原文:
重新想象 Windows 8 Store Apps (16) - 控件基础: 依赖属性, 附加属性, 控件的继承关系, 路由事件和命中测试
重新想象 Windows 8 Store Apps (16) - 控件基础: 依赖属性, 附加属性, 控件的继承关系, 路由事件和命中测试
作者：webabcd
介绍
重新想象 Windows 8 Store Apps 之 控件基础
- DependencyProperty - 依赖属性
- AttachedProperty - 附加属性
- 控件的继承关系
- 路由事件和命中测试
示例
1、开发一个具有 DependencyProperty 和 AttachedProperty 的自定义控件
MyControls/themes/generic.xaml
<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:local="using:MyControls"> <!-- 自定义控件的样式在本文件（themes/generic.xaml）中定义 整合外部 ResourceDictionary --> <ResourceDictionary.MergedDictionaries> <ResourceDictionary Source="ms-appx:///MyControls/themes/MyControl.xaml"/> </ResourceDictionary.MergedDictionaries> </ResourceDictionary>
MyControls/themes/MyControl.xaml
<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:local="using:MyControls"> <Style TargetType="local:MyControl"> <Setter Property="Template"> <Setter.Value> <ControlTemplate TargetType="local:MyControl"> <Border Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}"> <StackPanel> <!--绑定自定义依赖属性--> <TextBlock Text="{TemplateBinding Title}" Foreground="White" FontSize="26.667" /> <!--绑定自定义附加属性--> <TextBlock Text="{TemplateBinding local:MyAttachedProperty.SubTitle}" Foreground="White" FontSize="14.667" /> </StackPanel> </Border> </ControlTemplate> </Setter.Value> </Setter> </Style> </ResourceDictionary>
MyControls/MyControl.cs
/* * 开发一个自定义控件，用于演示依赖属性（Dependency Property）和附加属性（Attached Property） * * 依赖属性：可以用于样式, 模板, 绑定, 动画 * 附加属性：全局可用的依赖属性 */ using Windows.UI.Xaml.Controls; using Windows.UI.Xaml; namespace MyControls { /// <summary> /// 用于依赖属性的演示 /// </summary> public class MyControl : Control { public MyControl() { // 指定默认样式为 typeof(MyControl)，即对应：<Style xmlns:local="using:MyControls" TargetType="local:MyControl" /> this.DefaultStyleKey = typeof(MyControl); } // 通过 DependencyObject.GetValue() 和 DependencyObject.SetValue() 访问依赖属性，这里由 Title 属性封装一下，以方便对依赖属性的访问 public string Title { get { return (string)GetValue(TitleProperty); } set { SetValue(TitleProperty, value); } } // 注册一个依赖属性 public static readonly DependencyProperty TitleProperty = DependencyProperty.Register( "Title", // 依赖属性的名称 typeof(string), // 依赖属性的数据类型 typeof(MyControl), // 依赖属性所属的类 new PropertyMetadata("", PropertyMetadataCallback)); // 指定依赖属性的默认值，以及值发生改变时所调用的方法 private static void PropertyMetadataCallback(DependencyObject sender, DependencyPropertyChangedEventArgs args) { object newValue = args.NewValue; // 发生改变之后的值 object oldValue = args.OldValue; // 发生改变之前的值 } } /// <summary> /// 用于附加属性的演示 /// </summary> public class MyAttachedProperty { // 获取附加属性 public static string GetSubTitle(DependencyObject obj) { return (string)obj.GetValue(SubTitleProperty); } // 设置附加属性 public static void SetSubTitle(DependencyObject obj, string value) { obj.SetValue(SubTitleProperty, value); } // 注册一个附加属性 public static readonly DependencyProperty SubTitleProperty = DependencyProperty.RegisterAttached( "SubTitle", // 附加属性的名称 typeof(string), // 附加属性的数据类型 typeof(MyAttachedProperty), // 附加属性所属的类 new PropertyMetadata("", PropertyMetadataCallback)); // 指定附加属性的默认值，以及值发生改变时所调用的方法 private static void PropertyMetadataCallback(DependencyObject sender, DependencyPropertyChangedEventArgs args) { object newValue = args.NewValue; // 发生改变之后的值 object oldValue = args.OldValue; // 发生改变之前的值 } } }
2、演示依赖属性的使用
Controls/Basic/DependencyPropertyDemo.xaml
