背水一战 Windows 10 (76) - 控件(控件基类): Control - 基础知识, 焦点相关, 运行时获取 ControlTemplate 和 D
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2022-03-18 14:05:47
背水一战 Windows 10 之 控件(控件基类 - Control): 基础知识, 焦点相关, 运行时获取 ControlTemplate 和 DataTemplate 中的元素 ......
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作者:webabcd
介绍
背水一战 Windows 10 之 控件(控件基类 - Control)
示例
1、演示 Control 的基础知识
Controls/BaseControl/ControlDemo/Demo1.xaml
<Page x:Class="Windows10.Controls.BaseControl.ControlDemo.Demo1" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:local="using:Windows10.Controls.BaseControl.ControlDemo" xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" mc:Ignorable="d"> <Grid Background="Orange"> <TextBox Name="textBox" Text="i am webabcd" TextWrapping="Wrap" AcceptsReturn="True" Margin="100" /> </Grid> </Page>
Controls/BaseControl/ControlDemo/Demo1.xaml.cs
/* * Control - Control(继承自 UIElement, 请参见 /Controls/BaseControl/FrameworkElementDemo/) * Background - 背景 Brush * Foreground - 前景 Brush * BorderBrush - 边框 Brush * BorderThickness - 边框 Thickness * Padding - Padding * FontSize - 字号大小(单位:像素) * FontFamily - 首选字体,多个用“,”分隔,找不到第 1 个就用第 2 个,找不到第 2 个就用第 3 个,以此类推 * FontStretch - 字体的拉伸值(FontStretch 枚举),默认值是 Normal(大部分字体都不支持这个属性) * FontStyle - 字体样式(FontStyle 枚举) * Normal - 默认值 * Italic - 使用字体自带的斜体 * Oblique - 通过程序让正常字体倾斜(对于自身不带斜体的字体可以使用此值让字体倾斜) * FontWeight - 字体粗细(FontWeights 实体类),默认值是 Normal * CharacterSpacing - 用于设置字符间距 * 具体字符间隔像素计算公式如下:字体大小 * CharacterSpacing值 / 1000 = 字符间距像素值 * IsTextScaleFactorEnabled - 是否启用文本自动放大功能(默认值是 true) * 在“设置”->“轻松使用”中可以调整文本缩放大小,IsTextScaleFactorEnabled 就是用于决定 TextBlock 显示的文本是否跟着这个设置走 * HorizontalContentAlignment - 内容的水平对齐方式 * VerticalContentAlignment - 内容的垂直对齐方式 * IsEnabled - 是否可用 * IsEnabledChanged - IsEnabled 属性的值发生变化时触发的事件 * Template - 控件模板,参见 /Controls/UI/ControlTemplate.xaml * * * 本例用于演示 Control 的基础知识 */ using System; using Windows.UI; using Windows.UI.Xaml; using Windows.UI.Xaml.Controls; using Windows.UI.Xaml.Media; using Windows.UI.Xaml.Media.Imaging; using Windows.UI.Text; namespace Windows10.Controls.BaseControl.ControlDemo { public sealed partial class Demo1 : Page { public Demo1() { this.InitializeComponent(); this.Loaded += Demo1_Loaded; } private void Demo1_Loaded(object sender, RoutedEventArgs e) { ImageBrush imageBrush = new ImageBrush(); imageBrush.ImageSource = new BitmapImage(new Uri("ms-appx:///Assets/hololens.jpg", UriKind.Absolute)); imageBrush.Stretch = Stretch.Fill; textBox.Background = imageBrush; // 关于各种类型的 Brush 请参见 /Drawing/Brush.xaml textBox.Foreground = new SolidColorBrush(Colors.DarkGreen); textBox.BorderBrush = new SolidColorBrush(Colors.Red); textBox.BorderThickness = new Thickness(0, 0, 0, 100); // 边框的占用空间是完全是在 Control 内部的 textBox.Padding = new Thickness(20); textBox.FontSize = 24; textBox.FontFamily = new FontFamily("微软雅黑,宋体"); textBox.FontStretch = FontStretch.Normal; textBox.FontStyle = FontStyle.Normal; textBox.FontWeight = FontWeights.Normal; textBox.CharacterSpacing = 100; textBox.IsTextScaleFactorEnabled = true; // 对于 TextBox 来说 HorizontalContentAlignment 和 VerticalContentAlignment 都是无效的 // 但是对于 Button 来说则可以通过 HorizontalContentAlignment 和 VerticalContentAlignment 来指定按钮上文字的对齐方式 textBox.HorizontalContentAlignment = HorizontalAlignment.Center;// 