系列文章链接
- WPF进阶技巧和实战01-小技巧
- WPF进阶技巧和实战02-布局
- WPF进阶技巧和实战03-控件（1-控件及内容控件）
- WPF进阶技巧和实战03-控件（2-特殊容器）
- WPF进阶技巧和实战03-控件（5-列表、树、网格01）
- WPF进阶技巧和实战03-控件（5-列表、树、网格02）
- WPF进阶技巧和实战03-控件（5-列表、树、网格03）
- WPF进阶技巧和实战03-控件（5-列表、树、网格04）
- WPF进阶技巧和实战04-资源
- WPF进阶技巧和实战05-样式与行为
- WPF进阶技巧和实战06-控件模板
- WPF进阶技巧和实战07--自定义元素01
- WPF进阶技巧和实战07--自定义元素02
- WPF进阶技巧和实战08-依赖属性与绑定01
- WPF进阶技巧和实战08-依赖属性与绑定02
- WPF进阶技巧和实战08-依赖属性与绑定03
完善和扩展标准控件的方法：
- 样式：可使用样式方便地重用控件属性的集合，甚至可以使用触发器应用效果
- 内容控件：所有继承自ContentControl类的控件都支持嵌套的内容。使用内容控件，可以快速创建聚集其他元素的复合控件（按钮变成图像按钮，列表变成图像列表）
- 控件模板：所有WPF控件都是无外观的，这意味着他们具有硬编码的功能，但是他们的外观是通过控件模板单独定义的。使用新的控件模板替代默认模板，可重新构建基本控件
- 数据模板：所有派生自ItemsControl的类都支持数据模板，通过数据模板可创建某些数据对象的富列表显示。通过恰当的数据模板，可使用许多元素组合显示每个项，这些组合可以是文本，图像甚至是可编辑控件。
理解自定义元素
创建自定义元素需要继承的基类：
| 名称 | 说明 |
|---|---|
| FrameworkElement | 最低级的基类。只有当希望重写OnRender（）方法并使用DrawContext从头绘制内容时，才使用此方法 |
| Control | 当从头开始创建控件时，这是最常用的起点。该类是所有用户交互小组件的基类。Control类添加了用于设置背景、前景、字体和内容对齐方式等属性。控件类自身设置了Tab顺序，引入了鼠标双击功能（MouseDoubleClick和PreviewMouseDoubleClick事件），最重要的是定义了Template属性，为了无限灵活性，该属性允许使用自定义元素树替换其外观 |
| ContentControl | 这是能够显示任意单一内容控件的基类。显示的内容可以是元素或者结合使用模板的自定义对象（内容通过Content属性设置，并且可以通过ContentTemplate属性提供可选的模板）。 |
| UserControl | 这是可以用视图配置的内容控件。尽管用户控件和普通的内容控件是不同的，但是当希望对个窗口中快速重用用户界面中的不变模块时（而不是创建真正的能在不同应用程序之间转移的独立控件），通常使用该基类 |
| ItemsControl或Selector | 是封装列表类控件的基类，但是不支持选择。而Selector类是支持选择的控件更具体的基类。创建自定义控件不经常使用这些类，因为ListBox、ListView、TreeView控件的数据绑定特性提供了更大的灵活性 |
| Panel | 具有布局逻辑控件的基类。布局控件可以包含多个子元素，并根据特定的布局语义安排这些子元素。通常，面板提供了用于设置子元素的附加属性，配置如何安排子元素。 |
| Decorator | 封装其他元素的元素的基类，并且提供了一种图像效果或特定的功能。两个例子：Border、Viewbox。Border在元素周围绘制线条，Viewbox控件使用动态缩放其内容。 |
| 特殊控件类 | 如果希望改进现有控件，可以直接继承该控件。比如：可以创建基友内置验证逻辑的TextBox控件。 |
创建基本的用户控件
创建自定义颜色拾取器进行演示创建控件的各种重要概念。
定义依赖项属性
添加自定义用户控件之后，就是设计用户控件对外界公开的公共接口。也就是说，设计控件的使用者使用的与颜色拾取器进行交互的属性，方法和事件。
/// <summary>
/// ColorPicker.xaml 的交互逻辑
/// </summary>
public partial class ColorPicker : UserControl
{
public Color Color { get => (Color)GetValue(ColorProperty); set => SetValue(ColorProperty, value); }
public static readonly DependencyProperty ColorProperty = DependencyProperty.Register("Color", typeof(Color), typeof(ColorPicker), new FrameworkPropertyMetadata(Colors.Black, propertyChangedCallback: ColorChangedCallback));
private static void ColorChangedCallback(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
var colorPicker = (ColorPicker)d;
var colorNew = (Color)e.NewValue;
colorPicker.Red = colorNew.R;
colorPicker.Green = colorNew.G;
colorPicker.Blue = colorNew.B;
}
public byte Red { get => (byte)GetValue(RedProperty); set => SetValue(RedProperty, value); }
public static readonly DependencyProperty RedProperty = DependencyProperty.Register("Red", typeof(byte), typeof(ColorPicker), new FrameworkPropertyMetadata(0, propertyChangedCallback: ColorRGBChangedCallback));
public byte Green { get => (byte)GetValue(GreenProperty); set => SetValue(GreenProperty, value); }
public static readonly DependencyProperty GreenProperty = DependencyProperty.Register("Green", typeof(byte), typeof(ColorPicker), new FrameworkPropertyMetadata(0, propertyChangedCallback: ColorRGBChangedCallback));
