePair<string, string>("123", "Hugh Brandley"));
                    break;
                default:
                    break;
            }
        }


        #region INotifiedProperty Block
        public event PropertyChangedEventHandler PropertyChanged;

        protected void OnPropertyChanged(string propertyName)
        {
            PropertyChangedEventHandler handler = PropertyChanged;

            if (handler != null)
            {
                handler(this, new PropertyChangedEventArgs(propertyName));
            }
        }
        #endregion


    }
}

下拉列表.xaml.cs:

<Window x:Class="TestDepenProp.Window1"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:controls="clr-namespace:TestDepenProp.Controls"
    Title="Window1" Height="300" Width="300">
    <StackPanel 
        HorizontalAlignment="Left"
        Margin="10">
        <controls:DropDown 
            ItemTypeIdCode="{Binding ItemTypeIdCode}"  
            SelectedValue="672"
            Width="150"
            Margin="0 0 0 5"/>
        <TextBlock Text="{Binding ItemTypeIdCode}"/>
    </StackPanel>
</Window>

using System.Windows;
using System.ComponentModel;

namespace TestDepenProp
{
    public partial class Window1 : Window, INotifyPropertyChanged
    {
        #region ViewModelProperty: ItemTypeIdCode
        private string _itemTypeIdCode;
        public string ItemTypeIdCode
        {
            get
            {
                return _itemTypeIdCode;
            }

            set
            {
                _itemTypeIdCode = value;
                OnPropertyChanged("ItemTypeIdCode");
            }
        }
        #endregion

        public Window1()
        {
            InitializeComponent();
            DataContext = this;

            ItemTypeIdCode = "addresses";
        }
        #region INotifiedProperty Block
        public event PropertyChangedEventHandler PropertyChanged;

        protected void OnPropertyChanged(string propertyName)
        {
            PropertyChangedEventHandler handler = PropertyChanged;

            if (handler != null)
            {
                handler(this, new PropertyChangedEventArgs(propertyName));
            }
        }
        #endregion
    }
}

<UserControl x:Class="TestDepenProp.Controls.DropDown"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
    <StackPanel>
        <ComboBox SelectedValuePath="Key"
                  DisplayMemberPath="Value"
                  SelectedValue="{Binding SelectedValue}"
                  Margin="0 0 0 10"
                  ItemsSource="{Binding DropDownValues}" />
    </StackPanel>
</UserControl>

using System.Windows;
using System.Windows.Controls;
using System.ComponentModel;
using System.Collections.ObjectModel;
using System.Collections.Generic;

namespace TestDepenProp.Controls
{
    public partial class DropDown : UserControl, INotifyPropertyChanged
    {

        public static readonly DependencyProperty ItemTypeIdCodeProperty = DependencyProperty.Register("ItemTypeIdCode", typeof(string), typeof(DropDown));

        public string ItemTypeIdCode
        {
            get { return (string)GetValue(ItemTypeIdCodeProperty); }
            set { SetValue(ItemTypeIdCodeProperty, value); }
        }

        #region ViewModelProperty: DropDownValues
        private ObservableCollection<KeyValuePair<string, string>> _dropDownValues = new ObservableCollection<KeyValuePair<string, string>>();
        public ObservableCollection<KeyValuePair<string, string>> DropDownValues
        {
            get
            {
                return _dropDownValues;
            }

            set
            {
                _dropDownValues = value;
                OnPropertyChanged("DropDownValues");
            }
        }
        #endregion

        #region ViewModelProperty: SelectedValue
        private string _selectedValue;
        public string SelectedValue
        {
            get
            {
                return _selectedValue;
            }

            set
            {
                _selectedValue = value;
                OnPropertyChanged("SelectedValue");
            }
        }
        #endregion

        public DropDown()
        {
            InitializeComponent();
            DataContext = this;

            Loaded += new RoutedEventHandler(DropDown_Loaded);
        }

        void DropDown_Loaded(object sender, RoutedEventArgs e)
        {
            GetDropDownValues();
        }

        void GetDropDownValues()
        {
            switch (ItemTypeIdCode)
            {
                case "addresses":
                    DropDownValues.Add(new KeyValuePair<string, string>("111", "762 Main St."));
                    DropDownValues.Add(new KeyValuePair<string, string>("222", "7384 First Ave."));
                    DropDownValues.Add(new KeyValuePair<string, string>("333", "8728 Second St."));
                    break;
                case "customers":
                    DropDownValues.Add(new KeyValuePair<string, string>("672", "Jim Smith"));
                    DropDownValues.Add(new KeyValuePair<string, string>("281", "James Anders"));
                    DropDownValues.Add(new KeyValuePair<string, string>("321", "Angie Wonderson"));
                    DropDownValues.Add(new KeyValuePair<string, string>("221", "Hal Cloud"));
                    DropDownValues.Add(new KeyValuePair<string, string>("123", "Hugh Brandley"));
                    break;
                default:
                    break;
            }
        }


