Android回調事件傳播-android學習之旅（四十五）

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概念簡單介紹

代碼示範

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>

列印順序

listener on listener
listener on Button
listener on activit
說明先到綁定的監聽器，後到Button複寫回調的監聽器。最後到acticity實現的監聽器。

Android回調事件傳播-android學習之旅（四十五）