<Window
    x:Class="checkboxtest.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:local="clr-namespace:checkboxtest"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    Title="MainWindow"
    Width="800"
    Height="450"
    mc:Ignorable="d">
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto" />
        </Grid.RowDefinitions>
        <StackPanel Orientation="Vertical">
            <CheckBox Name="checkbox" Content="java" IsChecked="{Binding ChkChecked}" />
            <Button Click="Button_Click" Content="click" />
        </StackPanel>
    </Grid>
</Window>
using System.Windows;
namespace checkboxtest
    /// <summary>
    /// MainWindow.xaml 的交互逻辑
    /// </summary>
    public partial class MainWindow : Window
        public MainWindow()
            InitializeComponent();
        public bool? ChkChecked { get; set; }
        private void Button_Click(object sender, RoutedEventArgs e)
            ChkChecked = !ChkChecked;
 
https://oomake.com/question/2211787
 
using System.ComponentModel;
using System.Windows;
namespace checkboxtest
    /// <summary>
    /// MainWindow.xaml 的交互逻辑
    /// </summary>
    public partial class MainWindow : Window, INotifyPropertyChanged
        public MainWindow()
            InitializeComponent();
            this.DataContext = this;
        private bool? chkChecked = false;
        public bool? ChkChecked
                return chkChecked;
                chkChecked = value;
                RaisePropertyChanged("ChkChecked");
        public event PropertyChangedEventHandler PropertyChanged;
        private void RaisePropertyChanged(string _Prop)
            if (PropertyChanged != null)
                this.PropertyChanged(this, new PropertyChangedEventArgs(_Prop));
        private void Button_Click(object sender, RoutedEventArgs e)
            ChkChecked = !ChkChecked;
同时有字段和属性
 
必须同时有字段和属性, 否则启动报错
 
 
空指针错误
 
有时候会报如下空指针错误
 
 代码修改为如下即可
 
        #region INotifyPropertyChanged
        public event PropertyChangedEventHandler PropertyChanged;
        private void RaisePropertyChanged(string prop)
            if (null != prop && IsLoaded)
                PropertyChanged(this, new PropertyChangedEventArgs(prop));
        #endregion INotifyPropertyChanged
                    错误版xaml&lt;Window    x:Class="checkboxtest.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"  
        <CheckBox x:Name="cb1" Grid.Row="1" Margin="5,0,0,0" 
            Content="Three-state CheckBox" IsThreeState="True"
            Checked="HandleCheck" Unchecked="HandleUnchecked" 
            Indeterminate="HandleThirdState" Background="Red" 
				
1.CheckBox控件介绍
复选框    允许可以选择多个     ContentControl
常用属性  Content   Name  IsChecked(true false null)  IsThreeState  Tag
获取已勾选选项   父容器  —Grid  Children —子元素的集合
2.具体案例
<Grid Name="grid1">
    <!--中间状态时 IsChecked  空-->
    <!--<CheckBox .
&lt;Style x:Key="CheckBoxStyle" TargetType="{x:Type CheckBox}"&gt;
        &lt;Setter Property="SnapsToDevicePixels" Value="true" /&gt;
        &lt;Setter Property="OverridesDefaultStyl
<Window x:Class="Treeview.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
现象：当一个对象集合里，某些属性需要以RadioButton或者CheckBox的形式展现出来，并且会随着切换集合中的对象而变化时，RadioButton绑定不会正确更新，而CheckBox则没问题；
这里以一个小例子来说明：
一个学生集合，每个学生其中包含一个性别属性S
如果控件有选择事件的话这一在XAML中直接IsChecked=true可能出问题
因为程序编译先执行初始化控件后执行窗体load等事件，所以在XAML中直接IsChecked=true便会在控件加载中便执行选择事件，再执行窗体事件和全局变量，很可能会报错，这时不要在XAML中直接IsChecked=true，而要在窗体load事件中手动写一下代码
<StackPanel>
    <CheckBox x:Name="cbAll" Content="全选" Checked="cbAll_Checked" Unchecked="cbAll_Unchecked"/>
    <CheckBox Content="选项1" IsChecked="{Binding IsChecked, ElementName=cbAll, Mode=OneWay}"/>
    <CheckBox Content="选项2" IsChecked="{Binding IsChecked, ElementName=cbAll, Mode=OneWay}"/>
    <CheckBox Content="选项3" IsChecked="{Binding IsChecked, ElementName=cbAll, Mode=OneWay}"/>
</StackPanel>
C# 代码：
private void cbAll_Checked(object sender, RoutedEventArgs e)
    foreach (var item in (sender as CheckBox).Parent.Children)
        if (item is CheckBox && item != sender)
            (item as CheckBox).IsChecked = true;
private void cbAll_Unchecked(object sender, RoutedEventArgs e)
    foreach (var item in (sender as CheckBox).Parent.Children)
        if (item is CheckBox && item != sender)
            (item as CheckBox).IsChecked = false;
希望能够帮到您！
                    flyingju: 
https://mirror.bit.edu.cn/apache/skywalking/8.3.0/apache-skywalking-apm-es7-8.3.0.tar.gz
                .net NLog
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