Android开发代码片收集

以下片段收集自： http://blog.csdn.net/zhangjg_blog/article/details/27697665

不能保证代码片段没有bug, 在使用时需要经过测试.

1 切换系统中某个组件的状态,设置其enable或disable

 public void toggleComponent(View view){

         PackageManager pm = getPackageManager();

         String pkgName = "com.aa.activitytest";
         String comName = "com.aa.activitytest.SecondActivity";
         ComponentName componentName = new ComponentName(pkgName, comName);

         int state = pm.getComponentEnabledSetting(componentName);

         boolean isEnable = state == PackageManager.COMPONENT_ENABLED_STATE_ENABLED
                 || state == PackageManager.COMPONENT_ENABLED_STATE_DEFAULT;


         if(isEnable){
             pm.setComponentEnabledSetting(componentName, PackageManager.COMPONENT_ENABLED_STATE_DISABLED, PackageManager.DONT_KILL_APP);
         }else {
             pm.setComponentEnabledSetting(componentName, PackageManager.COMPONENT_ENABLED_STATE_ENABLED, PackageManager.DONT_KILL_APP);
         }
     }

2 列出系统中所有安装的app的信息

 PackageManager pm = getPackageManager();
 List<PackageInfo> packages = pm.getInstalledPackages(PackageManager.GET_UNINSTALLED_PACKAGES);

 for(PackageInfo packageInfo : packages){

     //应用图标
     Drawable icon = packageInfo.applicationInfo.loadIcon(pm);

     //标题
     CharSequence lable = packageInfo.applicationInfo.loadLabel(pm);

     //包名
     String packageName = packageInfo.packageName;

 }

3 将raw中的apk拷贝到/data/data/包名/files/中

 //1 拷贝raw中的apk文件
         InputStream in = null;
         OutputStream out = null;

         try {
             in = getResources().openRawResource(R.raw.dex_apk);
             out = this.openFileOutput("dex_apk.apk", Context.MODE_PRIVATE);
             copyFile(in, out);
         } catch (FileNotFoundException e) {
             e.printStackTrace();
         }finally {
             try {
                 if (in != null) in.close();
             }catch (IOException e){}

             try{
                 if (out != null) out.close();
             }catch (IOException e){}
         }

4 拷贝文件

 private void copyFile(InputStream in, OutputStream out){

     byte[] buffer = new byte[1024];
     int len = 0;

     try {
         while((len = in.read(buffer) ) != -1){
             out.write(buffer , 0 , len);
         }
     } catch (IOException e) {
         e.printStackTrace();
     }

 }

5 使用DexClassLoader加载 /data/data/包名/files/ 下的apk的classes.dex ， 并通过反射执行。 

 //2 加载并执行apk中的类
 String pkgDataPath = "/data/data/" + getPackageName();
 String optimizedDirectory = pkgDataPath + "/files/";
 String dexPath = optimizedDirectory + "dex_apk.apk";

 DexClassLoader dexClassLoader = new DexClassLoader(dexPath, optimizedDirectory, null, this.getClassLoader());

 try {
     Class personClazz = dexClassLoader.loadClass("com.aa.dexapk.Person");

     Object newInstance = personClazz.newInstance();

     Method method = personClazz.getMethod("doWork");

     method.invoke(newInstance);
 } catch (Exception e) {
     e.printStackTrace();
 }

6 动态加载其他已经安装的apk的dex文件， 并通过反射执行

 private void useDexClassLoader(){
             //创建一个意图，用来找到指定的apk
             Intent intent = new Intent("com.suchangli.android.plugin", null);
             //获得包管理器
             PackageManager pm = getPackageManager();
             List<ResolveInfo> resolveinfoes =  pm.queryIntentActivities(intent, 0);
             //获得指定的activity的信息
             ActivityInfo actInfo = resolveinfoes.get(0).activityInfo;

             //获得包名
             String pacageName = actInfo.packageName;
             //获得apk的目录或者jar的目录
             String apkPath = actInfo.applicationInfo.sourceDir;
             //dex解压后的目录,注意，这个用宿主程序的目录，android中只允许程序读取写自己
             //目录下的文件
             String dexOutputDir = getApplicationInfo().dataDir;

             //native代码的目录
             String libPath = actInfo.applicationInfo.nativeLibraryDir;
             //创建类加载器，把dex加载到虚拟机中
             DexClassLoader calssLoader = new DexClassLoader(apkPath, dexOutputDir, libPath,
                             this.getClass().getClassLoader());

             //利用反射调用插件包内的类的方法

             try {
                         Class<?> clazz = calssLoader.loadClass(pacageName+".Plugin1");

                         Object obj = clazz.newInstance();
                         Class[] param = new Class[2];
                         param[0] = Integer.TYPE;
                         param[1] = Integer.TYPE;

