探秘腾讯Android手机游戏平台之不安装游戏APK直接启动法

喜欢ヅ旅行 2022-07-13 15:10 147阅读 0赞

### 前言 ###

相信这样一个问题，大家都不会陌生，

> “有什么的方法可以使Android的程序APK不用安装，而能够直接启动”。

发现最后的结局都是不能实现这个美好的愿望，而腾讯Android手机游戏平台却又能实现这个功能，下载的连连看，五子棋都没有安装过程，但是都能直接运行，这其中到底有什么“玄机”呢，也有热心童鞋问过我这个问题，本文就为大家来揭开这个谜团。

> ## 重要说明 ##
> 
> 在实践的过程中大家都会发现资源引用的问题，这里重点声明两点：  
> 1. 资源文件是不能直接inflate的，如果简单的话直接在程序中用代码书写。  
> 2. 资源文件是不能用R来引用的，因为上下文已经不同了，腾讯的做法是将资源文件打包(\*.pak文件和APK打包在一起)，虽然APK是没有进行安装，但是资源文件是另外解压到指定文件夹下面的，然后将文件夹的地址传给了第三方应用程序，这样第三方应用程序通过File的inputstream流还是可以读取和使用这些资源的。

### 实践 ###

我实现了一个小小的Demo，麻雀虽小五脏俱全，为了突出原理，我就尽量简化了程序，通过这个实例来让大家明白后台的工作原理。

1.  下载demo的apk程序[apks][]，其中包括了两个apk，分别是A和B
2.  这两个APK可分别安装和运行，A程序界面只显示一个Button，B程序界面会动态显示当前的时间
3.  下面的三幅图片分别为直接启动运行A程序（安装TestA.apk），直接启动运行B程序（安装TestB.apk）和由A程序动态启动B程序（安装TestA.apk，TestB.apk不用安装，而是放在/mnt/sdcard/目录中，即 SD卡上）的截图，细心的同学可以停下来观察一下他们之间的不同  
    ![device-2011-09-18-A][]![device-2011-09-18-B][]![device-2011-09-18-AB][]
4.  后两幅图片的不同，也即Title的不同，则解释出了我们将要分析的后台实现原理的机制

### 实现原理 ###

最能讲明白道理的莫过于源码了，下面我们就来分析一下A和B的实现机制，首先来分析TestA.apk的主要代码实现：

**代码解析**：这就是OnCreate函数要做的事情，装载view界面，绑定button事件，大家都熟悉了，还有就是设置程序B的放置路径，因为我程序中代码是从/mnt/sdcard/TestB.apk中动态加载，这也就是为什么要让大家把TestB.apk放在SD卡上面的原因了。关键的函数就是最后一个了LoadAPK，它来实现动态加载B程序。

<table style="width:686px; border:none; border-spacing:0px; line-height:18px; margin:0px; font-family:monospace; padding:0px"> 
 <tbody> 
 <tr style="background-color:rgb(255,255,255)"> 
 <td style="font-size:14px; padding:0px; border:none; margin:0px 10px; background-color:rgb(238,238,238); line-height:1.4; text-align:right; width:41px"> <pre style="line-height:1.4; font-size:12px; font-family:Consolas,&quot;Andale Mono&quot;,Courier,&quot;Courier New&quot;,monospace; background:transparent; overflow:auto; padding:0px; border:none; clear:both; margin:0px 10px">1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
</pre> </td> 
 <td style="font-size:14px; padding:0px; border-top:none; border-bottom:none; border-right:none; border-left:1px solid rgb(159,159,159); margin:0px 10px; line-height:1.4"> <pre style="line-height:1.4; font-size:12px; font-family:Consolas,&quot;Andale Mono&quot;,Courier,&quot;Courier New&quot;,monospace; background:transparent; overflow:auto; padding:0px; border:none; clear:both; margin:0px 5px">&nbsp; &nbsp; public void LoadAPK(Bundle paramBundle, String dexpath, String dexoutputpath) {
 
&nbsp; &nbsp; &nbsp; &nbsp; ClassLoader localClassLoader = ClassLoader.getSystemClassLoader();
&nbsp; &nbsp; &nbsp; &nbsp; DexClassLoader localDexClassLoader = new DexClassLoader(dexpath,
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; dexoutputpath, null, localClassLoader);
&nbsp; &nbsp; &nbsp; &nbsp; try {
 
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; PackageInfo plocalObject = getPackageManager()
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; .getPackageArchiveInfo(dexpath, 1);
&nbsp;
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; if ((plocalObject.activities != null)
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &amp;&amp; (plocalObject.activities.length &gt; 0)) {
 
