WPF- 依赖属性、依赖附加属性以及类型转换

  数据绑定

        基本：声明  注册  包装

        //1  声明        public static DependencyProperty valueProperty;       //2   注册         static DependenProperties()        {            valueProperty = DependencyProperty.Register("value", typeof(string), typeof(DependenProperties),new PropertyMetadata(default(string)));        }        //3 包装         public string value        {            get            {                return (string)this.GetValue(valueProperty);            }            set            {               this.SetValue(valueProperty, "小明");            }        }备注：在类中必须继承 DependencyObject

 ValidateValueCallback :属性值验证回调

  //2   注册  static DependenProperties() {    valueProperty = DependencyProperty.Register("value", typeof(string), typeof(DependenProperties),new PropertyMetadata(default(string),new PropertyChangedCallback (OnValueChangedCallback)),new ValidateValueCallback(OnValidateValueCallback)); }//回调方法必须是静态方法//参数一：DependencyObject  ： 属性所在的对象  //参数二：DependencyPropertyChangedEventArgs ： 变化动作所关联的数据public static void  OnValueChangedCallback(DependencyObject  o,DependencyPropertyChangedEventArgs arg){    ...... }//验证回调函数//参数一：Object ：属性将要写入的值【最新值】//返回值：bool 类型：是否允许写入public static bool  OnValidateValueCallback(Object o){    ......    return true;}

 CoerceValueCallback：强制值回调
  代码如下：

  //2   注册  static DependenProperties() {    valueProperty = DependencyProperty.Register("value", typeof(string), typeof(DependenProperties),new PropertyMetadata(default(string),new PropertyChangedCallback (OnValueChangedCallback),new CoerceValueCallback() ),new ValidateValueCallback(OnValidateValueCallback)); }//回调方法必须是静态方法//参数一：DependencyObject  ： 属性所在的对象  //参数二：DependencyPropertyChangedEventArgs ： 变化动作所关联的数据public static void  OnValueChangedCallback(DependencyObject  o,DependencyPropertyChangedEventArgs arg){    ...... }//验证回调函数//参数一：Object ：属性将要写入的值【最新值】//返回值：bool 类型：是否允许写入public static bool  OnValidateValueCallback(Object o){    ......    return true;}//强制回调函数// <param name="d">属性对象</param>/// <param name="baseValue">当前属性的最新值</param>/// <returns>希望属性可以接收的值</returns>public  static void OnCoerceValueCallback(DependencyObject d, object baseValue){     return  null;}

 PropertyChangedCallback：属性变化回调
  代码如下：

  //2   注册  static DependenProperties() {    valueProperty = DependencyProperty.Register("value", typeof(string), typeof(DependenProperties),new PropertyMetadata(default(string),new PropertyChangedCallback (OnValueChangedCallback) )); }//回调方法必须是静态方法//参数一：DependencyObject  ： 属性所在的对象  //参数二：DependencyPropertyChangedEventArgs ： 变化动作所关联的数据public static void  OnValueChangedCallback(DependencyObject  o,DependencyPropertyChangedEventArgs arg){    ...... }

//属性注册 static CallBack()         {            ValueProperty = DependencyProperty.Register(                "Value",                typeof(string),                typeof(CallBack),                new FrameworkPropertyMetadata(default(string),  FrameworkPropertyMetadataOptions.BindsTwoWayByDefault|  FrameworkPropertyMetadataOptions.AffectsMeasure,                new PropertyChangedCallback(OnValueChangesCallBack),new CoerceValueCallback (OnCoerceValueCallback)),                new ValidateValueCallback(ValidateValueCallback)                );        }//FrameworkPropertyMetadata 对象比PropertyMetadata多了几个参数：//其中的 FrameworkPropertyMetadataOptions. |  FrameworkPropertyMetadataOptions. 选项参数，当值发生变化后他会重新渲染页面，重新显示最新值。 //FrameworkPropertyMetadataOptions选项：
//AffectsArrange、AffectsMeasure、AffectsParentArrange、AffectsParentMeasure：属性变化的时候，需要通知容器进行重新测量和排列。Margin值变化的时候，就会把相邻的对象挤开
//AffectsRender：属性值的变化导致元素重新渲染、重新绘制
//BindsTwoWayByDefault：默认情况以双向绑定的方式处理绑定行为
//Inherits：继承。FontSize，父对象进行这个属性设置的时候，会对子对象进行相同的影响
//IsAnimationProhibited：这个属性不能用于动画
//IsNotDataBindable：不能使用表达式，设置依赖属性
//Journal：Page开发，属性的值会被保存到 日志
//SubPropertiesDoNotAffectRender：对象属性子属性变化时，不去重新渲染对象
//DefaultValue：默认值