<Page x:Class="XamlDemo.Controls.Basic.DependencyPropertyDemo" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:local="using:XamlDemo.Controls.Basic" xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" xmlns:myControls="using:MyControls" mc:Ignorable="d"> <Grid Background="Transparent"> <StackPanel Margin="120 0 0 0"> <!-- 演示如何开发和使用自定义依赖属性（本例所用到的自定义控件请参看：MyControls/MyControl.cs） --> <myControls:MyControl Background="Blue" BorderBrush="Yellow" BorderThickness="1" Width="100" HorizontalAlignment="Left" Title="{Binding Value, ElementName=slider}" /> <Slider Name="slider" Width="100" Minimum="0" Maximum="200" IsThumbToolTipEnabled="False" HorizontalAlignment="Left" /> </StackPanel> </Grid> </Page>
3、演示附加属性的使用
Controls/Basic/AttachedPropertyDemo.xaml
<Page x:Class="XamlDemo.Controls.Basic.AttachedPropertyDemo" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:local="using:XamlDemo.Controls.Basic" xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" xmlns:myControls="using:MyControls" mc:Ignorable="d"> <Grid Background="Transparent"> <StackPanel Margin="120 0 0 0"> <!-- 演示如何开发和使用自定义附加属性（本例所用到的自定义控件请参看：MyControls/MyControl.cs） --> <myControls:MyControl Background="Blue" BorderBrush="Yellow" BorderThickness="1" Width="100" HorizontalAlignment="Left" Title="{Binding Value, ElementName=slider}" myControls:MyAttachedProperty.SubTitle="{Binding Value, ElementName=slider}" /> <Slider Name="slider" Width="100" Minimum="0" Maximum="200" IsThumbToolTipEnabled="False" HorizontalAlignment="Left" /> </StackPanel> </Grid> </Page>
4、控件的继承关系的概述
Controls/Basic/Inherit.xaml
<Page x:Class="XamlDemo.Controls.Basic.Inherit" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:local="using:XamlDemo.Controls.Basic" xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" mc:Ignorable="d"> <Grid Background="Transparent"> <StackPanel Margin="120 0 0 0"> <TextBlock Name="lblMsg" FontSize="14.667" LineHeight="25"> <Run>继承关系: FrameworkElement -> UIElement -> DependencyObject</Run> <LineBreak /> <Run>DependencyObject - 提供对依赖属性的访问，以及获取此对象关联的 CoreDispatcher</Run> <LineBreak /> <Run>UIElement - 可视元素，键盘和鼠标输入等</Run> <LineBreak /> <Run>FrameworkElement - 框架元素，数据绑定，一些公共 API 等。例：Control, TextBlock, WebView 等继承自 FrameworkElement</Run> <LineBreak /> <Run>ContentControl - 其内包含有一个内容，继承自 Control。例：ScrollViewer, AppBar 等继承自 ContentControl</Run> <LineBreak /> <Run>ButtonBase - 按钮的基本功能，继承自 ContentControl。例：Button, RepeatButton 等继承自 ButtonBase</Run> <LineBreak /> <Run>ToggleButton - 可切换状态的按钮，继承自 ButtonBase。例：RadioButton, CheckBox 等继承自 ToggleButton</Run> <LineBreak /> <Run>RangeBase - 值在某一范围内，继承自 ButtonBase。例：ProgressBar, Slider, ScrollBar 等继承自 RangeBase</Run> <LineBreak /> <Run>ItemsControl - 用于呈现集合，继承自 Control</Run> <LineBreak /> <Run>Selector - 可选择集合中的某一项，继承自 ItemsControl。例：ComboBox, ListBox, FlipView, ListViewBase 等继承自 Selector</Run> <LineBreak /> <Run>ListViewBase - 继承自 ListViewBase 的控件有 GridView 和 ListView</Run> <LineBreak /> <Run>Panel - 一个容器，继承自 FrameworkElement。例：Grid, StackPanel, Canvas 等继承自 Panel</Run> <LineBreak /> <Run>如 ScrollBar, Thumb, RangeBase, ButtonBase, Selector, Popup 等这类基元控件在 Windows.UI.Xaml.Controls.Primitives 命名空间下</Run> </TextBlock> </StackPanel> </Grid> </Page>
5、路由事件和命中测试
Controls/Basic/RoutedEventDemo.xaml