                         Method method = clazz.getMethod("function1", param);

                         Integer ret = (Integer)method.invoke(obj, 1,12);

                         Log.i("Host", "return result is " + ret);

                 } catch (ClassNotFoundException e) {
                         e.printStackTrace();
                 } catch (InstantiationException e) {
                         e.printStackTrace();
                 } catch (IllegalAccessException e) {
                         e.printStackTrace();
                 } catch (NoSuchMethodException e) {
                         e.printStackTrace();
                 } catch (IllegalArgumentException e) {
                         e.printStackTrace();
                 } catch (InvocationTargetException e) {
                         e.printStackTrace();
                 }
     }

7 获取其他包中的资源（pm.getResourcesForApplication(pkgName) )

 Intent intent = new Intent("com.suchangli.android.plugin", null);
         //获得包管理器
         PackageManager pm = getPackageManager();
         List<ResolveInfo> resolveinfoes =  pm.queryIntentActivities(intent, 0);
         //获得指定的activity的信息
         ActivityInfo actInfo = resolveinfoes.get(0).activityInfo;

         //获得包名
         String pacageName = actInfo.packageName;

         try {
             Resources res = pm.getResourcesForApplication(pacageName);

             int id = 0;
             id = res.getIdentifier("ic_launcher", "drawable", pacageName);
             Log.i("", "resId is " + id);


         } catch (NameNotFoundException e) {
             e.printStackTrace();
         }

8 Context.getDir创建并返回目录

Context.getDir（“mydir”） 返回的目录的绝对路径是 ：  /data/data/package_name/app_mydir 。 

9 获取Activity的图标

 private Bitmap getIconForActivity(Context context, String packageName, String activityName){

     ComponentName activityComp = new ComponentName(packageName, activityName);
     PackageManager pm = context.getPackageManager();

     Intent intentToResolve = new Intent();
     intentToResolve.setComponent(activityComp);

     ResolveInfo resolveInfo = pm.resolveActivity(intentToResolve, 0);

     Drawable iconDrawable = resolveInfo.activityInfo.loadIcon(pm);

     return Utilities.createIconBitmap( iconDrawable, context);
 }

其中Utilities为Launcher中的工具类。 

10 获取当前app的签名信息：

 /**
  * get signature of current package
  * @param context
  * @return signature, null if there is no signature
  */
 public static String getSignature(Context context){

     Log.i(TAG, "SignatureUtils.getSignature");

     PackageManager pm = context.getPackageManager();
     String pkgName = context.getPackageName();

     try {
         PackageInfo pi = pm.getPackageInfo(pkgName, PackageManager.GET_SIGNATURES);
         Signature[] signatures = pi.signatures;

         if(signatures != null && signatures.length > 0){

             String signature =  signatures[0].toCharsString();
             Log.i(TAG, "Signature of current package is : " + signature);

             return  signature;
         }
     } catch (PackageManager.NameNotFoundException e1) {
         e1.printStackTrace();
     }

     return null;
 }

11 获取apk文件的签名信息（未安装， 只是一个apk文件）

 /**
  * get signature of an apk file
  * this method will execute quit a long time, so it is suitable to call it in sub thread
  * @param context
  * @param apkFilePath
  * @return signature , null if there is no signature , or apkFilePath is wrong
  */
 public static String getSignatureOfApk(Context context, String apkFilePath){
     Log.i(TAG, "SignatureUtils.getSignatureOfApk");

     if (TextUtils.isEmpty(apkFilePath)) return null;

     PackageManager pm = context.getPackageManager();


     PackageInfo pi = pm.getPackageArchiveInfo(apkFilePath, PackageManager.GET_SIGNATURES);
     Signature[] signatures = pi.signatures;

     if(signatures != null && signatures.length > 0){

         String signature =  signatures[0].toCharsString();
         Log.i(TAG, "Signature of " + apkFilePath + " is : " + signature);

         return  signature;
     }


     return null;
 }

12 获取apk文件的权限信息

 public static List<PermissionInfo> getApkPermissions(String apkFile, PackageManager pm){

      if(DEBUG) Log.i(TAG, "PackageUtils.getApkPermissions");

      List<PermissionInfo> permissionInfos = new ArrayList<PermissionInfo>();

      PackageInfo packageInfo =  pm.getPackageArchiveInfo(apkFile, PackageManager.GET_PERMISSIONS);

      String[] permissions = packageInfo.requestedPermissions;

      for(String permName : permissions ){

          try {
              PermissionInfo permissionInfo = pm.getPermissionInfo(permName, 0);
              permissionInfos.add(permissionInfo);

          } catch (PackageManager.NameNotFoundException e) {
              e.printStackTrace();
          }
      }

      return permissionInfos;