WPF usercontrol 自定义依赖属性

1.依赖属性不同意一般属性，一般属性主要定义在对象中，而依赖属性是存在一个特殊的依赖属性表中。
2.当我们触发改变值时，需要通过SetValue这种方式进行触发。

UserControl1.xaml:

<UserControl x:Class="WpfApplication1.UserControl1"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
             xmlns:local="clr-namespace:WpfApplication1"
             mc:Ignorable="d"  Name="myUserControl"
             d:DesignHeight="300" d:DesignWidth="300">
    <Grid>
        <TextBox Name="textBox" TextChanged="textBox_TextChanged"></TextBox>
    </Grid>
</UserControl>

UserControl1.xml.cs:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;

namespace WpfApplication1
{
    /// <summary>
    /// UserControl1.xaml 的交互逻辑
    /// </summary>
    public partial class UserControl1 : UserControl
    {
        public UserControl1()
        {
            InitializeComponent();
        }



        public static readonly DependencyProperty TextContentProperty;

        static UserControl1()
        {
            UserControl1.TextContentProperty =
                                       DependencyProperty.Register("TextContent",
                                       typeof(string), typeof(UserControl1));
        }

        public string TextContent
        {
            get
            {
                return (string)GetValue(UserControl1.TextContentProperty);
            }
            set
            {
                SetValue(UserControl1.TextContentProperty, value);
            }
        }

        private void textBox_TextChanged(object sender, TextChangedEventArgs e)
        {
            TextBox box = (TextBox)sender;
            this.SetValue(TextContentProperty, box.Text);
        }
    }
}

MainWindow.xaml:

<Window x:Class="WpfApplication1.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:WpfApplication1"
        mc:Ignorable="d"
        Name="MainWindowName"
        Title="MainWindow" Height="350" Width="525">
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition></RowDefinition>
            <RowDefinition></RowDefinition>
            <RowDefinition></RowDefinition>
        </Grid.RowDefinitions>
        <TextBlock Name="tc" Grid.Row="0" Width="100" Height="30" Text="{Binding MyValue,ElementName=MainWindowName}"></TextBlock>
        <local:UserControl1 x:Name="uc" Grid.Row="1" Width="50" Height="50" TextContent="{Binding MyValue,Mode=TwoWay,ElementName=MainWindowName}"></local:UserControl1>

    </Grid>
</Window>

MainWindow.xaml.cs:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;

namespace WpfApplication1
{
    /// <summary>
    /// MainWindow.xaml 的交互逻辑
    /// </summary>
    public partial class MainWindow : Window,INotifyPropertyChanged
    {

        public MainWindow()
        {
            InitializeComponent();
            this.DataContext = this;
        }

        private string myVar;

        public event PropertyChangedEventHandler PropertyChanged;
        protected void OnPropertyChanged(string name)
        {
            PropertyChangedEventHandler handler = PropertyChanged;
            if (handler != null)
            {
                handler(this, new PropertyChangedEventArgs(name));
            }
        }
        public string MyValue
        {
            get { return myVar; }
            set { myVar = value;
                OnPropertyChanged("MyValue");
            }
        }
    }
}