<Window x:Class="WPF_15_MvvmLightMessage.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"
        mc:Ignorable="d"
        Title="MainWindow" Height="450" Width="800">
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto" />
            <RowDefinition />
        </Grid.RowDefinitions>

        <StackPanel Grid.Row="0">
            <TextBox Name="InputTextBox" Height="40" />
            <Button Height="40" Command="{Binding SendMessageCommand}"
                    CommandParameter="{Binding ElementName=InputTextBox,Path=Text}">
                发送消息
            </Button>
        </StackPanel>
    </Grid>
</Window>