public byte Blue { get => (byte)GetValue(BlueProperty); set => SetValue(BlueProperty, value); }
public static readonly DependencyProperty BlueProperty = DependencyProperty.Register("Blue", typeof(byte), typeof(ColorPicker), new FrameworkPropertyMetadata(0, propertyChangedCallback: ColorRGBChangedCallback));
private static void ColorRGBChangedCallback(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
var colorPicker = (ColorPicker)d;
var color = colorPicker.Color;
if (e.Property == RedProperty)
{
color.R = (byte)e.NewValue;
}
if (e.Property == GreenProperty)
{
color.G = (byte)e.NewValue;
}
if (e.Property == BlueProperty)
{
color.B = (byte)e.NewValue;
}
colorPicker.Color = color;
}
public ColorPicker()
{
InitializeComponent();
}
}
属性变化回调函数负责使Color属性与Red，Green，Blue属性保持一致。无论何时改变Red，Green，Blue属性时，都会调整Color属性。当设置Color属性时，也会更新Red，Green，Blue的值。上述代码不会引起一系列无休止的调用。WPF不允许重新进入属性变化回调函数。
定义路由事件
无论何时修改Color属性，不管是直接修改还是通过修改Red、Green、Blue成分，都会触发ColorChangedCallback事件，进而触发ColorChangedEvent路由事件。
//////////////////路由事件/////////////////
public static readonly RoutedEvent ColorChangedEvent = EventManager.RegisterRoutedEvent("ColorChanged", RoutingStrategy.Bubble, typeof(RoutedPropertyChangedEventHandler<Color>), typeof(ColorPicker));
public event RoutedPropertyChangedEventHandler<Color> ColorChanged
{
add { AddHandler(ColorChangedEvent, value); }
remove { RemoveHandler(ColorChangedEvent, value); }
}
private static void ColorChangedCallback(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
var colorPicker = (ColorPicker)d;
var colorNew = (Color)e.NewValue;
colorPicker.Red = colorNew.R;
colorPicker.Green = colorNew.G;
colorPicker.Blue = colorNew.B;
//触发路由事件
RoutedPropertyChangedEventArgs<Color> args = new RoutedPropertyChangedEventArgs<Color>((Color)e.OldValue, colorNew);
args.RoutedEvent = ColorPicker.ColorChangedEvent;
colorPicker.RaiseEvent(args);
}
添加标记
<UserControl
x:Class="Course05.ColorPicker"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Padding="5">
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*" />
<ColumnDefinition Width="Auto" />
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
</Grid.RowDefinitions>
<Slider x:Name="sliderRed" Grid.Row="0" Margin="{Binding Path=Padding, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type UserControl}, AncestorLevel=1}}" Maximum="255" Minimum="0" Value="{Binding Path=Red, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type UserControl}, AncestorLevel=1}}" />
<Slider x:Name="sliderGreen" Grid.Row="1" Margin="{Binding Path=Padding, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type UserControl}, AncestorLevel=1}}" Maximum="255" Minimum="0" Value="{Binding Path=Green, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type UserControl}, AncestorLevel=1}}" />
<Slider x:Name="sliderBlue" Grid.Row="2" Margin="{Binding Path=Padding, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type UserControl}, AncestorLevel=1}}" Maximum="255" Minimum="0" Value="{Binding Path=Blue, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type UserControl}, AncestorLevel=1}}" />
<Rectangle Grid.RowSpan="3" Grid.Column="1" Width="50" Stroke="Black" StrokeThickness="1">
