WPF 模型绑定-Binding

在 WPF 开发中会经常用到Binding,而绑定的数据源是变化的，有时候甚至数据源的结构也是变化的，View层设计多种模式，根据数据结构的变化呈现的内容和方式也会不同。下面演示一个小Demo,主要梳理一下动态改变Binding 的思路

• 模型

public class MyModel
{
     public string Label { get; set; }
     public string Value { get; set; }
}

• View

  <Window x:Class="WpfApp12.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:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:WpfApp12"
        mc:Ignorable="d"
        DataContext="{StaticResource model}"
        Title="MainWindow" Height="450" Width="800">
    <Grid>
        <Grid.RowDefinitions >
            <RowDefinition />
            <RowDefinition />
            <RowDefinition />
        </Grid.RowDefinitions>
        <TextBlock x:Name="tb" Text="{Binding Value}" Foreground="Red" FontSize="22" HorizontalAlignment="Center" VerticalAlignment="Center" />
       
        <StackPanel Grid.Row="1" HorizontalAlignment="Center" VerticalAlignment="Center" Orientation="Horizontal">
            <StackPanel.Resources>
                <Style TargetType="Button">
                    <Setter Property="Width" Value="100" />
                    <Setter Property="Height" Value="35" />
                    <EventSetter Event="Click" Handler="Button_Click" />
                </Style>
            </StackPanel.Resources>
            <Button Tag="btn1" Content="测试1" />
            <Button Tag="btn2" Content="测试2" />
        </StackPanel>
    </Grid>
</Window>

• Code

  public partial class MainWindow : Window
    {
        private Binding b1 = new Binding("Label");  //这里的Binding 对象和Path 路径是固定不变的
        private Binding b2 = new Binding("Value");
        private MyModel model;
        public MainWindow()
        {
            InitializeComponent();
            this.Loaded += MainWindow_Loaded;
            model = FindResource("model") as MyModel;
        }

        private void MainWindow_Loaded(object sender, RoutedEventArgs e)
        {
            b1.Source = model;
            b2.Source = model;
            model.Label = "This Is Label";
            model.Value = "My Is Value";
        }

        private void Button_Click(object sender, RoutedEventArgs e)
        {
                       
            string str = (sender as Button).Tag as string;
            if (str == "btn1") {
                
                tb.SetBinding(TextBlock.TextProperty, b1);  //这里绑定对象动态变化时

            }
            else if (str == "btn2")
            {
              
                tb.SetBinding(TextBlock.TextProperty, b2);
            }
            
        }
    }

• 配置文件

  <Application x:Class="WpfApp12.App"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:local="clr-namespace:WpfApp12"
             StartupUri="MainWindow.xaml">
    <Application.Resources>
        <ResourceDictionary>
          <local:MyModel x:Key="model" Value="值示例" Label="标签示例" />
        </ResourceDictionary>
    </Application.Resources>
</Application>