【WPF】日常笔记

本文专用于记录WPF开发中的小细节，作为备忘录使用。

1. 关于绑定：

Text ="{Binding AnchorageValue,Mode=TwoWay,UpdateSourceTrigger=PropertyChanged}"

2. 关于ListBox的样式

  //第一种
  <ListBox.ItemContainerStyle>
     <Style TargetType="{x:Type ListBoxItem}">
           <Style.Resources>
                   <SolidColorBrush x:Key="{x:Static SystemColors.HighlightBrushKey}" Color="Transparent" />
                   <SolidColorBrush x:Key="{x:Static SystemColors.HighlightTextBrushKey}" Color="Black" />
           </Style.Resources>
                   <Setter Property="FocusVisualStyle" Value="{x:Null}"/>
                   <Setter Property="HorizontalContentAlignment" Value="Stretch"/>
     </Style>
  </ListBox.ItemContainerStyle>

//第二种

<Style TargetType="ListBoxItem">
     <Style.Resources>
                  <!--SelectedItem with focus-->
       <SolidColorBrush x:Key="{x:Static SystemColors.HighlightBrushKey}" Color="#C7C7C7" />
       <!--SelectedItem without focus-->
       <SolidColorBrush x:Key="{x:Static SystemColors.ControlBrushKey}" Color="#C7C7C7" />
     </Style.Resources>
                 <!-- 设置触发器 -->
     <Style.Triggers>
       <Trigger Property="IsSelected" Value="true">
             <Setter Property="Background" Value="#C7C7C7"/>
             <Setter Property="Foreground" Value="Black"/>
       </Trigger>
       <Trigger Property="IsFocused" Value="true">
             <Setter Property="Background" Value="#C7C7C7"/>
             <Setter Property="Foreground" Value="Black"/>
       </Trigger>
     </Style.Triggers>
  </Style>

3. DataGrid数据添加折叠

Resource:

  <ResourceDictionary>
       <Style x:Key="GridGroupHeadStyle" TargetType="{x:Type GroupItem}">
             <Setter Property="Template">
                  <Setter.Value>
                        <ControlTemplate TargetType="{x:Type GroupItem}">
                            <Expander x:Name="GroupExpander" IsExpanded="True" >
                                <Expander.Header>
                                    <TextBlock Foreground="SlateBlue" FontSize="">
                                        <TextBlock.Text>
                                            <MultiBinding StringFormat="{}{0} ({1})">
                                                <Binding Path="Name"/>
                                                <Binding Path="ItemCount"/>
                                            </MultiBinding>
                                        </TextBlock.Text>
                                    </TextBlock>
                                </Expander.Header>
                                <ItemsPresenter />
                            </Expander>
                        </ControlTemplate>
                  </Setter.Value>
              </Setter>
        </Style>
   </ResourceDictionary>

   //还有一种样式：
   <ResourceDictionary>            
       <Style x:Key="GridGroupHeadStyle" TargetType="{x:Type GroupItem}">
           <Setter Property="Template">
                <Setter.Value>
                    <ControlTemplate TargetType="{x:Type GroupItem}">
                         <Expander x:Name="GroupExpander" IsExpanded="True">
                             <Expander.Style>
                                  <Style TargetType="{x:Type Expander}">
                                        <Setter Property="Background" Value="CornflowerBlue"/>
                                  </Style>
                             </Expander.Style>
                          <Expander.Header>
                                <TextBlock Foreground="Black"  FontWeight="ExtraBold" FontSize="12" Text="{Binding Path=Name}"/>
                          </Expander.Header>
                          <ItemsPresenter />
                       </Expander>
                   </ControlTemplate>
               </Setter.Value>
           </Setter>
         <Setter Property="Background" Value="Gainsboro"></Setter>
      </Style>
  </ResourceDictionary>

 //还有一种样式：
  <ResourceDictionary>
      <Style x:Key="GridGroupHeadStyle" TargetType="{x:Type GroupItem}">
             <Setter Property="Template">
                  <Setter.Value>
                        <ControlTemplate TargetType="{x:Type GroupItem}">
                            <Expander x:Name="GroupExpander" IsExpanded="True" FlowDirection="RightToLeft">
                                <Expander.Style>
                                    <Style TargetType="{x:Type Expander}">
                                        <Setter Property="Background" Value="CornflowerBlue"/>
                                    </Style>
                                </Expander.Style>
                                <Expander.HeaderTemplate>
                                    <DataTemplate>
                                        <TextBlock Text="{Binding RelativeSource={RelativeSource AncestorType=Expander}, Path=DataContext.Name}"
                                                   Width="{Binding RelativeSource={RelativeSource AncestorType=Expander}, Path=ActualWidth}" 
                                                   Margin="-30,0,0,0"
                                                   FlowDirection="LeftToRight">
                                        </TextBlock>
                                    </DataTemplate>
                                </Expander.HeaderTemplate>
                                <ItemsPresenter FlowDirection="LeftToRight"/>
                            </Expander>
                      </ControlTemplate>
                  </Setter.Value>
           </Setter>
       <Setter Property="Background" Value="Gainsboro"></Setter>
    </Style>
</ResourceDictionary>