<Rectangle.Fill>
<SolidColorBrush Color="{Binding Path=Color, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type UserControl}, AncestorLevel=1}}" />
</Rectangle.Fill>
</Rectangle>
</Grid>
</UserControl>
使用控件
<Window
x:Class="Course05.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:local="clr-namespace:Course05"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
Title="MainWindow"
Width="800"
Height="450"
mc:Ignorable="d">
<Grid>
<local:ColorPicker Width="500" Height="Auto" VerticalAlignment="Top" ColorChanged="ColorPicker_ColorChanged" Color="BurlyWood" />
<TextBlock x:Name="txtColor" Margin="0,200,0,0" HorizontalAlignment="Center" VerticalAlignment="Top" Text="TextBlock" TextWrapping="Wrap" />
</Grid>
</Window>
private void ColorPicker_ColorChanged(object sender, RoutedPropertyChangedEventArgs<Color> e)
{
if (e != null && this.txtColor != null)
txtColor.Text = e.NewValue.ToString();
}
命令支持
通过下面两种方法为自定义控件添加命令支持：
- 添加将控件链接到特定命令的命令绑定。通过这种方法，控件可以相应命令，而且不需要借助任何外部代码。
- 为命令创建新的RoutedUICommand对象，作为自定义控件的静态字段。然后为这个命令对象添加绑定。这种方法可使自定义控件支持没有在基本命令集合中定义命令。
public ColorPicker()
{
InitializeComponent();
SetupCommands();
}
private Color? previousColor;
private void SetupCommands()
{
CommandBinding binding = new CommandBinding(ApplicationCommands.Undo, UndoCommandExecuted, UndoCommandCanExecuted);
this.CommandBindings.Add(binding);
}
private void UndoCommandCanExecuted(object sender, CanExecuteRoutedEventArgs e)
{
e.CanExecute = previousColor.HasValue;
}
private void UndoCommandExecuted(object sender, ExecutedRoutedEventArgs e)
{
this.Color = this.previousColor.Value;
}
更可靠的命令，使用CommandManager.RegisterClassCommandBinding方法关联静态的命令处理程序。
CommandManager.RegisterClassCommandBinding(typeof(ColorPicker), new CommandBinding(ApplicationCommands.Undo, UndoCommandExecuted, UndoCommandCanExecuted));
private static void UndoCommandStatisCanExecuted(object sender, CanExecuteRoutedEventArgs e)
{
var colorPicker = (ColorPicker)sender;
e.CanExecute = colorPicker.previousColor.HasValue;
}
private static void UndoCommandStatisExecuted(object sender, ExecutedRoutedEventArgs e)
{
var colorPicker = (ColorPicker)sender;
colorPicker.Color = colorPicker.previousColor.Value;
}
深入分析用户控件
在后台，UserControl类的工作方式和父类ContentControl非常相似，只有下面几个区别：
- UserControl改变了一些默认值。将IsTabStop和Focusable属性设置为false，并将水平垂直对齐设置成Stretch，从而填充整个空间。
- UserControl类应用了一个新的控件模板，该模板由包含ContentPresenter元素的Border元素组成。
- UserControl类改变了路由事件的源。当事件从用户控件内的控件向以外的元素冒泡或者隧道路由时，事件源变为指向用户控件而不是原始元素。
从技术角度看，可改变用户控件的模板。实际上，只需要进行很少的调整，就可以将所有模板移到模板中。
创建无外观控件
创建无外观控件需要继承自控件基类，但是没有设计表面的控件。相反，这个控件将其标记到默认模板中，可替换模板而不会影响控件逻辑。
修改颜色提取器的代码
public class ColorPicker2 : System.Windows.Controls.Control
{
//////////////////依赖项属性/////////////////
public Color Color { get => (Color)GetValue(ColorProperty); set => SetValue(ColorProperty, value); }
public static readonly DependencyProperty ColorProperty = DependencyProperty.Register("Color", typeof(Color), typeof(ColorPicker2), new FrameworkPropertyMetadata(Colors.Black, propertyChangedCallback: ColorChangedCallback));
private static void ColorChangedCallback(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
