google推荐方法添加static,但我的目前并不喜欢那样子java
目前对几种handler写法进行了测试,测试方法与结果以下:android
package com.android.chaos; import android.app.Activity; import android.content.Intent; import android.os.Bundle; import android.view.View; import android.widget.Button; import com.example.myreveallayout.R; public class MainActivity extends Activity{ private Button button; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); button = (Button) findViewById(R.id.button); button.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { Intent intent = new Intent(); intent.setClass(MainActivity.this,TestActivity.class); startActivity(intent); } }); } }
package com.android.chaos; import android.app.Activity; import android.os.Bundle; import android.os.Handler; import android.os.Message; import com.example.myreveallayout.R; import java.lang.ref.WeakReference; /** * 项目名称: * 类描述: * 建立人: * 建立时间:2016/6/15 15:02 * 修改人: * 修改时间:2016/6/15 15:02 * 修改备注: */ public class TestActivity extends Activity { //2,3写法虽然不会被lint检查出来,但任然会形成leak,第四,五种测试目前不会形成内存没法回收 //第5种写法,会让调用方法都要写成static,对应的一些成员变量也要变成static //测试方法:不停点击mainActivity中button,在studion 中查看内存状况 //建议在onDestory中添加handler.removeCallbacksAndMessages(null);移除 @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); //第四种方案 MyHandler handler = new MyHandler(this); handler.sendEmptyMessageDelayed(111,60 * 10 * 1000); finish(); } //第一种方案 /*private static Handler handler = new Handler(){ @Override public void handleMessage(Message msg) { super.handleMessage(msg); } };*/ //第二种方案 private Handler handler = new Handler(new Handler.Callback() { @Override public boolean handleMessage(Message msg) { return false; } }) ; //第三种方案 public class TestActivity extends Activity implements Handler.Callback //实例化时 Handler handler = new Handler(this) //第五种方案 /*private static Handler handler = new Handler(new Handler.Callback() { @Override public boolean handleMessage(Message msg) { return false; } }) ;*/ private static class MyHandler extends Handler { WeakReference<Activity > mActivityReference; MyHandler(Activity activity) { mActivityReference= new WeakReference<Activity>(activity); } @Override public void handleMessage(Message msg) { final TestActivity activity = (TestActivity) mActivityReference.get(); if (activity != null && !activity.isFinishing()) { activity.set(); } } } private void set(){ // TODO: 2016/6/15 } }