DataGrid:  需要注意的是DataGrid的ItemsSource绑定的是ViewModel中的Groups而不是Info

<DataGrid.GroupStyle>
                <GroupStyle ContainerStyle="{StaticResource GridGroupHeadStyle}">
                    <GroupStyle.Panel>
                        <ItemsPanelTemplate>
                            <DataGridRowsPresenter/>
                        </ItemsPanelTemplate>
                    </GroupStyle.Panel>
                </GroupStyle>
 </DataGrid.GroupStyle>

ViewModel: 这里的PropertyGroupDescription填写的是你分组所依据的字段，并且是存在于<Model>中的。

public ObservableCollection<Model> Info { get; set; }

public ListCollectionView Groups { get; set; }

Groups = new ListCollectionView(Info);
Groups.GroupDescriptions.Add(new PropertyGroupDescription("Your Group Name"));

4. KeyboardNavigation.TabIndex

 <TextBlock
      Grid.Row=""
      Grid.Column=""
      VerticalAlignment="Center"
      Height="" Margin="0,17" KeyboardNavigation.TabIndex="" >
      <Hyperlink x:Name="registerHyperlink" Click="Hyperlink_Click" KeyboardNavigation.TabIndex="">
             <Run Text="点此注册"/>
      </Hyperlink>
 </TextBlock>

5. Button设置IsDefault=“true”则可以按Enter键触发这个按钮

6. DataGrid有些列需要ToolTip，最好的方法是重新Template。不建议DataGrid.CellStyle全部统一加上ToolTip，因为值所在列内容较短根本不需要ToolTip。

 <DataGridTemplateColumn Width="0.6*"  Header="设置名称" >
     <DataGridTemplateColumn.CellTemplate>
               <DataTemplate>
                  <TextBlock Text="{Binding Name}" ToolTip="{Binding Name}" FontSize="" VerticalAlignment="Center"/>
                </DataTemplate>
      </DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn>

7. 假设一个DataGrid的一列全是button，建议不在Model中去实现button的功能，而是在ViewModel中统一用一个命令去完成，界面上必须这样做：

Command命令为UninstallCmd，写在ViewModel里

<UserControl.Resources>
        <ResourceDictionary>
            <DataTemplate x:Key="btnTemplate">
                <Button Margin="" Content="卸载" Command="{Binding Path=DataContext.UninstallCmd,RelativeSource={RelativeSource Mode=FindAncestor,AncestorType=DataGrid}}" CommandParameter="{Binding Isbn}" />
            </DataTemplate>
        </ResourceDictionary>
</UserControl.Resources> 

<DataGrid Name="dataGrid" Grid.Row=""  Margin="5,5"
                  ItemsSource="{Binding Path=Isbns}"
                  Background="White"
                  AlternatingRowBackground="#EBEBEB"
                  SelectionMode="Single"
                  CanUserSortColumns="False"
                  CanUserAddRows="False"
                  AutoGenerateColumns="False"
                  CanUserReorderColumns="False"
                  CanUserResizeColumns="True" >

            <DataGrid.Columns>
                  <DataGridTemplateColumn Header="是否卸载" Width="Auto" CellTemplate="{StaticResource btnTemplate}"/>
            </DataGrid.Columns>
</DataGrid>

8. 在一些界面中使用PreviewMouseLeftButtonDown或者MouseLeftButtonDown会没有反应，这时候就只能使用PreviewMouseLeftButtonUp事件了。

 <i:Interaction.Triggers>
     <i:EventTrigger EventName="PreviewMouseLeftButtonUp">
        <i:InvokeCommandAction Command="{Binding ChangeDisplayCmd}"/>
     </i:EventTrigger>
</i:Interaction.Triggers>

