WPF之自定义用户控件

C#代码：

     public partial class WPFUserControl : UserControl
    {
        public WPFUserControl()
        {
            InitializeComponent();
        }

        //定义依赖项属性
        public static DependencyProperty ColorProperty;
        public static DependencyProperty RedProperty;
        public static DependencyProperty GreenProperty;
        public static DependencyProperty BlueProperty;
        static WPFUserControl()
        {
            //注册依赖项属性
            ColorProperty = DependencyProperty.Register("Color", typeof(Color), typeof(WPFUserControl), new PropertyMetadata(Colors.Black, new PropertyChangedCallback(OnColorChanged)));
            //DependencyProperty.Register(属性名称，属性类型，所属控件类型，注册依赖属性)
            //PropertyMetadata(默认值, PropertyChangedCallback更改时的回调函数)

            RedProperty = DependencyProperty.Register("Red", typeof(byte), typeof(WPFUserControl), new PropertyMetadata( new PropertyChangedCallback(OnColorRGBChanged)));
            BlueProperty = DependencyProperty.Register("Blue", typeof(byte), typeof(WPFUserControl), new PropertyMetadata( new PropertyChangedCallback(OnColorRGBChanged)));
            GreenProperty = DependencyProperty.Register("Green", typeof(byte), typeof(WPFUserControl), new PropertyMetadata( new PropertyChangedCallback(OnColorRGBChanged)));
        }
        //声明属性
        public Color Color
        {
            get { return (Color)GetValue(ColorProperty); }
            set { SetValue(ColorProperty, value); }
        }
        public byte Red
        {
            get { return (byte)GetValue(RedProperty); }
            set { SetValue(RedProperty, value); }
        }
        public byte Blue
        {
            get { return (byte)GetValue(BlueProperty); }
            set { SetValue(BlueProperty, value); }
        }
        public byte Green
        {
            get { return (byte)GetValue(GreenProperty); }
            set { SetValue(GreenProperty, value); }
        }
        //声明回调函数方法
        private static void OnColorRGBChanged(DependencyObject sender, DependencyPropertyChangedEventArgs e)
        {
            WPFUserControl colorPicker = (WPFUserControl)sender;
            Color color = colorPicker.Color;
            if (e.Property == RedProperty)
            {
                color.R = (byte)e.NewValue;
            }
            else if (e.Property == GreenProperty)
            {
                color.G = (byte)e.NewValue;
            }
            else if (e.Property == BlueProperty)
            {
                color.B = (byte)e.NewValue;
            }
            colorPicker.Color = color;
        }
        //声明回调函数方法
        private static void OnColorChanged(DependencyObject sender, DependencyPropertyChangedEventArgs e)
        {
            WPFUserControl colorPicker = (WPFUserControl)sender;
            Color color = colorPicker.Color;
            Color oldColor = (Color)e.OldValue;
            Color newColor = (Color)e.NewValue;
            colorPicker.Red = newColor.R;
            colorPicker.Green = newColor.G;
            colorPicker.Blue = newColor.B;
            colorPicker.OnColorChanged(oldColor,newColor);
        }
        //注册路由事件
        private static readonly RoutedEvent ColorChangedEvent = EventManager.RegisterRoutedEvent("ColorChanged", RoutingStrategy.Bubble, typeof(RoutedPropertyChangedEventHandler), typeof(WPFUserControl));

        //RoutedEvent:表示和标识路由事件，并声明其特征。
        //EventManager类：提供事件相关的实用工具方法，这些方法可为类所有者注册路由事件，并添加类处理程序。
        //EventManager.RegisterRoutedEvent方法：向 Windows Presentation Foundation (WPF) 事件系统注册新的路由事件
        //EventManager.RegisterRoutedEvent(路由事件的名称,RoutingStrategy路由策略,事件处理程序的类型，路由事件的所有者类类型)
        //RoutedPropertyChangedEventHandler：表示将处理跟踪属性值更改的各个路由事件的方法。

        //声明事件
        public event RoutedPropertyChangedEventHandler ColorChanged
        {
            add { AddHandler(ColorChangedEvent, value); }  
            //为指定的路由事件添加路由事件处理程序，并将该处理程序添加到当前元素的处理程序集合中。
            remove { RemoveHandler(ColorChangedEvent, value); } 
            //从此元素中删除指定的路由事件处理程序。
        }

        //事件引发
        private void OnColorChanged(Color oldValue, Color newValue)
        {
            RoutedPropertyChangedEventArgs args = new RoutedPropertyChangedEventArgs(oldValue,newValue);
            args.RoutedEvent = WPFUserControl.ColorChangedEvent;
            UIElement.RaiseEvent(args);//继承引发事件
            //RoutedPropertyChangedEventArgs 类:提供有关依赖属性值更改的数据（由特定的路由事件报告），其中包含发生更改的属性的旧值和新值。
            //RaiseEvent:获取或设置与此 RoutedEventArgs 实例关联的 RoutedEvent。
            //RoutedEventArgs 类:包含与路由事件相关联的状态信息和事件数据。
            //RaiseEvent：引发特定路由事件。 在提供的 RoutedEventArgs 实例内标识将引发的 RoutedEvent（作为该事件数据的 RoutedEvent 属性）。
        }
    }

Xaml代码

"wpf.WPFUserControl"
             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:wpf"
             Name="colorPicker">
    <Grid>
        <Grid.RowDefinitions>
            "auto"/>
            "auto"/>
            "auto"/>
        Grid.RowDefinitions>
        <Grid.ColumnDefinitions>
            
            "auto"/>
        Grid.ColumnDefinitions>
        <Slider Name="SliderRed" Minimum="0" Maximum="255" Margin="{Binding ElementName=colorPicker,Path=Padding}" Value="{Binding ElementName=colorPicker,Path=Red}">Slider>
        <Slider Name="SliderGreen"  Grid.Row="1" Minimum="0" Maximum="255" Margin="{Binding ElementName=colorPicker,Path=Padding}" Value="{Binding ElementName=colorPicker,Path=Green}">Slider>
        <Slider Name="SliderBlue"  Grid.Row="2" Minimum="0" Maximum="255" Margin="{Binding ElementName=colorPicker,Path=Padding}" Value="{Binding ElementName=colorPicker,Path=Blue}">Slider>
        <Rectangle Grid.Column="1" Grid.RowSpan="3" Margin="{Binding ElementName=colorPicker,Path=Padding}" Width="50" Stroke="Black" StrokeThickness="1">
            <Rectangle.Fill>
                "{Binding ElementName=colorPicker,Path=Color}"/>
            Rectangle.Fill>

        Rectangle> 
    Grid>