当注入对象的属性发生更改时调用类中的方法
本文关键字:调用 方法 对象 注入 属性 | 更新日期: 2023-09-27 17:56:03
如果我有一个成员,构造函数和这样的方法
//The injected object exposes a public property of type bool which will raise
//a NotifyPropertyChangedEvent
IInjectedObject _injectedObject;
public someClass(IInjectedObject injectedObject)
{
_injectedObject = injectedObject;
}
public void DoSomething()
{
}
当注入对象的属性更改时,有没有办法在我的类中调用该方法?
您声明您的接口继承自 INotifyPropertyChanged,因此可以合理地预期它会通过"PropertyChanged"事件通知侦听器属性更改。 假设像这样:
public interface IInjectedObject : INotifyPropertyChanged
{
bool MyImportantProperty { get; }
}
然后,依赖对象必须侦听 INotifyPropertyChanged.PropertyChanged
事件:
public class MyDependantClass
{
public MyDependantClass(IInjectedObject injectedObject)
{
MyInjectedObject = injectedObject;
}
// We wrap the private field in a protected property,
// to capture the event subscriptions
private IInjectedObject _myInjectedObject;
protected IInjectedObject MyInjectedObject
{
get { return _myInjectedObject; }
set
{
// unsubscribe from the old property's event
if(_myInjectedObject!= null)
_myInjectedObject.PropertyChanged -= OnPropertyChanged;
_myInjectedObject= value;
// subscribe to the new property's event
if(_myInjectedObject!= null)
_myInjectedObject.PropertyChanged += OnPropertyChanged;
}
}
private void OnPropertyChanged(object sender, PropertyChangedEventArgs args)
{
if(args.PropertyName == "MyImportantProperty")
{
//react to the changed property here!
}
}
}