9. DataGrid的ColumnHeader需要绑定整个界面ViewModel的某一个属性，而不是DataGrid.ItemsSource中的值：

下面这个例子的DataGridTextColumn的Header绑定的就是界面ViewModel的ColorConfig属性。

<DataGridTextColumn  Binding="{Binding SectionName}"  IsReadOnly="True" Width="Auto" ElementStyle="{StaticResource standardCell}" MinWidth="">
    <DataGridTextColumn.HeaderTemplate>
        <DataTemplate>
            <TextBlock Text="{Binding DataContext.ColorConfig, RelativeSource={RelativeSource AncestorType=DataGrid}}" VerticalAlignment="Center"/>
        </DataTemplate>
    </DataGridTextColumn.HeaderTemplate>
</DataGridTextColumn>

10. Image后台绑定时需要的是BitMapImage而不是简单的图片路径string，需要写Converter

//Xaml Code
<converters:MyConverter x:Key="MyImageConverter" FolderName="MyFolder"/>

<Image Grid.Row=""  VerticalAlignment="Stretch"  gif:ImageBehavior.AnimatedSource="{Binding MyImageSource, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged,Converter={StaticResource MyImageConverter}}"/>

  //Converter Code
  public class MyConverter : IValueConverter
  {
        public string FolderName { get; set; }
        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
        {
            if (value != null)
            {
                if (((string) value).Contains("SpecialText"))
                {
                    return new BitmapImage(new Uri(value as string, UriKind.Absolute));
                }
                else
                {
                    string uriString = $"pack://application:,,,/{Assembly.GetExecutingAssembly().GetName()};component/Resources/Image/{FolderName}/{value}";
                    return new BitmapImage(new Uri(uriString));
                }
            }
            return null;
        }
        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
        {
            return null;
        }
  }

11. Datagrid的水平及竖向网格都为虚线

 <DataGrid.HorizontalGridLinesBrush>
      <LinearGradientBrush StartPoint="0,0" EndPoint="3,0" MappingMode="Absolute" SpreadMethod="Repeat">
           <GradientStop Offset="" Color="Black"/>
           <GradientStop Offset="0.5" Color="Black"/>
           <GradientStop Offset="0.5" Color="Transparent"/>
           <GradientStop Offset="" Color="Transparent"/>
      </LinearGradientBrush>
 </DataGrid.HorizontalGridLinesBrush>
 <DataGrid.VerticalGridLinesBrush>
     <LinearGradientBrush StartPoint="0,0" EndPoint="0,3" MappingMode="Absolute" SpreadMethod="Repeat">
           <GradientStop Offset="" Color="Black"/>
           <GradientStop Offset="0.5" Color="Black"/>
           <GradientStop Offset="0.5" Color="Transparent"/>
           <GradientStop Offset="" Color="Transparent"/>
     </LinearGradientBrush>
 </DataGrid.VerticalGridLinesBrush>

12. 当ListBox自定义Template时我们会发现，点选ListBox会出现两个选中项，但是我们已经设置了ListBox的SelectionMode为Single。我们需要对ListBox的Template中的控件做一些Style设置：

<TextBox Grid.Column="" Width="" Height=""
         VerticalAlignment="Center"
         FontSize=""
         Text="{Binding LowestHeight,Mode=TwoWay,UpdateSourceTrigger=PropertyChanged}"
         TextChanged="LowHeight_TextChanged">

<TextBox.Style>
    <Style TargetType="{x:Type TextBox}">
        <Setter Property="IsHitTestVisible" Value="False" />
        <Style.Triggers>
              <DataTrigger
                    Binding="{Binding IsSelected, RelativeSource={RelativeSource FindAncestor,
                    AncestorType={x:Type ListBoxItem}, AncestorLevel=}}"
                    Value="True"><Setter Property="IsHitTestVisible" Value="True" />
              </DataTrigger>
        </Style.Triggers>
    </Style>
</TextBox.Style>                               

13.Button的Style如何重写才能有效

<Style x:Key="BtnStyle" TargetType="{x:Type Button}">
       <Setter Property="Control.Background" Value="Red"></Setter>
       <Setter Property="Control.Foreground" Value="White"></Setter>
       <Setter Property="Template">
       　　<Setter.Value>
              <ControlTemplate TargetType="{x:Type Button}">
                    <Grid Background="{TemplateBinding Background}">
                           <ContentPresenter x:Name="MyContentPresenter" Content="{TemplateBinding Content}" HorizontalAlignment="Center"  VerticalAlignment="Center" />
                    </Grid>
              </ControlTemplate>
     　　 </Setter.Value>
      </Setter>
</Style>