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; String activityname = plocalObject.activities[0].name;
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; Log.d(TAG, "activityname = " + activityname);
&nbsp;
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; Class localClass = localDexClassLoader.loadClass(activityname);
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; Constructor localConstructor = localClass
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; .getConstructor(new Class[] {
 });
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; Object instance = localConstructor.newInstance(new Object[] {
 });
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; Log.d(TAG, "instance = " + instance);
&nbsp;
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; Method localMethodSetActivity = localClass.getDeclaredMethod(
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; "setActivity", new Class[] {
 Activity.class });
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; localMethodSetActivity.setAccessible(true);
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; localMethodSetActivity.invoke(instance, new Object[] {
 this });
&nbsp;
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; Method methodonCreate = localClass.getDeclaredMethod(
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; "onCreate", new Class[] {
 Bundle.class });
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; methodonCreate.setAccessible(true);
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; methodonCreate.invoke(instance, new Object[] {
 paramBundle });
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; }
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; return;
&nbsp; &nbsp; &nbsp; &nbsp; } catch (Exception ex) {
 
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; ex.printStackTrace();
&nbsp; &nbsp; &nbsp; &nbsp; }
&nbsp; &nbsp; }</pre> </td> 
 </tr> 
 </tbody> 
</table>

**代码解析**：这个函数要做的工作如下：加载B程序的APK文件，通过类加载器DexClassLoader来解析APK文件，这样会在SD卡上面生成一个同名的后缀为dex的文件，例如/mnt/sdcard/TestB.apk==>/mnt/sdcard/TestB.dex,接下来就是通过java反射机制，动态实例化B中的Activity对象，并依次调用了其中的两个函数，分别为setActivity和onCreate.看到这里，大家是不是觉得有点奇怪，Activity的启动函数是onCreate，为什么要先调用setActivity，而更奇怪的是setActivity并不是系统的函数，确实，那是我们自定义的，这也就是核心的地方。

好了带着这些疑问，我们再来分析B程序的主代码：

**代码解析**：看完程序B的实现机制，大家是不是有种恍然大悟的感觉，这根本就是“偷梁换柱”嘛，是滴，程序B动态借用了程序A的上下文执行环境，这也就是上面后两幅图的差异，最后一幅图运行的是B的程序，但是title表示的却是A的信息，而没有重新初始化自己的，实际上这也是不可能的，所以有些童鞋虽然通过java的反射机制，正确呼叫了被调程序的onCreate函数，但是期望的结果还是没有出现，原因就是这个上下文环境没有正确建立起来，但是若通过startActivity的方式来启动APK的话，android系统会替你建立正确的执行时环境，所以就没问题。至于那个TBSurfaceView，那就是自定义的一个view画面，动态画当前的时间

<table style="width:686px; border:none; border-spacing:0px; line-height:18px; margin:0px; font-family:monospace; padding:0px"> 
 <tbody> 
 <tr style="background-color:rgb(255,255,255)"> 
 <td style="font-size:14px; padding:0px; border:none; margin:0px 10px; background-color:rgb(238,238,238); line-height:1.4; text-align:right; width:41px"> <pre style="line-height:1.4; font-size:12px; font-family:Consolas,&quot;Andale Mono&quot;,Courier,&quot;Courier New&quot;,monospace; background:transparent; overflow:auto; padding:0px; border:none; clear:both; margin:0px 10px">1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
</pre> </td> 
 <td style="font-size:14px; padding:0px; border-top:none; border-bottom:none; border-right:none; border-left:1px solid rgb(159,159,159); margin:0px 10px; line-height:1.4"> <pre style="line-height:1.4; font-size:12px; font-family:Consolas,&quot;Andale Mono&quot;,Courier,&quot;Courier New&quot;,monospace; background:transparent; overflow:auto; padding:0px; border:none; clear:both; margin:0px 5px">public class TBSurfaceView extends SurfaceView implements Callback, Runnable {
 
&nbsp; &nbsp; private SurfaceHolder sfh;
&nbsp; &nbsp; private Thread th;
&nbsp; &nbsp; private Canvas canvas;
&nbsp; &nbsp; private Paint paint;
&nbsp;
&nbsp; &nbsp; public TBSurfaceView(Context context) {
 
