8天入门wpf—— 第四天 模板

      今天说下wpf中的模板，前面一篇中我们讲到了style，但是style所能做的仅仅是在现有控件的基础上进行修修补补，但是如果我们想

彻底颠覆控件样式，那么我们就必须使用这一篇所说的模板。

   老外写书都喜欢在篇头搞一个类图，方便我们宏观认识，这里我也上一个。

一：控件模板

1：ControlTemplate

   我们知道wpf的控件都是继承自Control，在Control类中有一个Template属性，类型就是ControlTemplate。

那么利用这个ControlTemplate就可以彻底的颠覆控件的默认外观，这里我把一个checkbox变成一个小矩形，蛮有意思的。

 1 <Window x:Class="WpfApplication1.MainWindow" 2          xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 3          xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 4          xmlns:sys="clr-namespace:System;assembly=mscorlib" 5          Title="MainWindow" Height="350" Width="525"> 6     <Window.Resources> 7         <ControlTemplate x:Key="rect" TargetType="{x:Type CheckBox}"> 8             <StackPanel> 9                 <Rectangle Name="breakRectangle" Stroke="Red" StrokeThickness="2" Width="20" Height="20">10                     <Rectangle.Fill>11                         <SolidColorBrush Color="White"/>12                     </Rectangle.Fill>13                 </Rectangle>14             </StackPanel>15         </ControlTemplate>16     </Window.Resources>17     <Canvas>18         <CheckBox Template="{StaticResource ResourceKey=rect}" Content="我是CheckBox"/>19     </Canvas>20 </Window>

确实，我们干了一件漂亮的事情，把checkbox变成了“小矩形”，但是我们发现了一个小问题，为什么我的Content=“xxx”没有显示到模板上？

很简单，我们已经重定义了控件模板，默认模板将会被覆盖...

2：ContentPresenter

     幸好，wpf给我们提供了一个ContentPresenter，它的作用就是把原有模板的属性原封不动的投放到自定义模板中。

 1 <Window x:Class="WpfApplication1.MainWindow" 2          xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 3          xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 4          xmlns:sys="clr-namespace:System;assembly=mscorlib" 5          Title="MainWindow" Height="350" Width="525"> 6     <Window.Resources> 7         <ControlTemplate x:Key="rect" TargetType="{x:Type CheckBox}"> 8             <StackPanel> 9                 <Rectangle Name="breakRectangle" Stroke="Red" StrokeThickness="2" Width="20" Height="20">10                     <Rectangle.Fill>11                         <SolidColorBrush Color="White"/>12                     </Rectangle.Fill>13                 </Rectangle>14                 <ContentPresenter/>15             </StackPanel>16         </ControlTemplate>17     </Window.Resources>18     <Canvas>19         <CheckBox Template="{StaticResource ResourceKey=rect}" Content="我是CheckBox"/>20     </Canvas>21 </Window>

当然你也可以玩一些小技巧，比如我想在"矩形“和”文字”中间设置边距，那么我们可以设置ContentPresenter的margin。

 1 <Window x:Class="WpfApplication1.MainWindow" 2          xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 3          xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 4          xmlns:sys="clr-namespace:System;assembly=mscorlib" 5          Title="MainWindow" Height="350" Width="525"> 6     <Window.Resources> 7         <ControlTemplate x:Key="rect" TargetType="{x:Type CheckBox}"> 8             <StackPanel> 9                 <Rectangle Name="breakRectangle" Stroke="Red" StrokeThickness="2" Width="20" Height="20">10                     <Rectangle.Fill>11                         <SolidColorBrush Color="White"/>12                     </Rectangle.Fill>13                 </Rectangle>14                 <ContentPresenter Margin="10" />15             </StackPanel>16         </ControlTemplate>17     </Window.Resources>18     <Canvas>19         <CheckBox Template="{StaticResource ResourceKey=rect}"  Content="我是CheckBox"/>20     </Canvas>21 </Window>

如果你够聪明，你会发现我设置的margin是一个非常呆板的事情，意思就是说能不能根据具体控件灵活控制margin呢？答案肯定是没问题的，

因为我们记得一个控件可以绑定到另一个控件上，比如这里我将模板中的Margin绑定到原控件中的Padding上去。

 1 <Window x:Class="WpfApplication1.MainWindow" 2          xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 3          xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 4          xmlns:sys="clr-namespace:System;assembly=mscorlib" 5          Title="MainWindow" Height="350" Width="525"> 6     <Window.Resources> 7         <ControlTemplate x:Key="rect" TargetType="{x:Type CheckBox}"> 8             <StackPanel> 9                 <Rectangle Name="breakRectangle" Stroke="Red" StrokeThickness="2" Width="20" Height="20">10                     <Rectangle.Fill>11                         <SolidColorBrush Color="White"/>12                     </Rectangle.Fill>13                 </Rectangle>14                 <ContentPresenter Margin="{TemplateBinding Padding}" />15             </StackPanel>16         </ControlTemplate>17     </Window.Resources>18     <Canvas>19         <CheckBox Template="{StaticResource ResourceKey=rect}"  Content="我是CheckBox" Padding="10"/>20     </Canvas>21 </Window>

