您正在做的事情应该可以正常工作。您需要确保在父窗口上使用SizeToContent 属性。像这样的东西:
XAML
<Window x:Class="WpfApplication1.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow"  Width="525" SizeToContent="Height">
    <Grid Height="auto" >
        <StackPanel Orientation="Vertical" >
            <TextBlock Name="tb1" TextAlignment="Justify" TextWrapping="Wrap" Text="" />
            <Grid Height="30">
                <CheckBox VerticalAlignment="Center" Name="Random">Random CheckBox</CheckBox>
            </Grid>
            <Grid Height="auto">
                <Button Name="button1" HorizontalAlignment="Right" Margin="0,0,80,0" Width="70" Height="30" Click="button1_Click" />
                <Button Name="Button2" HorizontalAlignment="Right"  Width="70" Height="30" Click="Button2_Click" />
            </Grid>
        </StackPanel>
    </Grid>
</Window>
**代码隐藏”
private void button1_Click(object sender, RoutedEventArgs e)
    {
        tb1.Text += "TextBlock with contentes set at run-time. " + 
                     "This text block should grow in height as necessary, " + 
                     "and push the other controls down.  The window itself " +
                     "should grow to \n\n Another paragraph\n";
    }