要在ItemsControl中的项之间进行通信,可以使用以下方法:
ViewModel示例代码:
public class MainViewModel : INotifyPropertyChanged
{
public event EventHandler ItemClicked;
private ObservableCollection items;
public ObservableCollection Items
{
get { return items; }
set
{
items = value;
OnPropertyChanged(nameof(Items));
}
}
// 当项被点击时触发事件
public void OnItemClicked(ItemViewModel item)
{
ItemClicked?.Invoke(this, new ItemClickedEventArgs(item));
}
// 省略其他代码...
protected virtual void OnPropertyChanged(string propertyName)
{
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
}
}
public class ItemViewModel
{
// 项的属性
}
public class ItemClickedEventArgs : EventArgs
{
public ItemViewModel ClickedItem { get; }
public ItemClickedEventArgs(ItemViewModel clickedItem)
{
ClickedItem = clickedItem;
}
}
ItemsControl的XAML代码:
事件聚合器示例代码:
public class EventAggregator
{
private static EventAggregator instance;
private Dictionary> eventHandlers;
private EventAggregator()
{
eventHandlers = new Dictionary>();
}
public static EventAggregator Instance
{
get
{
if (instance == null)
instance = new EventAggregator();
return instance;
}
}
public void Subscribe(Action handler)
{
Type eventType = typeof(TEvent);
if (!eventHandlers.ContainsKey(eventType))
eventHandlers[eventType] = new List();
eventHandlers[eventType].Add(handler);
}
public void Publish(TEvent evnt)
{
Type eventType = typeof(TEvent);
if (eventHandlers.ContainsKey(eventType))
{
foreach (var handler in eventHandlers[eventType])
{
((Action)handler)(evnt);
}
}
}
}
ViewModel示例代码:
public class MainViewModel
{
public MainViewModel()
{
EventAggregator.Instance.Subscribe(OnItemClicked);
}
private ObservableCollection items;
public ObservableCollection Items
{
get { return items; }
set
{
items = value;
OnPropertyChanged(nameof(Items));
}
}
private void OnItemClicked(ItemClickedEvent evnt)
{
// 处理项被点击事件
}
// 省略其他代码...
}
ItemsControl的XAML代码:
ItemsControl的代码-behind:
private void Button_Click(object sender, RoutedEventArgs e)
{
var button = (Button)sender;
var item = button.DataContext as ItemViewModel;
var itemClickedEvent = new ItemClickedEvent(item);
EventAggregator.Instance.Publish(itemClickedEvent);
}
请注意,以上代码示例中的ViewModel和事件聚合器的实现是简单的示例,实际的实现可能需要更多的细节和错误处理。同时,需要确保ViewModel的DataContext正确设置和绑定。