一、概述
前面一篇文章Android通过AIDL实现跨进程更新UI我们学习了aidl跨进程更新ui，这种传统方式实现跨进程更新UI是可行的，但有以下弊端：
View中的方法数比较多，在IPC中需要增加对应的方法比较繁琐。 View的每一个方法都会涉及到IPC操作，多次IPC带来的开销问题不容小觑。 View中方法的某些参数可能不支持IPC传输。例如：OnClickListener，它仅仅是个接口没有序列化。
接下来我们通过RemoteViews实现跨进程更新UI
二、实现效果图
在同一个应用中有两个Activity，MainActivity和Temp2Activity，这两个Activity不在同一个进程中。
现在需要通过Temp2Activity来改变MainActivity中的视图，即在MainActivity中添加两个Button，也就是实现跨进程更新UI这么一个功能。
在MainActivity里点击“跳转到新进程ACTIVITY”按钮，会启动一个新进程的Temp2Activity，我们先点击“绑定服务”，这样我们就启动了服务，再点击“AIDL更新”按钮，通过调用handler来实现跨进程更新UI，点击返回，我们发现MainActivity页面中新添加了两个按钮，并且按钮还具有点击事件。
三、核心代码
IremoteViewsManager.aidl
里面提供了两个方法，一个是根据id更新TextView里面的内容，一个是根据id添加view视图
// IremoteViewsManager.aidl.aidlpackage com.czhappy.remoteviewdemo;interface IremoteViewsManager { void addRemoteView(in RemoteViews remoteViews);}
RemoteViewsAIDLService.Java
package com.czhappy.remoteviewdemo.service;import android.app.Service;import android.content.Intent;import android.os.Binder;import android.os.Bundle;import android.os.IBinder;import android.os.Message;import android.os.RemoteException;import android.widget.RemoteViews;import com.czhappy.remoteviewdemo.IremoteViewsManager;import com.czhappy.remoteviewdemo.activity.MainActivity;/** * Description: * User: chenzheng * Date: 2017/2/10 0010 * Time: 10:56 */public class RemoteViewsAIDLService extends Service { private static final String TAG = "RemoteViewsAIDLService"; private Binder remoteViewsBinder = new IremoteViewsManager.Stub(){ @Override public void addRemoteView(RemoteViews remoteViews) throws RemoteException { Message message = new Message(); message.what = 1; Bundle bundle = new Bundle(); bundle.putParcelable("remoteViews",remoteViews); message.setData(bundle); new MainActivity.MyHandler(RemoteViewsAIDLService.this,getMainLooper()).sendMessage(message); } }; public RemoteViewsAIDLService() { } @Override public IBinder onBind(Intent intent) { return remoteViewsBinder; }}
MainActivity.java
package com.czhappy.remoteviewdemo.activity;import android.content.Context;import android.content.Intent;import android.os.Bundle;import android.os.Handler;import android.os.Looper;import android.os.Message;import android.support.v7.app.AppCompatActivity;import android.util.Log;import android.view.LayoutInflater;import android.view.View;import android.widget.LinearLayout;import android.widget.RemoteViews;import android.widget.TextView;import com.czhappy.remoteviewdemo.R;import java.lang.ref.WeakReference;public class MainActivity extends AppCompatActivity { private static String TAG = "MainActivity"; private static LinearLayout mLinearLayout; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); mLinearLayout = (LinearLayout) this.findViewById(R.id.mylayout); } public static class MyHandler extends Handler { WeakReference<Context> weakReference; public MyHandler(Context context, Looper looper) { super(looper); weakReference = new WeakReference<>(context); } @Override public void handleMessage(Message msg) { super.handleMessage(msg); Log.i(TAG, "handleMessage"); switch (msg.what) { case 1: //RemoteViews的AIDL实现 RemoteViews remoteViews = msg.getData().getParcelable("remoteViews"); if (remoteViews != null) { Log.i(TAG, "updateUI"); View view = remoteViews.apply(weakReference.get(), mLinearLayout); mLinearLayout.addView(view); } break; default: break; } } }; public void readyGo(View view){ Intent intent = new Intent(MainActivity.this, Temp2Activity.class); startActivity(intent); }}
Temp2Activity.java