        #region INotifiedProperty Block
        public event PropertyChangedEventHandler PropertyChanged;

        protected void OnPropertyChanged(string propertyName)
        {
            PropertyChangedEventHandler handler = PropertyChanged;

            if (handler != null)
            {
                handler(this, new PropertyChangedEventArgs(propertyName));
            }
        }
        #endregion


    }
}

使用System.Windows；
使用System.Windows.Controls；
使用系统组件模型；
使用System.Collections.ObjectModel；
使用System.Collections.Generic；
命名空间TestDepenProp.Controls
{
公共部分类下拉列表：UserControl，INotifyPropertyChanged
{
公共静态只读DependencyProperty ItemTypeIdCodeProperty=DependencyProperty.Register（“ItemTypeIdCode”、typeof（字符串）、typeof（下拉菜单））；
公共字符串ItemTypeIdCode
{
获取{return（string）GetValue（ItemTypeIdCodeProperty）；}
set{SetValue（ItemTypeIdCodeProperty，value）；}
}
#区域ViewModelProperty:DropDownValues
私有ObservableCollection_dropDownValues=新ObservableCollection（）；
公共可观察收集下拉列表值
{
得到
{
返回_dropdown值；
}
设置
{
_下拉值=值；
OnPropertyChanged（“DropDownValues”）；
}
}
#端区
#区域视图模型属性：SelectedValue
私有字符串\u selectedValue；
公共字符串SelectedValue
{
得到
{
返回_selectedValue；
}
设置
{
_selectedValue=值；
OnPropertyChanged（“SelectedValue”）；
}
}
#端区
公共下拉列表（）
{
初始化组件（）；
DataContext=this；
已加载+=新路由EventHandler（下拉菜单\u已加载）；
}
已加载无效下拉列表（对象发送器、路由目标）
{
GetDropDownValues（）；
}
void GetDropDownValues（）
{
开关（ItemTypeIdCode）
{
案例“地址”：
添加（新的键值对（“111”，“762大街”）；
添加（新的KeyValuePair（“222”、“7384第一大道”）；
添加（新的键值对（“333”，“8728秒圣”）；
打破
案例“客户”：
添加（新的键值对（“672”，“Jim Smith”）；
添加（新的KeyValuePair（“281”，“James Anders”）；
添加（新的KeyValuePair（“321”，“Angie Wonderson”）；
添加（新的KeyValuePair（“221”，“Hal云”）；
添加（新的KeyValuePair（“123”，“Hugh Brandley”）；
打破
违约：
打破
}
}
#区域INotifiedProperty块
公共事件属性更改事件处理程序属性更改；
受保护的无效OnPropertyChanged（字符串propertyName）
{
PropertyChangedEventHandler处理程序=PropertyChanged；
if（处理程序！=null）
{
处理程序（这是新的PropertyChangedEventArgs（propertyName））；
}
}
#端区
}
}

我认为您需要将PropertyChangedCallback添加到ItemTypeIdCodeProperty依赖属性中。在此回调中，您将调用GetDropDownValues（）。

我猜组合框不会显示任何条目。这确实有点棘手。控件在两个完全独立的“地址空间”中工作。第一个是它自己的数据，就像所有依赖属性一样。第二个“ADRESE空间”是它从其父级继承的数据上下文。如果没有执行任何特殊操作，则所有绑定都会在数据上下文上工作。如果要引用控件的数据，则需要为自己添加一个明确的“引用”：

<UserControl x:Class="TestDepenProp.Controls.DropDown"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Name="self">
<StackPanel>
    <ComboBox SelectedValuePath="Key"
              DisplayMemberPath="Value"
              SelectedValue="{Binding SelectedValue, ElementName=self}"
              Margin="0 0 0 10"
              ItemsSource="{Binding DropDownValues, ElementName=self}" />
</StackPanel>

不需要OnPropertyChanged，这已经由依赖属性逻辑处理。

我猜组合框不显示任何条目。这确实有点棘手。控件在两个完全独立的“地址空间”中工作。第一个是它自己的数据，就像所有依赖属性一样。第二个“ADRESE空间”是它从其父级继承的数据上下文。如果没有执行任何特殊操作，则所有绑定都会在数据上下文上工作。如果要引用控件的数据，则需要为自己添加一个明确的“引用”：

<UserControl x:Class="TestDepenProp.Controls.DropDown"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Name="self">
<StackPanel>
    <ComboBox SelectedValuePath="Key"
              DisplayMemberPath="Value"
              SelectedValue="{Binding SelectedValue, ElementName=self}"
              Margin="0 0 0 10"
              ItemsSource="{Binding DropDownValues, ElementName=self}" />
</StackPanel>

不需要OnPropertyChanged，这已经由依赖属性逻辑处理