var colorPicker = (ColorPicker2)d;
var colorNew = (Color)e.NewValue;
colorPicker.previousColor = (Color)e.OldValue;
colorPicker.Red = colorNew.R;
colorPicker.Green = colorNew.G;
colorPicker.Blue = colorNew.B;
//触发路由事件
RoutedPropertyChangedEventArgs<Color> args = new RoutedPropertyChangedEventArgs<Color>((Color)e.OldValue, colorNew);
args.RoutedEvent = ColorPicker2.ColorChangedEvent;
colorPicker.RaiseEvent(args);
}
public byte Red { get => (byte)GetValue(RedProperty); set => SetValue(RedProperty, value); }
public static readonly DependencyProperty RedProperty = DependencyProperty.Register("Red", typeof(byte), typeof(ColorPicker2), new FrameworkPropertyMetadata((byte)0, propertyChangedCallback: ColorRGBChangedCallback));
public byte Green { get => (byte)GetValue(GreenProperty); set => SetValue(GreenProperty, value); }
public static readonly DependencyProperty GreenProperty = DependencyProperty.Register("Green", typeof(byte), typeof(ColorPicker2), new FrameworkPropertyMetadata((byte)0, propertyChangedCallback: ColorRGBChangedCallback));
public byte Blue { get => (byte)GetValue(BlueProperty); set => SetValue(BlueProperty, value); }
public static readonly DependencyProperty BlueProperty = DependencyProperty.Register("Blue", typeof(byte), typeof(ColorPicker2), new FrameworkPropertyMetadata((byte)0, propertyChangedCallback: ColorRGBChangedCallback));
private static void ColorRGBChangedCallback(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
var colorPicker = (ColorPicker2)d;
var color = colorPicker.Color;
if (e.Property == RedProperty)
{
color.R = (byte)e.NewValue;
}
if (e.Property == GreenProperty)
{
color.G = (byte)e.NewValue;
}
if (e.Property == BlueProperty)
{
color.B = (byte)e.NewValue;
}
colorPicker.Color = color;
}
//////////////////路由事件/////////////////
public static readonly RoutedEvent ColorChangedEvent = EventManager.RegisterRoutedEvent("ColorChanged", RoutingStrategy.Bubble, typeof(RoutedPropertyChangedEventHandler<Color>), typeof(ColorPicker2));
public event RoutedPropertyChangedEventHandler<Color> ColorChanged
{
add { AddHandler(ColorChangedEvent, value); }
remove { RemoveHandler(ColorChangedEvent, value); }
}
public ColorPicker2()
{
SetupCommands();
DefaultStyleKeyProperty.OverrideMetadata(typeof(ColorPicker2), new FrameworkPropertyMetadata(typeof(ColorPicker2)));
}
private Color? previousColor;
private void SetupCommands()
{
CommandManager.RegisterClassCommandBinding(typeof(ColorPicker2), new CommandBinding(ApplicationCommands.Undo, UndoCommandStatisExecuted, UndoCommandStatisCanExecuted));
}
private static void UndoCommandStatisCanExecuted(object sender, CanExecuteRoutedEventArgs e)
{
var colorPicker = (ColorPicker2)sender;
e.CanExecute = colorPicker.previousColor.HasValue;
}
private static void UndoCommandStatisExecuted(object sender, ExecutedRoutedEventArgs e)
{
var colorPicker = (ColorPicker2)sender;
colorPicker.Color = colorPicker.previousColor.Value;
}
}
修改了继承类，去掉了构造函数的 InitializeComponent();方法，增加了通知WPF为控件提供新的样式。
修改颜色提取器的标记
增加颜色提取器的样式：
<Style TargetType="{x:Type local:ColorPicker2}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type local:ColorPicker2}">