无效,如果需要设置文字内容的水平对齐方式的话请使用 textBox.TextAlignment textBox.VerticalContentAlignment = VerticalAlignment.Center; // 无效 textBox.IsEnabledChanged += TextBox_IsEnabledChanged; textBox.IsEnabled = false; // 注:如果要修 IsEnabled = false 的样式请查看名为 Disabled 的 VisualState textBox.IsEnabled = true; } private void TextBox_IsEnabledChanged(object sender, DependencyPropertyChangedEventArgs e) { textBox.Text += Environment.NewLine; textBox.Text += $"textBox.IsEnabled, OldValue:{e.OldValue}, NewValue:{e.NewValue}"; } } }
2、演示 Control 的焦点相关的知识点
Controls/BaseControl/ControlDemo/Demo2.xaml
<Page x:Class="Windows10.Controls.BaseControl.ControlDemo.Demo2" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:local="using:Windows10.Controls.BaseControl.ControlDemo" xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" mc:Ignorable="d"> <Grid Background="Orange"> <StackPanel Name="stackPanel" Background="Blue" Margin="100"> <!-- 用于演示 TabIndex 和 IsTabStop --> <TextBox Name="textBox1" TabIndex="5" Margin="5" /> <TextBox Name="textBox2" TabIndex="3" Margin="5" /> <TextBox Name="textBox3" IsTabStop="False" TabIndex="4" Margin="5" /> <TextBox Name="textBox4" TabIndex="1" Margin="5" /> <TextBox Name="textBox5" TabIndex="2" Margin="5" /> <ComboBox Name="cmbTabNavigation" PlaceholderText="HorizontalAlignment" IsTabStop="False" SelectionChanged="cmbTabNavigation_SelectionChanged" Margin="5"> <ComboBoxItem IsSelected="True">Local</ComboBoxItem> <ComboBoxItem>Cycle</ComboBoxItem> <ComboBoxItem>Once</ComboBoxItem> </ComboBox> <!-- 用于演示 TabNavigation 1、Local - 当 focus 至 itemsControl 时,会逐一 focus 其内部的所有 Control 元素,然后退出 focus 2、Cycle - 当 focus 至 itemsControl 时,会逐一 focus 其内部的所有 Control 元素,然后再继续无限循环 focus 其内部的所有 Control 元素 3、Once - 当 focus 至 itemsControl 时,只会 focus 其内部的第一个 Control 元素,然后退出 focus --> <ItemsControl Name="itemsControl" Margin="5" HorizontalAlignment="Left"> <ItemsControl.Items> <TextBox /> <TextBox /> <TextBox /> </ItemsControl.Items> </ItemsControl> <!-- 用于演示 UseSystemFocusVisuals 1、UseSystemFocusVisuals="False" 获取焦点后,不会有任何效果,如果需要自定义获取焦点后的效果的话请在控件模板中设置 2、UseSystemFocusVisuals="True" 获取焦点后,由系统绘制效果(我这里测试的效果是,有一个虚线的边框显示) --> <Button Content="i am button 1" UseSystemFocusVisuals="False" Margin="5" /> <Button Content="i am button 2" UseSystemFocusVisuals="True" Margin="5" /> <Button Content="i am button 3" UseSystemFocusVisuals="False" Margin="5"> <Button.Template> <ControlTemplate TargetType="Button"> <Grid x:Name="RootGrid" Background="{TemplateBinding Background}"> <VisualStateManager.VisualStateGroups> <VisualStateGroup x:Name="FocusStates"> <VisualState x:Name="Focused"> <VisualState.Setters> <Setter Target="border.BorderThickness" Value="5" /> </VisualState.Setters> </VisualState> <VisualState x:Name="Unfocused" /> <VisualState x:Name="PointerFocused" /> </VisualStateGroup> </VisualStateManager.VisualStateGroups> <Border x:Name="border" BorderBrush="Red" BorderThickness="0"> <ContentPresenter x:Name="ContentPresenter" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Content="{TemplateBinding Content}" ContentTransitions="{TemplateBinding ContentTransitions}" ContentTemplate="{TemplateBinding ContentTemplate}" Padding="{TemplateBinding Padding}" HorizontalContentAlignment="{TemplateBinding HorizontalContentAlignment}" VerticalContentAlignment="{TemplateBinding VerticalContentAlignment}" AutomationProperties.AccessibilityView="Raw"/> </Border> </Grid> </ControlTemplate> </Button.Template> </Button> <!-- IsTemplateFocusTarget - 是否是控件内用于获取焦点的元素(附加属性) --> <Button Content="i am button 4" Margin="5"> <Button.Template> <ControlTemplate TargetType="Button"> <Grid x:Name="RootGrid" Background="{TemplateBinding Background}"> <Border x:Name="border" BorderBrush="Red" BorderThickness="0"> <StackPanel> <ContentPresenter x:Name="ContentPresenter" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Content="{TemplateBinding Content}" ContentTransitions="{TemplateBinding ContentTransitions}" ContentTemplate="{TemplateBinding ContentTemplate}" Padding="{TemplateBinding Padding}" HorizontalContentAlignment="{TemplateBinding HorizontalContentAlignment}" VerticalContentAlignment="{TemplateBinding VerticalContentAlignment}" AutomationProperties.AccessibilityView="Raw"/> <!-- Control.IsTemplateFocusTarget="True" - 代表此 Button 控件用于获取焦点的元素是此 TextBlock --> <TextBlock Control.IsTemplateFocusTarget="True" Text="IsTemplateFocusTarget" /> </StackPanel> </Border> </Grid> </ControlTemplate> </Button.Template> </Button> </StackPanel> </Grid> </Page>
Controls/BaseControl/ControlDemo/Demo2.xaml.cs
/* * Control - Control(继承自 UIElement, 请参见 /Controls/BaseControl/FrameworkElementDemo/) * FocusState - 当前的焦点状态(FocusState 枚举) * Unfocused - 无焦点 * Pointer - 通过指针获取的焦点 * Keyboard - 通过键盘获取的焦点 * Programmatic - 通过 api 获取的焦点 * bool Focus(FocusState value) - 设置焦点状态 * TabIndex - Tab 键导航顺序(按 tab 键正序导航;按 shift + tab 键倒序导航),默认值为 int.MaxValue * IsTabStop - 是否包含在 Tab 导航中(即是否可获取到焦点) * TabNavigation - Tab 键导航至 Control 内部时的效果 * Local - 当 focus 至 Control 时,会逐一 focus 此 Control 内部的所有 Control 元素,然后退出 focus * Cycle - 当 focus 至 Control 时,会逐一 focus 此 Control 内部的所有 Control 元素,然后再继续无限循环 focus 此 Control 内部的所有 Control 元素 * Once - 当 focus 至 Control 时,只会 focus 此 Control 内部的第一个 Control 元素,然后退出 focus * UseSystemFocusVisuals - 是否使用系统的焦点效果 * false - 在控件模板中设置焦点效果 * true - 使用系统的焦点效果(我这里测试的效果是,获取焦点后会显示一个虚线边框) * IsTemplateFocusTarget - 是否是控件内用于获取焦点的元素(附加属性) * GotFocus - 获取焦点时触发的事件(来自 UIElement) * LostFocus - 丢失焦点时触发的事件(来自 UIElement) * * * 本例用于演示 Control 的焦点相关的知识点 */ using System; using Windows.UI.Xaml; using Windows.UI.Xaml.Controls; using Windows.UI.Xaml.Input; namespace Windows10.Controls.BaseControl.ControlDemo { public sealed partial class Demo2 : Page { public Demo2() { this.InitializeComponent(); this.Loaded += Demo2_Loaded; } private void Demo2_Loaded(object sender, RoutedEventArgs e) { textBox1.GotFocus += TextBox1_GotFocus; textBox2.GotFocus += TextBox2_GotFocus; textBox3.GotFocus += TextBox3_GotFocus; textBox4.GotFocus += TextBox4_GotFocus; textBox5.GotFocus += TextBox5_GotFocus; } private void TextBox1_GotFocus(object sender, RoutedEventArgs e) { textBox1.Text += textBox1.FocusState; } private void TextBox2_GotFocus(object sender, RoutedEventArgs e) { textBox2.Text += textBox2.FocusState; } private void TextBox3_GotFocus(object sender, RoutedEventArgs e) { textBox3.Text += textBox3.FocusState; } private void TextBox4_GotFocus(object sender, RoutedEventArgs e) { textBox4.Text += textBox4.FocusState; } // 这里当 textBox5 获取到焦点时,立刻指定 textBox2 获取焦点,则会达到禁止 textBox5 获取焦点的同时手动指定下一个焦点对象 // 如果只是禁止获取焦点的话可以设置 