WPF绑定问题

如何解决WPF绑定问题

| 我有一个文本框，需要将字符串绑定到该文本框。

<TextBox Name=\"txtDoc\" Margin=\"5\" Text =\"{Binding Source={x:Static local:Documentviewmodel.FileText},Path=FileText}\">

FileText属性在另一个类上更改：

Documentviewmodel.GetInstance().FileText = File.ReadAllText(document.Path);

Documentviewmodel是具有Singleton的类：

public class Documentviewmodel : INotifyPropertyChanged
{
    private static string fileText;

    public string FileText
    {
        get { return fileText; }
        set
        {
            fileText = value; // Call OnPropertyChanged whenever the property is updated
            OnPropertyChanged(\"FileText\");
        }
    }

   private void OnPropertyChanged(string filetext)
    {
        PropertyChangedEventHandler handler = PropertyChanged;
        if (handler != null)
        {
            handler(this,new PropertyChangedEventArgs(filetext));
        }
    }


    public event PropertyChangedEventHandler PropertyChanged = delegate { };

    private static Documentviewmodel instance = new Documentviewmodel();

    private Documentviewmodel() { }

    public static Documentviewmodel GetInstance()
    {
        return instance;
    }
}

我需要能够更改FileText属性的值，并在文本框中反映此更改。 它不起作用。 我尝试将TextBox用作静态属性，但随后将Onp     

解决方法

        尝试将源设置为视图模型，而不是属性本身，并将and3ѭ属性设置为public？

{Binding Source={x:Static local:DocumentViewModel.instance},Path=FileText}

编辑：包括一个完整的示例，为我工作： Xaml：

<Window x:Class=\"Test.MainWindow\"
    xmlns=\"http://schemas.microsoft.com/winfx/2006/xaml/presentation\"
    xmlns:x=\"http://schemas.microsoft.com/winfx/2006/xaml\"
    xmlns:local=\"clr-namespace:Test\"
    Title=\"MainWindow\" Height=\"350\" Width=\"525\"
    Loaded=\"Window_Loaded\">
  <TextBox Name=\"txtDoc\" Margin=\"5\"
           Text=\"{Binding Source={x:Static local:DocumentViewModel.Instance},Path=FileText}\" />
</Window>

后台代码：

public partial class MainWindow : Window
{
  public MainWindow()
  {
    InitializeComponent();
  }

  private void Window_Loaded(object sender,RoutedEventArgs e)
  {
    DocumentViewModel.Instance.FileText = \"Hello world!\";      
  }
}

public class DocumentViewModel : INotifyPropertyChanged
{
  #region Singleton implementation

  // Static constructor to create the singleton instance.
  static DocumentViewModel()
  {
    DocumentViewModel.Instance = new DocumentViewModel();
  }

  public static DocumentViewModel Instance { get; private set; }

  #endregion

  private static string fileText;
  public string FileText
  {
    get { return fileText; }
    set
    {
      if (fileText != value)
      {
        fileText = value;
        OnPropertyChanged(\"FileText\");
      }
    }
  }

  #region INotifyPropertyChanged

  private void OnPropertyChanged(string filetext)
  {
    PropertyChangedEventHandler handler = PropertyChanged;
    if (handler != null)
    {
      handler(this,new PropertyChangedEventArgs(filetext));
    }
  }

  public event PropertyChangedEventHandler PropertyChanged;

  #endregion
}