3：Trigger

     我们知道style里面也是有trigger的，废话不多说，上代码说话。

 1 <Window x:Class="WpfApplication1.MainWindow" 2          xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 3          xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 4          xmlns:sys="clr-namespace:System;assembly=mscorlib" 5          Title="MainWindow" Height="350" Width="525"> 6     <Window.Resources> 7         <ControlTemplate x:Key="rect" TargetType="{x:Type CheckBox}"> 8             <ControlTemplate.Resources> 9                 <SolidColorBrush x:Key="redBrush" Color="Red"/>10             </ControlTemplate.Resources>11             <StackPanel>12                 <Rectangle Name="breakRectangle" Stroke="Red" StrokeThickness="2" Width="20" Height="20">13                     <Rectangle.Fill>14                         <SolidColorBrush Color="White"/>15                     </Rectangle.Fill>16                 </Rectangle>17                 <ContentPresenter/>18             </StackPanel>19             <ControlTemplate.Triggers>20                 <Trigger Property="IsChecked" Value="True">21                     <Setter TargetName="breakRectangle" Property="Fill" Value="{StaticResource ResourceKey=redBrush}">22                     </Setter>23                 </Trigger>24             </ControlTemplate.Triggers>25         </ControlTemplate>26     </Window.Resources>27     <Canvas>28         <CheckBox Template="{StaticResource ResourceKey=rect}"  Content="我是CheckBox"/>29     </Canvas>30 </Window>

最后形成的效果就是当checkbox选中时为实心框，不选中为空心框。

4：与Style混搭

   可能刚才我也说了，style只能在原有的控件基础上修修补补，如果我们让Style修补Control控件的Template属性时，此时我们是不是

就可以实现ControlTemplate和Style的混搭呢？

 1 <Window x:Class="WpfApplication1.MainWindow" 2          xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 3          xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 4          xmlns:sys="clr-namespace:System;assembly=mscorlib" 5          Title="MainWindow" Height="350" Width="525"> 6     <Window.Resources> 7         <Style x:Key="cbx" TargetType="{x:Type CheckBox}"> 8             <Setter Property="Template"> 9                 <Setter.Value>10                     <ControlTemplate TargetType="{x:Type CheckBox}">11                         <ControlTemplate.Resources>12                             <SolidColorBrush x:Key="redBrush" Color="Red"/>13                         </ControlTemplate.Resources>14                         <StackPanel>15                             <Rectangle Name="breakRectangle" Stroke="Red" StrokeThickness="2" Width="20" Height="20">16                                 <Rectangle.Fill>17                                     <SolidColorBrush Color="White"/>18                                 </Rectangle.Fill>19                             </Rectangle>20                             <ContentPresenter/>21                         </StackPanel>22                         <ControlTemplate.Triggers>23                             <Trigger Property="IsChecked" Value="True">24                                 <Setter TargetName="breakRectangle" Property="Fill" Value="{StaticResource ResourceKey=redBrush}">25                                 </Setter>26                             </Trigger>27                         </ControlTemplate.Triggers>28                     </ControlTemplate>29                 </Setter.Value>30             </Setter>31         </Style>32 33     </Window.Resources>34     <Canvas>35         <CheckBox Style="{StaticResource ResourceKey=cbx}" Content="我是CheckBox"/>36     </Canvas>37 </Window>

