c# - 正确更新 MVVM 中的 ComboBox 选定项

Question

给定以下 ViewModel 代码 - cmbxFields 绑定(bind)到 ComboBox ItemSource，SelectedcmbxField 绑定(bind)到所选项目 - ComboBox 所选项目在我导航之前不会更新离开并返回 View (Page)。在 MVVM 中执行此操作以使 ComboBox 立即更新的正确方法是什么？

public ObservableCollection<string> cmbxFields { get; set; } = new ObservableCollection<string>();
public string SelectedCmbxField { get; set; }

private async Task LoadWorkspaceFields()
{
    cmbxFields.Clear();
    foreach (var curField in availableFields.OrderBy(x =>x.Name).Select(x => x.Name))
    {
        cmbxFields.Add(curField);
    }

    SelectedCmbxField = cmbxFields.FirstOrDefault(x => x.StartsWith("Some Text"));
}

我已经在我的 ComboBox XAML 上尝试了以下内容-

SelectedItem="{Binding SelectedcmbxField, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"

Answer 1

INotifyPropertyChanged 实现的简单示例:

public class MyClass : INotifyPropertyChanged
{
  private int intValue;

  public event PropertyChangedEventHandler PropertyChanged;

  public int MyIntValue
  {
    get => intValue;
    set
    {
      intValue = value;
       PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(MyIntValue)));
    }
  }
}