没有Path的Binding

<Window x:Class="没有Path的Binding.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:sys="clr-namespace:System;assembly=mscorlib"
        Title="MainWindow" Height="155.129" Width="209.615" Loaded="Window_Loaded">
    <Grid>
        <StackPanel>
            <StackPanel.Resources>
                <sys:String x:Key="myString">
                    菩提本无树,明镜亦非台。
                    本来无一物,何来惹尘埃。
                </sys:String>
            </StackPanel.Resources>
            <TextBlock x:Name="textBlock1" TextWrapping="Wrap"
                       Text="{Binding Path=.,Source={StaticResource ResourceKey=myString}}" FontSize="16" Margin="5" Background="Yellow"></TextBlock>
            <!--标准的写法是上面那个，下面这两个也是一样的-->
            <!--<TextBlock x:Name="textBlock1" TextWrapping="Wrap"
                       Text="{Binding .,Source={StaticResource ResourceKey=myString}}" FontSize="16" Margin="5" Background="Yellow"></TextBlock>-->
            <!--<TextBlock x:Name="textBlock1" TextWrapping="Wrap"
                       Text="{Binding Source={StaticResource ResourceKey=myString}}" FontSize="16" Margin="5" Background="Yellow"></TextBlock>-->
            <TextBlock x:Name="textBlock2" FontSize="16" Margin="5" TextWrapping="Wrap" Background="Green"></TextBlock>
        </StackPanel>
    </Grid>
</Window>

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;

namespace 没有Path的Binding
{
    /// <summary>
    /// MainWindow.xaml 的交互逻辑
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
        }

        private void Window_Loaded(object sender, RoutedEventArgs e)
        {
            string str = "菩提本无树,明镜亦非台。本来无一物,何来惹尘埃。";
            this.textBlock2.SetBinding(TextBlock.TextProperty, new Binding(".") { Source = str });
        }
    }
}