二：数据模板

   现在我们已经知道“控件模板”是用于改变控件外观，那么“数据模板”顾名思义就是控制数据的显示方式，下面做个demo让person绑定到listbox上。

 1 namespace WpfApplication1 2 { 3     /// <summary> 4     /// MainWindow.xaml 的交互逻辑 5     /// </summary> 6     public partial class MainWindow : Window 7     { 8         public static string name = "一线码农"; 9 10         public MainWindow()11         {12             InitializeComponent();13         }14     }15 16     public class PersonList : ObservableCollection<Person>17     {18         public PersonList()19         {20             this.Add(new Person() { Name = "一线码农", Age = 24, Address = "上海" });21             this.Add(new Person() { Name = "小师妹", Age = 20, Address = "上海" });22         }23     }24 25     public class Person26     {27         public string Name { get; set; }28 29         public int Age { get; set; }30 31         public string Address { get; set; }32     }33 }

xaml：

 1 <Window x:Class="WpfApplication1.MainWindow" 2          xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 3          xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 4          xmlns:sys="clr-namespace:System;assembly=mscorlib" 5         xmlns:class="lazyload" src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB/AAffA0nNPuCLAAAAAElFTkSuQmCC" data-original="clr-namespace:WpfApplication1" 6          Title="MainWindow" Height="350" Width="525"> 7     <Window.Resources> 8         <ObjectDataProvider x:Key="personList" ObjectType="{x:Type src:PersonList}"/> 9     </Window.Resources>10     <Grid>11         <ListBox ItemsSource="{Binding Source={StaticResource ResourceKey=personList}}"></ListBox>12     </Grid>13 </Window>

最后我们发现，listbox中并没有呈现我们需要的数据，只是呈现了当前类的ToString()方法，很简单，因为我们绑定的不是简单的数据类型集合，

而是多字段的复杂类型，更重要的是我们并没有告诉wpf该如何呈现person数据。

<1>重写Tostring()

    既然wpf在Render数据的时候呈现的是当前的ToString()形式，那下面我们来重写ToString()试试看。

 1     public class Person 2     { 3         public string Name { get; set; } 4  5         public int Age { get; set; } 6  7         public string Address { get; set; } 8  9         public override string ToString()10         {11             return string.Format("姓名:{0}, 年龄:{1}, 地址:{2}", Name, Age, Address);12         }13     }

最后看看效果，如我们所愿，person信息已经呈现。

<2>DataTemplate重写

   或许有的人比较苛刻，他需要person是作为矩形一块一块的呈现，而不是这些简单的形式，那么此时我们就可以用DataTemplate来颠覆。

 1 <Window x:Class="WpfApplication1.MainWindow" 2          xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 3          xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 4          xmlns:sys="clr-namespace:System;assembly=mscorlib" 5         xmlns:class="lazyload" src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB/AAffA0nNPuCLAAAAAElFTkSuQmCC" data-original="clr-namespace:WpfApplication1" 6          Title="MainWindow" Height="350" Width="525"> 7     <Window.Resources> 8         <ObjectDataProvider x:Key="personList" ObjectType="{x:Type src:PersonList}"/> 9         <DataTemplate x:Key="rect">10             <Border Name="border" BorderBrush="Aqua" BorderThickness="1" Padding="5" Margin="5">11                 <StackPanel>12                     <StackPanel Orientation="Horizontal">13                         <TextBlock Text="{Binding Name}" Margin="5,0,0,0"/>14                         <TextBlock Text="{Binding Age}" Margin="5,0,0,0"/>15                     </StackPanel>16                     <StackPanel Orientation="Horizontal">17                         <TextBlock Text="{Binding Address}" Margin="5,0,0,0"/>18                     </StackPanel>19                 </StackPanel>20             </Border>21         </DataTemplate>22     </Window.Resources>23     <Grid>24         <ListBox ItemsSource="{Binding Source={StaticResource ResourceKey=personList}}"25                   ItemTemplate="{StaticResource ResourceKey=rect}"></ListBox>26     </Grid>27 </Window>

哈哈，果然是以一块一块的形式展现，大功告成，当然这里的”触发器“和”style混搭“跟ConrolTemplate非常相似，我想应该不需要累赘了。

三： ItemsPanelTemplate

      在条目控件（ItemControl)里面，有一个属性叫ItemPanel,类型是ItemPanelTemplate。

那么ItemsPanelTemplate主要用来干什么的呢？首先我们要知道常见的条目控件有：ListBox,Menu,StatusBar，比如拿ListBox来说，

我们经过仔细研究，发现ItemBox的ItemPanel其实是一个VisualizingStackPanel，就是说ListBox的每一项的排列方式是遵循StackPanel的

