如何使用MVVM和MVVM工具包将属性绑定到文本框？

Question

我是MVVM的新手.学习我创建了一个示例应用程序,以便在单击按钮时在文本框中显示消息.在我的代码中,button命令工作正常,但属性未绑定到Textbox.如何使用MVVM将Property绑定到Textbox？

我的代码类似于下面给出的.

视图

<TextBox Name="MessageTextBox" Text="{Binding TestMessage}"/>
<Button Content="Show" Name="button1" Command="{Binding ShowCommand}">
 <!-- Command Handler -->
</Button>

查看模型

MyMessage myMessage; 
public MainViewModel()
{
myMessage=new MyMessage();
}

//inside the ShowCommand Handler

TestMessage="Hello World";

// A Property to set TextBox Value. 

模型

public class MyMessage: INotifyPropertyChanged        
{     
    private string testMessage;
    public string TestMessage
    {
        get { return testMessage; }
        set
        { 
            testMessage= value;
            OnPropertyChanged("TestName");
        }
    }
    public event PropertyChangedEventHandler PropertyChanged;
    private void OnPropertyChanged(string propertyName)
    {
        if (PropertyChanged != null)
        {
            PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
        }
    }

}

Answer 1

• 在你的模型中你有textMessage作为int而不是字符串？

尝试这样的事情:

视图模型

 private MyMessage message;

 public MainViewModel()
 {
    message = new MyMessage();
 }

public MyMessage Message
{
    get { return message;}
    set { message = value;}
}

//in your command: 
this.Message.TestMessage = "Hello World!";

模型

public class MyMessage: INotifyPropertyChanged
{
   private string testMessage

   public string TestMessage;
   { 
      get{ return testMessage; }
      set
         { 
           testMessage = value; 
           this.OnPropertyChanged("TestMessage");
         } 
   }
     //INotifyChanged Events   
}

XAML

<TextBox Text="{Binding Message.TestMessage, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"/>

Answer 2

我不明白你的代码,但我想你应该修复你的绑定:

<TextBox Name="MessageTextBox" Text="{Binding MyMessage.TestMessage}"/>

哪里MyMessage应该是公共财产MainViewModel