Android回调事件传播-android学习之旅（四十五）

概念简介

代码演示

package peng.liu.test;

import android.app.ActionBar;
import android.app.Activity;
import android.graphics.Color;
import android.os.Bundle;
import android.util.DisplayMetrics;
import android.view.Display;
import android.view.KeyEvent;
import android.view.Menu;
import android.view.View;
import android.view.Window;
import android.view.WindowManager;
import android.widget.Button;


public class MainActivity extends Activity{
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        findViewById(R.id.myButton).setOnKeyListener(new View.OnKeyListener() {
            @Override
            public boolean onKey(View view, int i, KeyEvent keyEvent) {
                System.out.println("listener on listener");
                return false;
            }
        });
    }
    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        super.onKeyDown(keyCode, event);
        System.out.println("listener on activity");
        return false;
    }
}

package peng.liu.test;

import android.content.Context;
import android.content.SyncStatusObserver;
import android.util.AttributeSet;
import android.view.KeyEvent;
import android.widget.Button;

/**
 * Created by lplp on 2015/6/10.
 */
public class MyButton extends Button{
    public MyButton(Context context,AttributeSet attributeSet){
        super(context,attributeSet);
    }

    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        super.onKeyDown(keyCode, event);
        System.out.println("listener on Button");
        return false;
    }
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    >
    <peng.liu.test.MyButton
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:id="@+id/myButton"
        />
</LinearLayout>

打印顺序

listener on listener
listener on Button
listener on activit
说明先到绑定的监听器，后到Button复写回调的监听器，最后到acticity实现的监听器。