<Page x:Class="XamlDemo.Controls.Basic.RoutedEventDemo" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:local="using:XamlDemo.Controls.Basic" xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" mc:Ignorable="d"> <Grid Background="Transparent"> <StackPanel Margin="120 0 0 0"> <Grid HorizontalAlignment="Left" VerticalAlignment="Top"> <!-- 演示事件冒泡：儿子传递事件给爸爸，爸爸传递事件给爷爷，这就是事件冒泡 --> <Border Name="borderRed" Background="Red" Width="300" Height="300"> <Border Name="borderGreen" Background="Green" Width="250" Height="250" Tapped="borderGreen_Tapped_1"> <Border Name="borderBlue" Background="Blue" Width="200" Height="200" Tapped="borderBlue_Tapped_1"> <Border Name="borderOrange" Background="Orange" Width="150" Height="150" Tapped="borderOrange_Tapped_1"> <!--命中测试不可见，也就是说 borderPurple 和 borderYellow 均命中测试不可见--> <Border Name="borderPurple" Background="Purple" Width="100" Height="100" Tapped="borderPurple_Tapped_1" IsHitTestVisible="False"> <Border Name="borderYellow" Background="Yellow" Width="50" Height="50" Tapped="borderYellow_Tapped_1" /> </Border> </Border> </Border> </Border> </Border> <!-- 像这样排列元素，是没有事件冒泡的，而只是前面的元素响应事件，后面的元素不会响应事件，也就是说同辈间没有事件冒泡的概念 IsHitTestVisible - 是否对命中测试可见 <Rectangle Name="rectangle1" Width="800" Height="400" Fill="Red" /> <Rectangle Name="rectangle2" Width="700" Height="350" Fill="Green" /> <Rectangle Name="rectangle3" Width="600" Height="300" Fill="Blue" /> <Rectangle Name="rectangle4" Width="500" Height="250" Fill="Orange" /> <Rectangle Name="rectangle5" Width="400" Height="200" Fill="Purple" /> --> </Grid> <TextBlock Name="lblMsg" FontSize="14.667" Margin="0 10 0 0" /> </StackPanel> </Grid> </Page>
Controls/Basic/RoutedEventDemo.xaml.cs
/* * 演示路由事件的冒泡和命中测试的可见性 * * TappedRoutedEventArgs * OriginalSource - 引发此路由事件的对象 * Handled - 是否将路由事件标记为已处理 * true - 不再冒泡 * false - 继续冒泡 * * UIElement * IsHitTestVisible - 是否对命中测试可见 */ using System; using Windows.UI.Xaml; using Windows.UI.Xaml.Controls; using Windows.UI.Xaml.Input; namespace XamlDemo.Controls.Basic { public sealed partial class RoutedEventDemo : Page { public RoutedEventDemo() { this.InitializeComponent(); // AddHandler() - 注册一个路由事件，注意最后一个参数：true 代表即使子辈 TappedRoutedEventArgs.Handled = true 也不会影响此元素事件的触发 // RemoveHandler() - 移除指定的路由事件 borderRed.AddHandler(UIElement.TappedEvent, new TappedEventHandler(borderRed_Tapped_1), true); } private void borderRed_Tapped_1(object sender, TappedRoutedEventArgs e) { lblMsg.Text += "borderRed tapped, originalSource: " + (e.OriginalSource as FrameworkElement).Name; lblMsg.Text += Environment.NewLine; } private void borderGreen_Tapped_1(object sender, TappedRoutedEventArgs e) { lblMsg.Text += "borderGreen tapped, originalSource: " + (e.OriginalSource as FrameworkElement).Name; lblMsg.Text += Environment.NewLine; } private void borderBlue_Tapped_1(object sender, TappedRoutedEventArgs e) { lblMsg.Text += "borderBlue tapped, originalSource: " + (e.OriginalSource as FrameworkElement).Name; lblMsg.Text += Environment.NewLine; // 不会再冒泡，也就是说 borderGreen 无法响应 Tapped 事件，但是 borderRed 注册 Tapped 事件时 handledEventsToo = true，所以 borderRed 会响应 Tapped 事件 e.Handled = true; } private void borderOrange_Tapped_1(object sender, TappedRoutedEventArgs e) { lblMsg.Text += "borderOrange tapped, originalSource: " + (e.OriginalSource as FrameworkElement).Name; lblMsg.Text += Environment.NewLine; } private void borderPurple_Tapped_1(object sender, TappedRoutedEventArgs e) { // 不会响应此事件，因为 borderPurple 的 IsHitTestVisible = false lblMsg.Text += "borderPurple tapped, originalSource: " + (e.OriginalSource as FrameworkElement).Name; lblMsg.Text += Environment.NewLine; } private void borderYellow_Tapped_1(object sender, TappedRoutedEventArgs e) { // 不会响应此事件，因为 borderYellow 的爸爸 borderPurple 的 IsHitTestVisible = false lblMsg.Text += "borderYellow tapped, originalSource: " + (e.OriginalSource as FrameworkElement).Name; lblMsg.Text += Environment.NewLine; } } }
OK
[源码下载]
