绑定就是Binding，是控件和数据之间交互的类。
source = {binding}
和
source = {binding RelativeSource={RelativeSource self},Path=DataContext}
效果相同。
例如：直接绑定数据源
前台xaml界面
<Grid>
<StackPanel Orientation="Vertical">
<TextBlock Text="{Binding Number}" Width="50" Height="30" Background="WhiteSmoke" Foreground="Black"/>
<TextBlock Text="{Binding Name}" Width="50" Height="30" Background="WhiteSmoke" Foreground="Black"/>
<TextBlock Text="{Binding Class}" Width="50" Height="30" Background="WhiteSmoke" Foreground="Black"/>
</StackPanel>
</Grid>
public partial class MainWindow : Window
{
public class StudentInfo
{
public int Number { get; set; }
public string Name { get; set; }
public string Class { get; set; }
}
public MainWindow()
{
InitializeComponent();
List<StudentInfo> list = new List<StudentInfo>();
for (int i = 0; i < 10; i++)
{
StudentInfo entity1 = new StudentInfo();
entity1.Number = i;
entity1.Name = "其他" + i;
entity1.Class = "其他" + i + "其他";
list.Add(entity1);
}
this.DataContext = list;
}
}
这里最重要的是this.DataContext = list; 不同的时候DataContext 是不一样的
其中RelativeSource有4种模式：
1.RelativeSource Mode=Self，绑定自身的值。
2.RelativeSource Mode=PreviousData，么看懂，反正就是最后一行数据少了（***），图如下
3.TemplatedParent模式，绑定一个模板。
4.FindAncestor模式，绑定特定的类型。
绑定有三种，Binding，PriorityBinding，MultiBinding。
第一种，Binding，单个值绑定
2个控件一旦进行绑定，那么2个控件是相互的，你变化，我也跟着变化。
1.当绑定写在第一个控件上
<StackPanel>
<Slider x:Name="s" Value="{Binding ElementName=t, Path=Text}"></Slider>
<TextBox x:Name="t" Text="0"></TextBox>
<!--<Slider x:Name="s" Value="0"></Slider>
<TextBox x:Name="t" Text="{Binding ElementName=s, Path=Value,UpdateSourceTrigger=PropertyChanged}"></TextBox>-->
</StackPanel>
2.当绑定写在第二个控件上
<StackPanel>
<!--<Slider x:Name="s" Value="{Binding ElementName=t, Path=Text}"></Slider>
<TextBox x:Name="t" Text="0"></TextBox>-->
<Slider x:Name="s" Value="0"></Slider>
<TextBox x:Name="t" Text="{Binding ElementName=s, Path=Value,UpdateSourceTrigger=PropertyChanged}"></TextBox>
</StackPanel>
<Window x:Class="Dispatcher.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:Dispatcher" xmlns:collection="clr-namespace:System.Collections;assembly=mscorlib" xmlns:sys="clr-namespace:System;assembly=mscorlib"
mc:Ignorable="d"
Title="MainWindow" Height="450" Width="800">
<Window.Resources>
<local:AsyncDataSource x:Key="AsyncDS" SlowestDP="最慢" SlowerDP="慢" FastDP="快" />
</Window.Resources>
<Grid>
<StackPanel HorizontalAlignment="Center" VerticalAlignment="Center" DataContext="{Binding Source={StaticResource AsyncDS}}">
<TextBlock FontSize="18" FontWeight="Bold" Margin="10" HorizontalAlignment="Center">Priority Binding</TextBlock>
<TextBlock Background="Honeydew" Width="100" HorizontalAlignment="Center">
<TextBlock.Text>
<PriorityBinding FallbackValue="defaultvalue">
<Binding Path="SlowestDP" IsAsync="True"/>
<Binding Path="SlowerDP" IsAsync="True"/>
<Binding Path="FastDP" />
</PriorityBinding>
</TextBlock.Text>
</TextBlock>
</StackPanel>
</Grid>
</Window>
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
namespace Dispatcher
{
public class AsyncDataSource
{
private string _fastDP;
private string _slowerDP;
private string _slowestDP;
public AsyncDataSource()
{
}
public string FastDP
{
get { return _fastDP; }
set { _fastDP = value; }
}
public string SlowerDP
{
get
{
Thread.Sleep(3000); //模拟耗时
return _slowerDP;
}
set { _slowerDP = value; }
}
public string SlowestDP
{
get
{
Thread.Sleep(5000); //模拟耗时
return _slowestDP;
}
set { _slowestDP = value; }
}
}
}
第三种，MultiBinding
值转换分为单值转换IValueConverter和多值转换IMultiValueConverter。
使用值转化类可以简单轻松的解决前台界面显示数据的变化，解决同一种数据多种表示的难题。
一、单值转换IValueConverter
1.首先建立一个转换类，引用using System.Windows.Data;，然后继承IValueConverter，点击实现接口
class YesNoToConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
//value就是前台传递过来的值
switch (value.ToString().ToLower())
{
case "y":
case "ye":
case "yes":
return true;
case "n":
case "no":
case "non":
return false;
}
return false;
}
public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
{
if (value is bool)
{
if ((bool)value == true)
return "yes";
else
return "no";
}
return "no";
}
}
<Window x:Class="WpfApp2.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:WpfApp2"
mc:Ignorable="d"
Title="MainWindow" Height="450" Width="800">
<Window.Resources>
<local:YesNoToConverter x:Key="yn"/>
</Window.Resources>
<StackPanel Margin="10">
<TextBox Name="txtValue" />
<WrapPanel Margin="0,10">
<TextBlock Text="Current value is: " />
<TextBlock Name="YN" Text="{Binding ElementName=txtValue, Path=Text, Converter={StaticResource yn}}"></TextBlock>
</WrapPanel>
<CheckBox IsChecked="{Binding ElementName=txtValue, Path=Text, Converter={StaticResource yn}}" Content="{Binding ElementName=YN,Path=Text}" />
</StackPanel>
</Window>
二、多值转换IMultiValueConverter
1.首先建立一个转换类，引用using System.Windows.Data;
class YesNoToConverter2 : IMultiValueConverter
{
public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
{
//这里的values就是多个值，与前台绑定的数据有关，有几个值，就判断几个值
if (values == null || values.Length < 2)
return DependencyProperty.UnsetValue;
double verValue = (double)values[0];
double horValue = (double)values[1];
if (verValue > horValue)
return new SolidColorBrush(Colors.Green);
else if (verValue < horValue)
return new SolidColorBrush(Colors.Red);
return new SolidColorBrush(Colors.Yellow);
}
public object[] ConvertBack(object value, Type[] targetTypes, object parameter, CultureInfo culture)
{
return null;
}
}
<Window x:Class="WpfApp2.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:WpfApp2"
mc:Ignorable="d"
Title="MainWindow" Height="450" Width="800">
<Window.Resources>
<local:YesNoToConverter2 x:Key="cvtColor"/>
</Window.Resources>
<Grid>
<Label x:Name="label" Content="纵向值：" HorizontalAlignment="Left" Margin="10,40,0,0" VerticalAlignment="Top"/>
<Label x:Name="label1" Content="横向值：" HorizontalAlignment="Left" Margin="10,80,0,0" VerticalAlignment="Top"/>
<Slider x:Name="sliderVer" HorizontalAlignment="Left" Margin="75,43,0,0" VerticalAlignment="Top" Width="192"/>
<Slider x:Name="sliderHor" HorizontalAlignment="Left" Margin="75,81,0,0" VerticalAlignment="Top" Width="192"/>
<Ellipse HorizontalAlignment="Left" Height="100" Margin="75,120,0,0" Stroke="Black" VerticalAlignment="Top" Width="100">
<Ellipse.Fill>
<MultiBinding Converter="{StaticResource cvtColor}">
<Binding Path="Value" ElementName="sliderVer"/>
<Binding Path="Value" ElementName="sliderHor"/>
</MultiBinding>
</Ellipse.Fill>
</Ellipse>
</Grid>
</Window>
拓展：
多值绑定，根据Select下拉框的值来改变Name中背景颜色。
其中，Name和Select都要有属性通知，多值绑定
Select下拉框需要进行事件绑定数据
<TextBox Style="{StaticResource dgTextBox}"
Text="{Binding Name,UpdateSourceTrigger=PropertyChanged}">
<TextBox.Background>
<MultiBinding Converter="{StaticResource relayIPColorConverter}">
<Binding Path="Name" />
<Binding Path="Select" />
</MultiBinding>
</TextBox.Background>
</TextBox>
private void ComboBox_SelectionChanged_2(object sender, SelectionChangedEventArgs e)
{
var current = ((sender as ComboBox).DataContext) as StudentInfo;
switch (((ContentControl)e.AddedItems[0]).Content)
{
case "a": current.Type = 1; break;
case "b": current.Type = 2; break;
case "c": current.Type = 3; break;
}
}
来源:https://blog.csdn.net/u012563853/article/details/124874725
标签：case,object,return,绑定,value,WPF,public From： https://www.cnblogs.com/ywtssydm/p/18363298