MvvmDemo/MVVMDemo/MainWindow.xaml

<Window x:Class="MVVMDemo.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:MVVMDemo"
        mc:Ignorable="d"
        Title="MainWindow" Height="450" Width="800">
    <Window.DataContext>
        <!--// 有很多中绑定方式，这里选择了UI代码中绑定//-->
        <local:MainViewModel />
    </Window.DataContext>
    <Grid>
        <StackPanel Orientation="Vertical"
                    HorizontalAlignment="Center"
                    VerticalAlignment="Center">
            <StackPanel Orientation="Horizontal"
                        Margin="2">
                <Label Content="Origin Content: "
                       FontSize="20"
                       VerticalAlignment="Center"
                       HorizontalAlignment="Center" />
                
                <TextBox Text="{Binding TextContent, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"
                         TextWrapping="Wrap"
                         MinWidth="400"
                         MaxWidth="600"
                         FontSize="20"
                         Padding="4"/>
            </StackPanel>
            
            <StackPanel Orientation="Horizontal"
                        Margin="2">
                <Label Content="Sync Content:    "
                       FontSize="20"
                       VerticalAlignment="Center"
                       HorizontalAlignment="Center" />

                <TextBlock Text="{Binding TextContent}"
                           TextWrapping="Wrap"
                           MinWidth="400"
                           MaxWidth="600"
                           FontSize="20"
                           Padding="4"/>
            </StackPanel>

            <!--// CommandParameter: 绑定对象到BtnCmd上 //-->
            <Button Content="Reset"
                    Command="{Binding BtnCmd}"
                    CommandParameter="{Binding RelativeSource={RelativeSource AncestorType=Window}}"
                    FontSize="30" />
        </StackPanel>
    </Grid>
</Window>