  public static DependencyProperty PasswordValueProperty;

   public static readonly DependencyProperty MyPropertyProperty =            DependencyProperty.RegisterAttached("PasswordValue", typeof(string), typeof(Controller),                 new PropertyMetadata(default(string),                     new PropertyChangedCallback(OnPropertyChangedCallback) )                                );

      public static string  GetPasswordValue(DependencyObject obj)        {            return (string)obj.GetValue(MyPropertyProperty);        }
        public static void SetPasswordValue(DependencyObject obj, string  value)        {            obj.SetValue(MyPropertyProperty, value);        }

  public static void OnPropertyChangedCallback(DependencyObject d, DependencyPropertyChangedEventArgs e)        {            (d as PasswordBox).Password = (string)e.NewValue;           }

<Window x:Class="WpfApp1.DependenProperties.DependenProperties"        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:WpfApp1.DependenProperties"        xmlns:sys="clr-namespace:System;assembly=System.Runtime"        mc:Ignorable="d"        Title="DependenProperties" Height="450" Width="800">    <Window.Resources>        <sys:String x:Key="pwd">123</sys:String>    </Window.Resources>    <Grid>        <PasswordBox Password="" local:Controller.PasswordValue="{Binding Source={StaticResource pwd}}"></PasswordBox>     </Grid></Window>

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;
namespace WpfApp1.TypeConverterDemo{    [TypeConverter(typeof(TypeConvertDemo))]    public class Control    {        public double Width { get; set; }           public double Height { get; set; }
    }
    public class ControlProperty:ContentControl {         public Control Value        {            get { return (Control)GetValue(ValueProperty); }            set { SetValue(ValueProperty, value); }        }         public static readonly DependencyProperty ValueProperty =            DependencyProperty.Register("Value", typeof(Control), typeof(ControlProperty), new PropertyMetadata(null)); 
    }}

using System;using System.Collections.Generic;using System.ComponentModel;using System.Globalization;using System.Linq;using System.Text;using System.Threading.Tasks;namespace WpfApp1.TypeConverterDemo{    public class TypeConvertDemo : TypeConverter    {        /// <summary>        ///类型转换        /// </summary>        /// <param name="context">上下文</param>        /// <param name="culture">当前本地化信息</param>        /// <param name="value">传递值</param>        /// <returns></returns>        public override object? ConvertFrom(ITypeDescriptorContext? context, CultureInfo? culture, object value)        {            var temp = Convert.ToString(value).Split(',');            var c = new Control()            {                Width = Convert.ToDouble(temp[0]),                Height = Convert.ToDouble(temp[1])            };            return c;        }    }}

<Window x:Class="WpfApp1.TypeConverterDemo.Window1"        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:WpfApp1.TypeConverterDemo"        mc:Ignorable="d"        Title="Window1" Height="450" Width="800">    <Grid>        <local:ControlProperty Value="12,34" x:Name="cc"></local:ControlProperty>        <Button Content="提交" Click="Button_Click"></Button>    </Grid></Window>

using System;using System.Collections.Generic;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.Shapes;
namespace WpfApp1.TypeConverterDemo{    /// <summary>    /// Window1.xaml 的交互逻辑    /// </summary>    public partial class Window1 : Window    {        public Window1()        {            InitializeComponent();        }
        private void Button_Click(object sender, RoutedEventArgs e)        {            _ = this.cc.Value;        }    }}