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*" />
<ColumnDefinition Width="Auto" />
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
</Grid.RowDefinitions>
<Slider x:Name="sliderRed" Grid.Row="0" Margin="{TemplateBinding Padding}" Maximum="255" Minimum="0" Value="{Binding Path=Red, RelativeSource={RelativeSource Mode=TemplatedParent}}" />
<Slider x:Name="sliderGreen" Grid.Row="1" Margin="{TemplateBinding Padding}" Maximum="255" Minimum="0" Value="{Binding Path=Green, RelativeSource={RelativeSource Mode=TemplatedParent}}" />
<Slider x:Name="sliderBlue" Grid.Row="2" Margin="{TemplateBinding Padding}" Maximum="255" Minimum="0" Value="{Binding Path=Blue, RelativeSource={RelativeSource Mode=TemplatedParent}}" />
<Rectangle Grid.RowSpan="3" Grid.Column="1" Width="50" Stroke="Black" StrokeThickness="1">
<Rectangle.Fill>
<SolidColorBrush Color="{Binding Path=Color, RelativeSource={RelativeSource Mode=TemplatedParent}}" />
</Rectangle.Fill>
</Rectangle>
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
注意此处绑定的扩招，一部分使用TemplateBinding，一部分使用Binding（将RelativeSource设置为指向模板的父元素，也就是自定义控件），这两种形式原理基本一致。但是如果需要双向绑定或者绑定到继承自Freezable类的属性时（SolidColorBrush），模板绑定就失效了。
精简控件模板
- 添加部件名称
<Style TargetType="{x:Type local:ColorPicker3}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type local:ColorPicker3}">
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*" />
<ColumnDefinition Width="Auto" />
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
</Grid.RowDefinitions>
<Slider x:Name="PART_RedSlider" Grid.Row="0" Margin="{TemplateBinding Padding}" Maximum="255" Minimum="0" />
<Slider x:Name="PART_GreenSlider" Grid.Row="1" Margin="{TemplateBinding Padding}" Maximum="255" Minimum="0" />
<Slider x:Name="PART_BlueSlider" Grid.Row="2" Margin="{TemplateBinding Padding}" Maximum="255" Minimum="0" />
<Rectangle Grid.RowSpan="3" Grid.Column="1" Width="50" Stroke="Black" StrokeThickness="1">
<Rectangle.Fill>
<SolidColorBrush x:Name="PART_PreviewBrush" />
</Rectangle.Fill>
</Rectangle>
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
删除绑定，赋予名称，这些名称根据约定，都以PART_开头。
- 操作模板控件
重写方法OnApplyTemplate：
public override void OnApplyTemplate()
{
base.OnApplyTemplate();
{
RangeBase silder = GetTemplateChild("PART_RedSlider") as RangeBase;
if (silder != null)
{
Binding binding = new Binding("Red");
binding.Source = this;
binding.Mode = BindingMode.TwoWay;
silder.SetBinding(RangeBase.ValueProperty, binding);
}
}
{
RangeBase silder = GetTemplateChild("PART_GreenSlider") as RangeBase;
if (silder != null)
{
Binding binding = new Binding("Green");
binding.Source = this;
binding.Mode = BindingMode.TwoWay;
silder.SetBinding(RangeBase.ValueProperty, binding);
}
}
{
RangeBase silder = GetTemplateChild("PART_BlueSlider") as RangeBase;
if (silder != null)
{
Binding binding = new Binding("Blue");
binding.Source = this;
binding.Mode = BindingMode.TwoWay;
silder.SetBinding(RangeBase.ValueProperty, binding);
}
}
{
SolidColorBrush brush = GetTemplateChild("PART_PreviewBrush") as SolidColorBrush;
if (brush != null)
{
Binding binding = new Binding("Color");
binding.Source = brush;
