《笔记》Android 获取第三方应用及查看应用信息、apk大小、缓存、存储，以及第三方清除缓存

获取应用相关信息：

PS:manifest标签中设置以下属性表示系统应用
android:process="system" android:sharedUserId="android.uid.system"

//获取所有应用（非系统apk，有些应用获取不到）
List<ApplicationInfo> installedApplications = getPackageManager().getInstalledApplications(PackageManager.GET_META_DATA);

获取缓存，apk体积，存储大小，版本号等：

    //全局变量，保存当前查询包得信息
    private long cachesize ; //缓存大小
    private long datasize  ;  //数据大小
    private long codesize  ;  //应用程序大小
    private long totalsize ; //总大小

    //获取相关数据
    public void  queryPacakgeSize() {
        getPackageSizeInfo(new PackageStatsObserver());
    }
    /** 
     * 8.0及以下回调使用
     * */
    private class PackageStatsObserver extends IPackageStatsObserver.Stub {
        @Override
        public void onGetStatsCompleted(PackageStats pStats, boolean succeeded) throws RemoteException {
            Log.d("hsh", "packageName = "+pStats.packageName+"---"+(pStats.cacheSize + pStats.externalCacheSize));
            // 在此处理 PackageStats 数据
            // TODO Auto-generated method stub
            cachesize = pStats.cacheSize  ; //缓存大小
            datasize = pStats.dataSize  ;  //数据大小
            codesize = pStats.codeSize  ;  //应用程序大小
            totalsize = cachesize + datasize + codesize ;
//            Log.i("hsh", "cachesize--->"+cachesize+" datasize---->"+datasize+ " codeSize---->"+codesize)  ;
            setViewData();
        }
    }
    /** 
     * 获取apk体积，内存，缓存信息
     * */
    private void getPackageSizeInfo( IPackageStatsObserver.Stub observer) {
        Context context = SettingApplication.getInstance();
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            final StorageStatsManager storageStatsManager = (StorageStatsManager) context.getSystemService(Context.STORAGE_STATS_SERVICE);
            final StorageManager storageManager = (StorageManager) context.getSystemService(Context.STORAGE_SERVICE);
            try {
                StorageStats storageStats = storageStatsManager.queryStatsForPackage(applicationInfo.storageUuid,applicationInfo.packageName, UserHandle.getUserHandleForUid(applicationInfo.uid));
//                StorageStats storageStats = storageStatsManager.queryStatsForUid(applicationInfo.storageUuid, applicationInfo.uid);
                cachesize = storageStats.getCacheBytes();//缓存大小
                datasize = storageStats.getDataBytes();//数据大小
                codesize = storageStats.getAppBytes();//应用程序大小
                totalsize = cachesize + datasize + codesize ;
//                Log.i("hsh", "packageName:"+this.applicationInfo+",,"+cachesize + ",," + datasize + ",," + codesize+",,"+totalsize);
                setViewData();
            } catch (Exception e) {
                e.printStackTrace();
            }
        } else {
            //9.0及以上此方法无效，会抛出错误
            try {
                Method method = pm.getClass().getMethod("getPackageSizeInfo", String.class, IPackageStatsObserver.class);
                method.invoke(pm, this.applicationInfo.packageName, observer);
            }  catch (Exception e) {
                e.printStackTrace();
            }
        }
    }

    private void  setViewData(){
        try {
            ApplicationInfo app = mContext.getPackageManager().getApplicationInfo(this.applicationInfo.packageName, 0);
            PackageInfo packageInfo = pm.getPackageInfo(app.packageName, PackageManager.GET_SIGNATURES);
            //赋值缓存
            tvAppCacheData.setText(formateFileSize(datasize));
            //有些apk获取不到内存大小，所以通过file.length()去获取
            if (!TextUtils.isEmpty(applicationInfo.sourceDir)) {
                File file = new File(applicationInfo.sourceDir);
                tvAppMemoryData.setText(formateFileSize(file.length()));//赋值apk大小
            } else {
                tvAppMemoryData.setText(formateFileSize(codesize));
            }
            //获取版apk其他应用消息，比如说版本versionCode，versionName等
            tvAppVersionCode.setText(packageInfo.versionName);
        } catch (PackageManager.NameNotFoundException e) {
            e.printStackTrace();
        }

    }
    //系统函数，字符串转换 long -String (kb)
    private String formateFileSize(long size){
        return Formatter.formatFileSize(mContext, size);
    }

清除缓存，通过反射deleteApplicationCacheFiles清除缓存数据，看了下没什么效果改成clearApplicationUserData后测试可以：

  public  void deleteDir(String packageName) {
        try {
            Method method = pm.getClass().getMethod(
                    "clearApplicationUserData",
                    String.class,
                    IPackageDataObserver.class
            );
            // 指定目标应用包名（如 com.example.app）
            method.invoke(pm, packageName, new IPackageDataObserver.Stub() {
                @Override
                public void onRemoveCompleted(String pkg, boolean success) {
                    // 清理完成回调
                    Log.i(TAG, "onRemoveCompleted: "+pkg+"====="+success);
                    ToastUtil.s(R.string.str_clear_cache);
                }
            });
        } catch (Exception e) {
            e.printStackTrace();
        }

    }

PS:查看底层代码发现8.0以后被强制抛出异常