不久前遇到一个问题，在绑定的时候打算将数据模型类全部设置为internal类型，进行模块的封装。不过当设置为internal之后绑定居然不起作用了。代码如下：
数据模型部分：

public abstract class NotifyBind : INotifyPropertyChanged{public event PropertyChangedEventHandler PropertyChanged;public void OnPropertyChanged(string propname){if (this.PropertyChanged != null){PropertyChanged(this, new PropertyChangedEventArgs(propname));}}}public class MainModel:NotifyBind{private string ishowTest = string.Empty;private string pshowTest = string.Empty;internal string IShowTest{get { return this.ishowTest; }set{this.ishowTest = value;this.OnPropertyChanged("IShowTest");}}public string PShowTest{get { return this.pshowTest; }set{this.pshowTest = value;this.OnPropertyChanged("PShowTest");}}}

页面部分：

<Window x:Class="TestInternalBinding.MainWindow"xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"Title="MainWindow" Height="436" Width="803"><Grid><TextBox Height="30" HorizontalAlignment="Left" Margin="130,120,0,0" Name="textBox1" VerticalAlignment="Top" Width="186"Text="{Binding PShowTest,Mode=TwoWay,UpdateSourceTrigger=PropertyChanged}"/><TextBox Height="30" HorizontalAlignment="Left" Margin="130,170,0,0" Name="textBox2" VerticalAlignment="Top" Width="186"Text="{Binding IShowTest,Mode=TwoWay,UpdateSourceTrigger=PropertyChanged}"/><Button Content="public绑定" Height="23" HorizontalAlignment="Left" Margin="333,127,0,0" Name="button1" VerticalAlignment="Top" Width="85" Click="button1_Click" /><Button Content="internal绑定" Height="23" HorizontalAlignment="Left" Margin="333,174,0,0" Name="button2" VerticalAlignment="Top" Width="85" Click="button2_Click" /></Grid>
</Window>

后台部分：

 public partial class MainWindow : Window{private MainModel data = new MainModel();public MainWindow(){InitializeComponent();this.DataContext = data;}private void button1_Click(object sender, RoutedEventArgs e){string showstring = string.IsNullOrEmpty(data.PShowTest) ? "空" : data.PShowTest;MessageBox.Show("当前为public绑定，输入内容为：" + showstring);}private void button2_Click(object sender, RoutedEventArgs e){string showstring = string.IsNullOrEmpty(data.IShowTest) ? "空" : data.IShowTest;MessageBox.Show("当前为internal绑定，输入内容为：" + showstring);}}

当输入文字到文本框后，分别触发按钮点击时间后，如下图：
1、字段为public的，

2、字段为internal的，

可以看出字段为internal后，绑定是没有作用的。所以在绑定的时候数据模型类，必须为public类型才可以。

代码下载： http://download.csdn.net/detail/yysyangyangyangshan/5238192