binding.Mode = BindingMode.OneWayToSource;
this.SetBinding(ColorPicker3.ColorProperty, binding);
}
}
}
- 记录模板部件
[TemplatePart(Name = "PART_RedSlider", Type =typeof(RangeBase))]
[TemplatePart(Name = "PART_GreenSlider", Type = typeof(RangeBase))]
[TemplatePart(Name = "PART_BlueSlider", Type = typeof(RangeBase))]
[TemplatePart(Name = "PART_PreviewBrush", Type = typeof(SolidColorBrush))]
public class ColorPicker3 : System.Windows.Controls.Control
支持可视化状态
上面例子中的ColorPicker控件设计相对简单，是因为它不涉及状态（不具有焦点，鼠标是否在上面悬停，是否禁用状态来区分其可视化外观）。
下面的例子中FlipPanel，通过翻转效果来切换两种表面。可通过代码执行翻转（通过设置名为IsFlipped的属性），也可以使用一个便捷的按钮来翻转面板（除非控件使用者从模板中移除了此按钮）。控件模板需要制定两个独立部分：FlipPanel控件的前后内容区域。需要一个方法在两个状态之间切换：翻转状态和不翻转状态，可通过模板添加触发器来完成该工作。
- 开始编写FlipPanel类
public class FlipPanel : Control
{
public Object FrontContent { get => (Object)GetValue(FrontContentProperty); set => SetValue(FrontContentProperty, value); }
public static readonly DependencyProperty FrontContentProperty = DependencyProperty.Register("FrontContent", typeof(Object), typeof(FlipPanel), new FrameworkPropertyMetadata(null));
public Object BackContent { get => (Object)GetValue(BackContentProperty); set => SetValue(BackContentProperty, value); }
public static readonly DependencyProperty BackContentProperty = DependencyProperty.Register("BackContent", typeof(Object), typeof(FlipPanel), new FrameworkPropertyMetadata(null));
public bool IsFlipped { get => (bool)GetValue(IsFlippedProperty); set { SetValue(IsFlippedProperty, value); ChangeVisualStatus(true); } }
public static readonly DependencyProperty IsFlippedProperty = DependencyProperty.Register("IsFlipped", typeof(bool), typeof(FlipPanel), new FrameworkPropertyMetadata(false));
private void ChangeVisualStatus(bool isFlipped)
{
}
public CornerRadius CornerRadius { get => (CornerRadius)GetValue(CornerRadiusProperty); set => SetValue(CornerRadiusProperty, value); }
public static readonly DependencyProperty CornerRadiusProperty = DependencyProperty.Register("CornerRadius", typeof(CornerRadius), typeof(FlipPanel), null);
public FlipPanel()
{
DefaultStyleKeyProperty.OverrideMetadata(typeof(FlipPanel), new FrameworkPropertyMetadata(typeof(FlipPanel)));
}
}
默认样式的轮廓：
<Style TargetType="{x:Type local:FlipPanel}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type local:FlipPanel}">
<Grid>
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
- 选择部件和状态
FlipPanel需要两个状态：
- 正常状态：只有前面的内容可见，后面的内容被翻转、淡化或者被移出视图
- 翻转状态：只有后面的内容可见，前面的内容被动画移出视图
需要两个部件：
FlipButton：单击按钮时，视图从前面改到后面（或者从后面改到前面），FlipPanel通过处理按钮事件来提供该服务
FlipPanelAlternate：这是一个可选元素，与FlipButton的工作方式相同。允许控件使用者在自定义模板中使用两种不同的方法。一种选择时使用可翻转区域外的单个翻转按钮，另一种是选择在可翻转的两侧放置独立的翻转按钮。
[TemplateVisualState(Name = "Normal", GroupName = "ViewStatus")]
[TemplateVisualState(Name = "Flipped", GroupName = "ViewStatus")]
[TemplatePart(Name = "FlipButton", Type = typeof(ToggleButton))]
[TemplatePart(Name = "FlipButtonAlternate", Type = typeof(ToggleButton))]
public class FlipPanel : Control
- 默认控件模板
<Style TargetType="{x:Type local:FlipPanel}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type local:FlipPanel}">
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="Auto" />
