我目前有一个组合框,其中填充了艺术家姓名,一旦选择了艺术家,我需要将其绑定到另一个组合框。在我看来,这些设置如下:
<ComboBox Height="23" HorizontalAlignment="Left" Margin="65,81,0,0" Name="comboBox1" ItemsSource="{Binding Artists}" SelectedItem="{Binding SelectedArtist}" VerticalAlignment="Top" Width="120" />
<ComboBox Height="23" HorizontalAlignment="Left" Margin="65,115,0,0" Name="comboBox2" VerticalAlignment="Top" ItemsSource="{Binding Albums}" SelectedItem="{Binding SelectedAlbums}" Width="120" />
在我的 ViewModel 中,我有以下内容:
private void initialiseArtists()
{
MusicDataClassesDataContext dataClasses = new MusicDataClassesDataContext();
artistList = (from m in dataClasses.tblArtists select m.ArtistName).ToList();
}
public List<String> Artists
{
get
{
return this.artistList;
}
}
public string SelectedArtist
{
set
{
this.selectedArtist = value;
initialiseAlbums();
}
}
private void initialiseAlbums()
{
if (selectedArtist != null)
{
MusicDataClassesDataContext dataClasses = new MusicDataClassesDataContext();
var getArtist = dataClasses.tblArtists.FirstOrDefault(band => band.ArtistName == selectedArtist);
albumList = (from album in dataClasses.tblAlbums
where album.ArtistID == getArtist.ArtistID
select album.AlbumName).ToList();
//dataClasses.tblAlbums.SelectMany(album => album.ArtistID == getArtist.ArtistID).ToList();
}
}
public List<String> Albums
{
set
{
initialiseAlbums();
}
get
{
return this.albumList;
}
}
我假设“选定的项目”事件将填充第二个组合框,但我错了。
您必须通知视图“相册”属性已更改。
这就是为什么您必须实现 INotifyPropertyChanged 接口并在构建相册列表后调用 PropertyChanged 事件。
例如
public class Musics : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
private void OnPropertyChanged(string propertyName)
{
if (PropertyChanged != null)
PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
private void initialiseAlbums()
{
if (selectedArtist != null)
{
//Your code
OnPropertyChanged("Albums");
}
}
}
使用 ObservableCollection 而不是 List 是一个很好的解决方法。
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