IsTabStop 为 false private void TextBox5_GotFocus(object sender, RoutedEventArgs e) { textBox5.Text += textBox5.FocusState; // 设置为 FocusState.Unfocused 时会抛异常 bool success = textBox2.Focus(FocusState.Programmatic); } private void cmbTabNavigation_SelectionChanged(object sender, SelectionChangedEventArgs e) { if (itemsControl != null) { itemsControl.TabNavigation = (KeyboardNavigationMode)Enum.Parse(typeof(KeyboardNavigationMode), (e.AddedItems[0] as ComboBoxItem).Content.ToString()); } } } }
3、演示如何在运行时获取 ControlTemplate 和 DataTemplate 中的元素
Controls/BaseControl/ControlDemo/Demo3.xaml
<Page x:Class="Windows10.Controls.BaseControl.ControlDemo.Demo3" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:local="using:Windows10.Controls.BaseControl.ControlDemo" xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" mc:Ignorable="d" xmlns:common="using:Windows10.Common"> <Page.Resources> <!-- ControlTemplate - 控件模板(是 xaml 语言使用的一种方案,其无法在 c# 中定义) --> <ControlTemplate x:Key="MyControlTemplate" TargetType="ContentControl"> <Grid x:Name="grid"> <ContentPresenter ContentTemplate="{TemplateBinding ContentTemplate}" ContentTransitions="{TemplateBinding ContentTransitions}" Content="{TemplateBinding Content}" HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" Margin="{TemplateBinding Padding}" VerticalAlignment="{TemplateBinding VerticalContentAlignment}"/> </Grid> </ControlTemplate> <!-- DataTemplate - 数据模板(是 xaml 语言使用的一种方案,其无法在 c# 中定义) --> <DataTemplate x:DataType="common:Employee" x:Key="MyDataTemplate"> <TextBlock x:Name="textBlock" Text="{x:Bind Name}" /> </DataTemplate> </Page.Resources> <Grid Background="Transparent"> <StackPanel Margin="10 0 10 10"> <local:MyContentControl x:Name="myContentControl" DataContext="{x:Bind CurrentEmployee}" Template="{StaticResource MyControlTemplate}" ContentTemplate="{StaticResource MyDataTemplate}" /> </StackPanel> </Grid> </Page>
Controls/BaseControl/ControlDemo/Demo3.xaml.cs
/* * Control - Control(继承自 UIElement, 请参见 /Controls/BaseControl/FrameworkElementDemo/) * GetTemplateChild() - 查找控件模板中的指定名字的元素 * OnApplyTemplate() - 应用控件模板时调用(来自 FrameworkElement) * * VisualTreeHelper - 可视化树的实用工具类 * * * 本例用于演示如何在运行时获取 ControlTemplate 和 DataTemplate 中的元素 */ using Windows.UI; using Windows.UI.Xaml; using Windows.UI.Xaml.Controls; using Windows.UI.Xaml.Media; using Windows10.Common; namespace Windows10.Controls.BaseControl.ControlDemo { public sealed partial class Demo3 : Page { public Employee CurrentEmployee { get; set; } = new Employee() { Name = "wanglei", Age = 36, IsMale = true }; public Demo3() { this.InitializeComponent(); myContentControl.Loaded += MyContentControl_Loaded; } private void MyContentControl_Loaded(object sender, RoutedEventArgs e) { // 通过 VisualTreeHelper 获取可视化树结构(借此可以获取数据模板中的元素) TextBlock textBlock = Helper.GetVisualChild<TextBlock>(myContentControl, "textBlock"); textBlock.FontSize = 48; } } public class MyContentControl : ContentControl { // override OnApplyTemplate() - 应用控件模板时调用 protected override void OnApplyTemplate() { base.OnApplyTemplate(); // 在 OnApplyTemplate() 中通过 GetTemplateChild() 获取控件模板中的指定名字的元素 Grid grid = (Grid)GetTemplateChild("grid"); grid.Background = new SolidColorBrush(Colors.Orange); } } }
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