<RowDefinition Height="Auto" />
</Grid.RowDefinitions>
<Border x:Name="FrontContent" Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" CornerRadius="{TemplateBinding CornerRadius}">
<ContentPresenter Content="{TemplateBinding FrontContent}" />
</Border>
<Border x:Name="BackContent" Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" CornerRadius="{TemplateBinding CornerRadius}">
<ContentPresenter Content="{TemplateBinding BackContent}" />
</Border>
<ToggleButton x:Name="FlipButton" Grid.Row="1" Width="20" Height="20" Margin="0,10,0,0" RenderTransformOrigin="0.5,0.5">
<ToggleButton.Template>
<ControlTemplate>
<Grid>
<Ellipse Fill="AliceBlue" Stroke="#FFA9A9A9" />
<Path HorizontalAlignment="Center" VerticalAlignment="Center" Data="M1,1.5L4.5,5 8,1.5" Stroke="#FF666666" StrokeThickness="2" />
</Grid>
</ControlTemplate>
</ToggleButton.Template>
<ToggleButton.RenderTransform>
<RotateTransform x:Name="FlipButtonTransform" Angle="-90" />
</ToggleButton.RenderTransform>
</ToggleButton>
<VisualStateManager.VisualStateGroups>
<VisualStateGroup x:Name="ViewStatus">
<VisualStateGroup.Transitions>
<VisualTransition GeneratedDuration="0:0:0.7" To="Flipped">
<Storyboard>
<DoubleAnimation Storyboard.TargetName="FlipButtonTransform" Storyboard.TargetProperty="Angle" To="90" Duration="0:0:0.2" />
</Storyboard>
</VisualTransition>
<VisualTransition GeneratedDuration="0:0:0.7" To="Normal">
<Storyboard>
<DoubleAnimation Storyboard.TargetName="FlipButtonTransform" Storyboard.TargetProperty="Angle" To="-90" Duration="0:0:0.2" />
</Storyboard>
</VisualTransition>
</VisualStateGroup.Transitions>
<VisualState x:Name="Normal">
<Storyboard>
<DoubleAnimation Storyboard.TargetName="BackContent" Storyboard.TargetProperty="Opacity" To="0" Duration="0" />
<DoubleAnimation Storyboard.TargetName="FrontContent" Storyboard.TargetProperty="Opacity" To="1" Duration="0" />
</Storyboard>
</VisualState>
<VisualState x:Name="Flipped">
<Storyboard>
<DoubleAnimation Storyboard.TargetName="FlipButtonTransform" Storyboard.TargetProperty="Angle" To="90" Duration="0" />
<DoubleAnimation Storyboard.TargetName="FrontContent" Storyboard.TargetProperty="Opacity" To="0" Duration="0" />
<DoubleAnimation Storyboard.TargetName="BackContent" Storyboard.TargetProperty="Opacity" To="1" Duration="0" />
</Storyboard>
</VisualState>
</VisualStateGroup>
</VisualStateManager.VisualStateGroups>
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
- 使用FlipPanel控件
<Grid >
<local:FlipPanel x:Name="panel" HorizontalAlignment="Left" Margin="128,33,0,0" VerticalAlignment="Top" Height="216" Width="536">
<local:FlipPanel.FrontContent>
<StackPanel>
<TextBlock Text="FrontContext"/>
</StackPanel>
</local:FlipPanel.FrontContent>
<local:FlipPanel.BackContent>
<StackPanel>
<TextBlock Text="BackContent"/>
<Button Content="123" Width="100" Height="20" Click="Button_Click"/>
</StackPanel>
</local:FlipPanel.BackContent>
</local:FlipPanel>
</Grid>
private void Button_Click(object sender, RoutedEventArgs e)
{
panel.IsFlipped = !panel.IsFlipped;
}
- 使用不同的控件模板
已经设计好的自定义控件极其灵活，可以使用新模板来修改ToggleButton按钮的外观和位置，并修改当在前后内容区域之间进行切换时应用的动画效果。