&nbsp; &nbsp; &nbsp; &nbsp; super(context);
&nbsp; &nbsp; &nbsp; &nbsp; th = new Thread(this);
&nbsp; &nbsp; &nbsp; &nbsp; sfh = this.getHolder();
&nbsp; &nbsp; &nbsp; &nbsp; sfh.addCallback(this);
&nbsp; &nbsp; &nbsp; &nbsp; paint = new Paint();
&nbsp; &nbsp; &nbsp; &nbsp; paint.setAntiAlias(true);
&nbsp; &nbsp; &nbsp; &nbsp; paint.setColor(Color.RED);
&nbsp; &nbsp; &nbsp; &nbsp; this.setKeepScreenOn(true);
&nbsp; &nbsp; }
&nbsp;
&nbsp; &nbsp; public void surfaceCreated(SurfaceHolder holder) {
 
&nbsp; &nbsp; &nbsp; &nbsp; th.start();
&nbsp; &nbsp; }
&nbsp;
&nbsp; &nbsp; private void draw() {
 
&nbsp; &nbsp; &nbsp; &nbsp; try {
 
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; canvas = sfh.lockCanvas();
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; if (canvas != null) {
 
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; canvas.drawColor(Color.WHITE);
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; canvas.drawText("Time: " + System.currentTimeMillis(), 100,
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 100, paint);
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; }
&nbsp; &nbsp; &nbsp; &nbsp; } catch (Exception ex) {
 
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; ex.printStackTrace();
&nbsp; &nbsp; &nbsp; &nbsp; } finally {
 
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; if (canvas != null) {
 
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; sfh.unlockCanvasAndPost(canvas);
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; }
&nbsp; &nbsp; &nbsp; &nbsp; }
&nbsp; &nbsp; }
&nbsp;
&nbsp; &nbsp; public void run() {
 
&nbsp; &nbsp; &nbsp; &nbsp; while (true) {
 
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; draw();
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; try {
 
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; Thread.sleep(100);
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; } catch (InterruptedException e) {
 
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; e.printStackTrace();
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; }
&nbsp; &nbsp; &nbsp; &nbsp; }
&nbsp; &nbsp; }
&nbsp;
&nbsp; &nbsp; public void surfaceChanged(SurfaceHolder holder, int format, int width,
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; int height) {
 
&nbsp; &nbsp; }
&nbsp;
&nbsp; &nbsp; public void surfaceDestroyed(SurfaceHolder holder) {
 
&nbsp; &nbsp; }
}</pre> </td> 
 </tr> 
 </tbody> 
</table>

### 腾讯游戏平台解析 ###

说了这么多，都是背景，O(∩\_∩)O哈哈~

其实腾讯游戏平台就是这么个实现原理，我也是通过它才学习到这种方式的，还得好好感谢感谢呢。

腾讯Android游戏平台的游戏分成两类，第一类是腾讯自主研发的，像斗地主，五子棋，连连看什么的，所以实现机制就如上面的所示，A代表游戏大厅，B代表斗地主类的小游戏。第二类是第三方软件公司开发的，可就不能已这种方式来运作了，毕竟腾讯不能限制别人开发代码的方式啊，所以腾讯就开放了一个sdk包出来，让第三方应用可以和游戏大厅相结合，具体可参见[QQ游戏中心开发者平台][QQ]，但这同时就损失了一个优点，那就是第三方开发的游戏要通过安装的方式才能运行。

### 结论 ###

看到这里，相信大家都比较熟悉这个背后的原理了吧，也希望大家能提供更好的反馈信息！

程序源码下载[source][]

转帖：http://blog.zhourunsheng.com/2011/09/%E6%8E%A2%E7%A7%98%E8%85%BE%E8%AE%AFandroid%E6%89%8B%E6%9C%BA%E6%B8%B8%E6%88%8F%E5%B9%B3%E5%8F%B0%E4%B9%8B%E4%B8%8D%E5%AE%89%E8%A3%85%E6%B8%B8%E6%88%8Fapk%E7%9B%B4%E6%8E%A5%E5%90%AF%E5%8A%A8%E6%B3%95/

[apks]: http://carey.u.qiniudn.com/uploads/2011/09/apks.zip
[device-2011-09-18-A]: http://carey.u.qiniudn.com/uploads/2011/09/device-2011-09-18-A-200x300.png
[device-2011-09-18-B]: http://carey.u.qiniudn.com/uploads/2011/09/device-2011-09-18-B-200x300.png
[device-2011-09-18-AB]: http://carey.u.qiniudn.com/uploads/2011/09/device-2011-09-18-AB-200x300.png
[QQ]: http://dev.g.qq.com/res_sdk.html
[source]: http://carey.u.qiniudn.com/uploads/2011/09/source.zip