[英]Call a method on all classes that implements that method
I have an Activity and 10 fragments. 我有一个Activity和10个片段。 I've created an interface and implement it on all Fragments. 我已经创建了一个接口并在所有Fragments上实现它。 How can I call that method on all Fragments from the Activity? 如何在Activity中的所有片段上调用该方法?
public interface OnConnectListener {
void isDeviceConnected(boolean b);
}
UPDATE: 更新:
Using your suggestions I did this: 使用你的建议我做了这个:
public void isDeviceConnected(boolean b, List fragmentList) {
for (OnConnectListener listener : getOnConnectListeners(fragmentList)) {
listener.isDeviceConnected(b);
}
}
public List<OnConnectListener> getOnConnectListeners(List fragmentList) {
List<OnConnectListener> listeners = new ArrayList<>();
for (Object o : fragmentList) {
if (o instanceof OnConnectListener) {
listeners.add((OnConnectListener) o);
}
}
return listeners;
}
Now I just use: 现在我只使用:
isDeviceConnected(true, fragmentList);
Thank you so much. 非常感谢。
Assuming your "Activity" class holds a reference of 10 "onConnectListener" instances, you can loop thru each and call isDeviceConnected like so: 假设您的“Activity”类包含10个“onConnectListener”实例的引用,您可以循环遍历每个实例并调用isDeviceConnected,如下所示:
private List<onConnectListener> onConnectListeners;
....
for(onConnectListener onConnectListener: onConnectListeners) {
onConnectListener.isDeviceConnected(true); // or false
}
By the way: Java naming conventions state that class names start with capital letters, and iterfaces usually start with the letter "I" So its best if you name your interface IOnConnectListener
顺便说一下:Java命名约定声明类名以大写字母开头,而且它们通常以字母“I”开头所以如果你命名你的接口IOnConnectListener
它是最好的
This is perfect case for Observer pattern 这是观察者模式的完美案例
http://www.oodesign.com/observer-pattern.html http://www.oodesign.com/observer-pattern.html
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