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  • WPF(五)元素绑定

      数据绑定是一种关系,WPF从一个源对象提取一些信息,并使用这些信息设置目标对象的属性。

    1.将元素绑定到一起

      例如:滑块的拖动,改变TextBlock字体的大小,如果不采用元素绑定,需要为Silder控件添加ValueChanged事件。下面的示例是简单的元素绑定。

      

        <Grid>
                <Slider Name="sliderFontSize" Margin="3" Minimum="1" Maximum="40" Value="10"
                    TickFrequency="1" TickPlacement="TopLeft">
                </Slider>
                <TextBlock Margin="10,39,10,62" Text="Simple Text" Name="lblSampleText" FontSize="{Binding ElementName=sliderFontSize,Path=Value}">
                </TextBlock>
            <Button Content="Set to Small" HorizontalAlignment="Left" Margin="36,149,0,0" VerticalAlignment="Top" Width="97"/>
            <Button Content="Set to Normal" HorizontalAlignment="Left" Margin="146,149,0,0" VerticalAlignment="Top" Width="105"/>
            <Button Content="Set to Large" HorizontalAlignment="Left" Margin="264,149,0,0" VerticalAlignment="Top" Width="85"/>
    
        </Grid>

    2.多绑定:

        <Grid Margin="5">
            <Grid.RowDefinitions>
                <RowDefinition Height="Auto"></RowDefinition>
                <RowDefinition Height="Auto"></RowDefinition>
                <RowDefinition Height="Auto"></RowDefinition>
                <RowDefinition Height="Auto"></RowDefinition>
                <RowDefinition></RowDefinition>
            </Grid.RowDefinitions>
            <Slider Name="sliderFontSize" Margin="3" Minimum="1" Maximum="40" Value="10"></Slider>
            <TextBox Name="txtContent" Margin="3" Grid.Row="2">Sample Content</TextBox>
            <ListBox Margin="3" Grid.Row="3" Name="lstColors">
                <ListBoxItem Tag="Blue">Blue</ListBoxItem>
                <ListBoxItem Tag="DarkBlue">Dark Blue</ListBoxItem>
                <ListBoxItem Tag="LightBlue">Light Blue</ListBoxItem>
            </ListBox>
            <TextBlock Margin="3" Name="lblSampleText"
                       FontSize="{Binding ElementName=sliderFontSize,Path=Value}" Grid.Row="4"
                       Text="{Binding ElementName=txtContent,Path=Text}"
                       Foreground="{Binding ElementName=lstColors,Path=SelectedItem.Tag}"
                       ></TextBlock>
        </Grid>

      双向绑定:

      

        <Grid>
            <Grid.RowDefinitions>
                <RowDefinition Height="Auto"></RowDefinition>
                <RowDefinition Height="*"></RowDefinition>
                <RowDefinition Height="Auto"></RowDefinition>
                <RowDefinition />
            </Grid.RowDefinitions>
            <Slider Name="sliderFontSize" Margin="3" Minimum="1" Maximum="40" Value="10" TickFrequency="1" IsSnapToTickEnabled="True" TickPlacement="TopLeft"></Slider>
            <TextBlock Grid.Row="1" Text="Simple Text" Margin="10" Name="lblSampleText"
                       FontSize="{Binding ElementName=sliderFontSize,Path=Value,Mode=TwoWay}"
                       ></TextBlock>
            <StackPanel Orientation="Horizontal" Margin="5" Grid.Row="2">
                <TextBlock VerticalAlignment="Center" xml:space="preserve">Exact Size:</TextBlock>
                <TextBox Text="{Binding ElementName=lblSampleText, Path=FontSize, UpdateSourceTrigger=PropertyChanged, Mode=TwoWay}" Width="100"></TextBox>
            </StackPanel>
        </Grid>

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  • 原文地址:https://www.cnblogs.com/WilliamJiang/p/2478368.html
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