WPF数据绑定到数据对象中的字典

Question

我有一个 USER 数据对象，其中包含这样的字典：

public class User : INotifyPropertyChanged
{
   private Dictionary<string, object> _metadata;

   public Dictionary<string, object> Metadata
    {
        get { return this._metadata; }
        set
        {
            this._metadata = value;                
            OnPropertyChanged("Metadata", value);
        }
    }
    protected void OnPropertyChanged(string property, object value)
    {           
        if (PropertyChanged != null)
        {
            PropertyChanged(this, new PropertyChangedEventArgs(property));
        }
    }
}

我也有 ViewModel 由这样的用户数据对象组成：

public class ViewModel : INotifyPropertyChanged
{  
public static ViewModel getInstance()
        {
            if (instance == null)
                instance = new ViewModel();
            return instance;
        }
private User _user;

public User User
        {
            get { return this._user; }
            set
            {
                this._user = value;
                OnPropertyChanged("User", value);
            }
        }
protected void OnPropertyChanged(string property, object value)
        {
            if (PropertyChanged != null)
            {
                PropertyChanged(this, new PropertyChangedEventArgs(property));
            }
        }
}  

然后在我的主窗口中，我在文本框和字典值（不是字典键 ....）之间进行数据绑定。

Binding myBinding = new Binding();
myBinding.Source = ViewModel.getInstance().User.Metadata;
myBinding.Path = new PropertyPath("SomeDictonaryKey");
myBinding.Mode = BindingMode.TwoWay;
myBinding.UpdateSourceTrigger = UpdateSourceTrigger.PropertyChanged;
BindingOperations.SetBinding(tb1, TextBox.TextProperty, myBinding));

但它不起作用，我尝试了不同的方法来更改 binding.path 和 binding.source，它仍然不起作用....

谁能告诉我这是什么问题？？？

Answer 1

您可以通过标准索引器语法绑定到字典值：

Binding myBinding = new Binding();
myBinding.Source = ViewModel.getInstance().User;
myBinding.Path = new PropertyPath("Metadata[SomeDictonaryKey]");
myBinding.Mode = BindingMode.TwoWay;
myBinding.UpdateSourceTrigger = UpdateSourceTrigger.PropertyChanged;
BindingOperations.SetBinding(tb1, TextBox.TextProperty, myBinding));

或者您可以使用 source 指定绑定源的所有路径：

myBinding.Source = ViewModel.getInstance().User.Metadata[SomeDictonaryKey];
myBinding.Path = new PropertyPath(".");

您可以找到更多示例here。