原则，也就是从上到下的排列方式，比如”一线码农“和”小师妹“是按照竖行排列方式，好，我现在的要求就是能够”横排“，该如何做到呢？

 1 <Window x:Class="WpfApplication1.MainWindow" 2          xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 3          xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 4          xmlns:sys="clr-namespace:System;assembly=mscorlib" 5         xmlns:class="lazyload" src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB/AAffA0nNPuCLAAAAAElFTkSuQmCC" data-original="clr-namespace:WpfApplication1" 6          Title="MainWindow" Height="350" Width="525"> 7     <Window.Resources> 8         <ObjectDataProvider x:Key="personList" ObjectType="{x:Type src:PersonList}"/> 9         <DataTemplate x:Key="rect">10             <Border Name="border" BorderBrush="Aqua" BorderThickness="1" Padding="5" Margin="5">11                 <StackPanel>12                     <StackPanel Orientation="Horizontal">13                         <TextBlock Text="{Binding Name}" Margin="5,0,0,0"/>14                         <TextBlock Text="{Binding Age}" Margin="5,0,0,0"/>15                     </StackPanel>16                     <StackPanel Orientation="Horizontal">17                         <TextBlock Text="{Binding Address}" Margin="5,0,0,0"/>18                     </StackPanel>19                 </StackPanel>20             </Border>21         </DataTemplate>22         <ItemsPanelTemplate x:Key="items">23             <StackPanel Orientation="Horizontal" VerticalAlignment="Center" HorizontalAlignment="Center"/>24         </ItemsPanelTemplate>25     </Window.Resources>26     <Grid>27         <ListBox ItemsSource="{Binding Source={StaticResource ResourceKey=personList}}"28                   ItemTemplate="{StaticResource ResourceKey=rect}" ItemsPanel="{StaticResource ResourceKey=items}"></ListBox>29     </Grid>30 </Window>

哈哈，确实有意思，我们改变了ListBox中Item的默认排序方向，当然在menu，statusBar中我们也可以用同样的方式来更改。

四： HierarchicalDataTemplate

       它是针对具有分层数据结构的控件设计的，比如说TreeView，相当于可以每一个层级上做DataTemplate，很好很强大。

 1 <Window x:Class="WpfApplication1.MainWindow" 2          xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 3          xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 4          xmlns:sys="clr-namespace:System;assembly=mscorlib" 5         xmlns:class="lazyload" src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB/AAffA0nNPuCLAAAAAElFTkSuQmCC" data-original="clr-namespace:WpfApplication1" 6          Title="MainWindow" Height="350" Width="525"> 7     <Window.Resources> 8         <XmlDataProvider x:Key="Info" XPath="Nations"> 9             <x:XData>10                 <Nations xmlns="">11                     <Nation Name="中国">12                         <Provinces>13                             <Province Name="安徽">14                                 <Citys>15                                     <City Name="安庆">16                                         <Countrys>17                                             <Country Name="潜山"/>18                                             <Country Name="桐城"/>19                                         </Countrys>20                                     </City>21                                     <City Name="合肥">22                                         <Countrys>23                                             <Country Name="长丰"/>24                                             <Country Name="肥东"/>25                                         </Countrys>26                                     </City>27                                 </Citys>28                             </Province>29                             <Province Name="江苏">30                                 <Citys>31                                     <City Name="南京">32                                         <Countys>33                                             <Country Name="溧水"/>34                                             <Country Name="高淳"/>35                                         </Countys>36                                     </City>37                                     <City Name="苏州">38                                         <Countys>39                                             <Country Name="常熟"/>40                                         </Countys>41                                     </City>42                                 </Citys>43                             </Province>44                         </Provinces>45                     </Nation>46                 </Nations>47             </x:XData>48         </XmlDataProvider>49         <HierarchicalDataTemplate DataType="Nation" ItemsSource="{Binding XPath=Provinces/Province}">50             <StackPanel Background="AliceBlue">51                 <TextBlock FontSize="20" Text="{Binding XPath=@Name}"/>52             </StackPanel>53         </HierarchicalDataTemplate>54         <HierarchicalDataTemplate DataType="Province" ItemsSource="{Binding XPath=Citys/City}">55             <StackPanel Background="LightBlue">56                 <TextBlock FontSize="18" Text="{Binding XPath=@Name}"/>57             </StackPanel>58         </HierarchicalDataTemplate>59         <HierarchicalDataTemplate DataType="City" ItemsSource="{Binding XPath=Countrys/Country}">60             <StackPanel Background="LightBlue">61                 <TextBlock FontSize="18" Text="{Binding XPath=@Name}"/>62             </StackPanel>63         </HierarchicalDataTemplate>64         <HierarchicalDataTemplate DataType="Country">65             <StackPanel Background="LightSalmon">66                 <TextBlock FontSize="18" Text="{Binding XPath=@Name}"/>67             </StackPanel>68         </HierarchicalDataTemplate>69     </Window.Resources>70     <TreeView ItemsSource="{Binding Source={StaticResource ResourceKey=Info},XPath=Nation}"></TreeView>71 </Window>