package com.czhappy.remoteviewdemo.activity;import android.app.PendingIntent;import android.content.ComponentName;import android.content.Context;import android.content.Intent;import android.content.ServiceConnection;import android.os.Bundle;import android.os.IBinder;import android.os.RemoteException;import android.support.annotation.Nullable;import android.support.v7.app.AppCompatActivity;import android.util.Log;import android.view.View;import android.widget.RemoteViews;import com.czhappy.remoteviewdemo.IremoteViewsManager;import com.czhappy.remoteviewdemo.R;import com.czhappy.remoteviewdemo.service.RemoteViewsAIDLService;/** * Description: * User: chenzheng * Date: 2017/2/9 0009 * Time: 16:05 */public class Temp2Activity extends AppCompatActivity { private String TAG = "Temp2Activity"; private IremoteViewsManager remoteViewsManager; private boolean isBind = false; private ServiceConnection remoteViewServiceConnection = new ServiceConnection() { @Override public void onServiceConnected(ComponentName name, IBinder service) { Log.i(TAG,"onServiceConnected"); remoteViewsManager = IremoteViewsManager.Stub.asInterface(service); } @Override public void onServiceDisconnected(ComponentName name) { //回收 remoteViewsManager = null; } }; @Override protected void onCreate(@Nullable Bundle savedInstanceState) { super.onCreate(savedInstanceState); this.setContentView(R.layout.activity_temp); } /** * 绑定服务 */ public void bindService(View view) { Intent viewServiceIntent = new Intent(this,RemoteViewsAIDLService.class); isBind = bindService(viewServiceIntent,remoteViewServiceConnection, Context.BIND_AUTO_CREATE); } /** * 更新UI */ public void UpdateUI(View view){ RemoteViews remoteViews = new RemoteViews(Temp2Activity.this.getPackageName(),R.layout.button_layout); Intent intentClick = new Intent(Temp2Activity.this,FirstActivity.class); PendingIntent openFirstActivity = PendingIntent.getActivity(Temp2Activity.this,0,intentClick,0); remoteViews.setOnClickPendingIntent(R.id.firstButton,openFirstActivity); Intent secondClick = new Intent(Temp2Activity.this,SecondActivity.class); PendingIntent openSecondActivity = PendingIntent.getActivity(Temp2Activity.this,0,secondClick,0); remoteViews.setOnClickPendingIntent(R.id.secondButton,openSecondActivity); remoteViews.setCharSequence(R.id.secondButton,"setText","想改就改"); try { remoteViewsManager.addRemoteView(remoteViews); } catch (RemoteException e) { e.printStackTrace(); } } @Override protected void onDestroy() { super.onDestroy(); if(isBind){ unbindService(remoteViewServiceConnection); isBind = false; } }}
AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.czhappy.remoteviewdemo"> <application android:allowBackup="true" android:icon="@mipmap/ic_launcher" android:label="@string/app_name" android:supportsRtl="true" android:theme="@style/AppTheme"> <activity android:name=".activity.MainActivity"> <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> <activity android:name=".activity.FirstActivity" /> <activity android:name=".activity.SecondActivity" /> <activity android:name=".activity.Temp2Activity" android:process=":remote2" /> <service android:name="com.czhappy.remoteviewdemo.service.RemoteViewsAIDLService" /> </application></manifest>
四、总结
RemoteViews就是为跨进程更新UI而生的，内部封装了很多方法用来实现跨进程更新UI。但这并不代表RemoteViews是就是万能的了，它也有不足之处，目前支持的布局和View有限
layout：
FrameLayout LinearLayout RelativeLayout GridLayout
View：
AnalogClock button Chronometer ImageButton ImageView ProgressBar TextView ViewFlipper ListView GridView StackView AdapterViewFlipper ViewStub
不支持自定义View 所以具体使用RemoteViews还是aidl或者BroadCastReceiver还得看实际的需求。
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。
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