Question

我很难让我的WPF正确使用数据绑定。在XAML中，我有以下内容：

....
<TextBox Name="txt_FirstName" Text="{Binding Path=currentApplication.FirstName, UpdateSourceTrigger=PropertyChanged}" />
....

我有以下CS代码：

namespace WPF1
{
  public partial class MainWindow : Window
  {
    personalApp currentApplication = new personalApp ();

    public MainWindow()
    {
      InitializeComponent();
    }

  }
}

引用以下两个类：

class personalApp : INotifyPropertyChanged
{
  private Person person = new Person();

  public string FirstName
  {
    get { return person.FirstName; }
    set
    {
      person.FirstName = value;
      this.OnPropertyChanged("FirstName");
    }
  }

  public event PropertyChangedEventHandler PropertyChanged;

  void OnPropertyChanged(string propName)
  {
    if (this.PropertyChanged != null)
      this.PropertyChanged(
      this, new PropertyChangedEventArgs(propName));
   }

}

class Person
{
  private string firstName = "";

  get { return firstName; }
  set { FirstName = value; }
}

我在代码中暂停它并逐步检查，但是当我更新应用程序中的txt_FirstName时，它似乎永远不会设置firstName对象。

我哪里错了？

Answer 1

您需要更新XAML绑定，并使用DataContext设置窗口的TextBox。

namespace WPF1
{
  public partial class MainWindow : Window
  {
    personalApp currentApplication = new personalApp ();

    public MainWindow()
    {
      InitializeComponent();
      this.DataContext = currentApplication;
    }
  }
}

更新XAML：

<TextBox Name="txt_FirstName" Text="{Binding FirstName, UpdateSourceTrigger=PropertyChanged}" />

Answer 2

我已经更正了代码。

对于文本框：

<TextBox Name="txt_FirstName" Height="30" Background="Beige"
             Text="{Binding Path=FirstName, UpdateSourceTrigger=PropertyChanged}" />

C＃代码

namespace Wpf1
{
/// <summary>
/// Interaction logic for MainWindow.xaml
/// </summary>
public partial class MainWindow : Window
{
    public MainWindow()
    {
        InitializeComponent();
        this.DataContext = new personalApp();
    }
}

internal class personalApp : INotifyPropertyChanged
{
    private Person person = new Person();

    public string FirstName
    {
        get { return person.FirstName; }
        set
        {
            person.FirstName = value;
            this.OnPropertyChanged("FirstName");
        }
    }

    public event PropertyChangedEventHandler PropertyChanged;

    private void OnPropertyChanged(string propName)
    {
        if (this.PropertyChanged != null)
            this.PropertyChanged(
            this, new PropertyChangedEventArgs(propName));
    }
}

internal class Person
{
    public string FirstName { get; set; }
}
}

Answer 3

public MainWindow()
{
  DataContext = this;
  InitializeComponent();
}

或者如果您不想为自己（窗口）分配数据上下文，因为您可能有其他datacontext进入窗口，您可以在xaml中添加：给你的窗口一个名字：

<Window .... x:Name="this"...

然后

<TextBox Name="txt_FirstName" Text="{Binding ElementName=this,
                                     Path=currentApplication.FirstName/>

Answer 4

“更新应用程序中的txt_FirstName”是什么意思？如果直接设置文本框的值，则应尝试设置currentApplication的值而不是文本框值

DataBinding到TextBox无法正常工作

4 个答案: