WPF,数据绑定,为什么不能设置Source属性
<TextBox Name="tex1" Text="{Binding Path=Name}" HorizontalAlignment="Left" Height="23" Margin="92,168,0,0" TextWrapping="Wrap" VerticalAlignment="Top" Width="120"/>
Binding binding = BindingOperations.GetBinding(tex1, TextBox.TextProperty);
binding.Source = list;