Question

我将我的组合框绑定到列表中，SelectedItem也绑定到代码后面的CurrentCode属性。现在每件事都显示得很好，所选项目按预期设置。但是，让我通过点击按钮更改CurrentCode的值。为什么组合框没有更新？

<ComboBox ItemsSource="{Binding Path=Codes}"
          SelectedItem="{Binding CurrentCode, 
         RelativeSource={RelativeSource FindAncestor, AncestorType=Window}, 
         Mode=OneTime}"/>


public partial class SettingsWindow
{
    public List<string> Codes { get; set; }

    public string CurrentCode
    {
        get
        {
            return Building.Code;
        }
    }

    public SettingsWindow()
    {
        InitializeComponent();

        Codes = new List<string> {"ACI Code", "BS Code"};

        DataContext = this;
    }

    private void OK_OnClick(object sender, RoutedEventArgs e)
    {
        Building.Code = "BS Code;

    }
}

Answer 1

更改属性支持字段时应该实现INotifyPropertyChanged并引发PropertyChanged事件 http://msdn.microsoft.com/en-us/library/ms743695%28v=vs.110%29.aspx

Answer 2

如果你在代码隐藏中，你可以给ComboBox一个名字并直接访问它。

如果你想让它与属性一起工作（理想情况下将它移动到它自己的类中，以MVVM方式，并将你的Window的DataContext设置为＆＃34;查看模型＆＃34;类），你＆＃ 39; ll需要实现INotifyPropertyChanged：

public partial class SettingsWindow : INotifyPropertyChanged
{
    public event PropertyChangedEventHandler PropertyChanged;

    protected virtual void OnPropertyChanged(string propertyName)
    {
        var handler = PropertyChanged;
        if (handler != null)
            handler(this, new PropertyChangedEventArgs(propertyName));
    }

    private void OK_OnClick(object sender, RoutedEventArgs e)
    {
        Building.Code = "BS Code;

        OnPropertyChanged("CurrentCode");
    }

    ...
}

组合框SelectedItem在WPF中没有更新

2 个答案: