关于数据绑定到CLR中的问题

Question

在做一个数据绑定到CLR中的工程时，发现CLR中的数据无法绑定到element上，代码具体如下

 

 public partial class MainWindow : Window
 {
 Person person;
 Name name;
 Address addr;
 public MainWindow()
 {
 InitializeComponent();
 name =new Name(
 "Jack",
 "Wang"
 );
 addr = new Address(
 "Work",
 "Redmond",
 "One Microsoft Way",
 "WA",
 "950853"
 );
 person = new Person(name, addr);
 DataContext = person;
 
 }

Person.cs

 public class Person
 {
 Name name;
 Address address;
 public Person(Name nam, Address addr)
 {
 name = nam;
 address = addr;
 }
 }

Name.cs

 public class Name:INotifyPropertyChanged
 {
 private string first;
 private string First
 {
 get { return first; }
 set { 
 first = value;
 NotifyChanged("First");
 }
 }

 public string second;
 public string Second
 {
 get { return second; }
 set { second = value; }
 }

 public Name(string first, string second)
 {
 First = first;
 Second = second;
 }

 public event PropertyChangedEventHandler PropertyChanged;
 void NotifyChanged(string property)
 { 
 if(PropertyChanged!=null)
 PropertyChanged(this,new PropertyChangedEventArgs(property));
 }

 }

Addresses.cs

public class Address
 {
 public string addressName;
 public string AddressName
 {
 get { return addressName; }
 set { addressName = value; }
 }

 public string city;
 public string City
 {
 get { return city; }
 set { city = value; }
 }

 public string state;
 public string State
 {
 get { return state; }
 set { state = value; }
 }

 public string street;
 public string Street
 {
 get { return street; }
 set { street = value; }
 }

 public string zip;
 public string Zip
 {
 get { return zip; }
 set { zip = value; }
 }

 public Address(string addname, string city, string state, string street, string zip)
 {
 AddressName = addname;
 City = city;
 State = state;
 Street = street;
 Zip = zip;
 }

MainWindow.XAML

<Window x:Class="WpfDateBinding.MainWindow"
  xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
  xmlns:l="clr-namespace:WpfDateBinding"
  Title="MainWindow" Height="350" Width="525">
 <StackPanel>
 <TextBlock Height="23" Name="TextBlock1" Text="{Binding Path=Name.First, Mode=OneWay}" />
 <TextBlock Height="23" Name="TextBlock2" Text="{Binding Path=Name.Second,Mode=OneWay}" />
 </StackPanel>
</Window>

 

Answer 1

程序运行时 两个text都是空值，调试时，发现DataContext已经成功赋值。我一种猜测是这个DataContext指向并不明确。

Answer 2

WPF中的绑定支持的是 CLR 属性，也就是有Set和Get访问器。但是你的Person类中，Name不是属性，所以绑定无效。

除了这个你还有几个错误，一是要注意大小写；二是要注意被绑定的属性必须是Public的，在C#中不写访问修饰符，默认是internal。

下面是正确的代码：

  <StackPanel>
    <TextBlock Height="23" Name="TextBlock1" Text="{Binding Path=name.First, Mode=OneWay}" />
    <TextBlock Height="23" Name="TextBlock2" Text="{Binding Path=name.Second,Mode=OneWay}" />
    <!-- 注意name的大小写 -->
  </StackPanel>

 

C#：

  public class Person
  {
    public Name name { get; set; }
    public Address address { get; set; }
    // 注意需要是属性，而且加上public
    public Person(Name nam, Address addr)
    {
      name = nam;
      address = addr;
    }
  }

 

  public class Name : INotifyPropertyChanged
  {
    private string first;
    public string First
    {
      get { return first; }
      set
      {
        first = value;
        NotifyChanged("First");
      }
    }
 
    private string second;
    public string Second
    {
      get { return second; }
      set { second = value; }
    }
    //注意访问修饰符
    ......

 

 

Sincerely,

 

 

---

Bob Bao [MSFT]
MSDN Community Support | Feedback to us
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Answer 3

Thanks,Bob