Android：回调机制
public class Fruits {
public interface Apple {
public String info();
}
}
//匿名内部类
public class Test {
public static void main(String[] args) {
// TODO Auto-generated method stub
Fruits.Apple apple = new Fruits.Apple() {
@Override
public String info() {
// TODO Auto-generated method stub
return "I am an Apple";
}
};
System.out.println(apple.info());// I am an Apple
}
}
//继承接口
public class SonFruits implements Fruits.Apple {
public static void main(String[] args) {
// TODO Auto-generated method stub
SonFruits sonFruits = new SonFruits();
sonFruits.info();
System.out.println("sonFruits.info()->" + sonFruits.info());
}
@Override
public String info() {
// TODO Auto-generated method stub
return "I am an Apple!";
}
}
//回调方法的接口
public interface CallBack {
public void callBackMethod();
}
//回调方法的实现类
public class CallBackListener implements CallBack {
@Override
public void callBackMethod() {
// TODO Auto-generated method stub
System.out.println("回调");
}
}
//调用类
public class Caller {
private CallBackListener callBackListener;
public void call() {
this.callBackListener.callBackMethod();
}
public void setCalBack(CallBackListener callBackListener2) {
this.callBackListener = callBackListener;
}
}
//业务处理类
public class Main {
public static void main(String[] args) {
// TODO Auto-generated method stub
Caller caller = new Caller();
caller.setCalBack(new CallBackListener());
caller.call();
}
}
Button点击事件
CallBack------->OnClickListener接口
CallBackListener--------->实现OnClickListener接口的类
Caller-------->Button对象
Main-------->业务处理类（Activity）
举个栗子
frameworks/base/core/java/android/view/GestureDetector.java
public class GestureDetector {
1.
public interface OnGestureListener {//内部 手势接口
2.
public static class SimpleOnGestureListener implements OnGestureListener, OnDoubleTapListener {//实现接口的类
will@s2:~/ZK-Rxxx_Android7.1/ZK_RXXX_RK3288_ANDROID7.1$ grep -rn "SimpleOnGestureListener" ./frameworks/base/services/
./frameworks/base/services/core/java/com/android/server/policy/SystemGesturesPointerEventListener.java:267: private final class FlingGestureDetector extends GestureDetector.SimpleOnGestureListener {
./frameworks/base/services/core/java/com/android/server/display/OverlayDisplayWindow.java:363: new GestureDetector.SimpleOnGestureListener() {
./frameworks/base/services/core/java/com/android/server/wm/TaskTapPointerEventListener.java:181: private final class TwoFingerScrollListener extends GestureDetector.SimpleOnGestureListener {
./frameworks/base/services/accessibility/java/com/android/server/accessibility/AccessibilityGestureDetector.java:43:class AccessibilityGestureDetector extends GestureDetector.SimpleOnGestureListener {
./frameworks/base/services/accessibility/java/com/android/server/accessibility/MagnificationGestureHandler.java:26:import android.view.GestureDetector.SimpleOnGestureListener;
./frameworks/base/services/accessibility/java/com/android/server/accessibility/MagnificationGestureHandler.java:332: private final class MagnifiedContentInteractionStateHandler extends SimpleOnGestureListener
will@s2:~/ZK-Rxxx_Android7.1/ZK_RXXX_RK3288_ANDROID7.1$
3.
/frameworks/base/services/core/java/com/android/server/policy/SystemGesturesPointerEventListener.java
private final class FlingGestureDetector extends GestureDetector.SimpleOnGestureListener {
4.
frameworks/base/services/core/java/com/android/server/policy/PhoneWindowManager.java
// monitor for system gestures
mSystemGestures = new SystemGesturesPointerEventListener(context,
new SystemGesturesPointerEventListener.Callbacks() { //业务处理
