枚举安装的应用并查询应用的包名和对应的APK文件路径

        // Iterate Android packages

        List<PackageInfo> packages = getPackageManager().getInstalledPackages(PackageManager.GET_ACTIVITIES |

                PackageManager.GET_GIDS | PackageManager.GET_CONFIGURATIONS |

                PackageManager.GET_INSTRUMENTATION | PackageManager.GET_PERMISSIONS |

                PackageManager.GET_PROVIDERS | PackageManager.GET_RECEIVERS |

                PackageManager.GET_SERVICES | PackageManager.GET_SIGNATURES);

        for (int i = 0; i < packages.size(); i++) {

            PackageInfo package_info = packages.get(i);

            String package_name = package_info.packageName;

            package_name = package_name.trim().toLowerCase();

            Log.i(TAG, "Got package: " + package_name);

            try {

                ApplicationInfo app_info = getPackageManager().getApplicationInfo(package_name,

                        PackageManager.GET_META_DATA | PackageManager.GET_SHARED_LIBRARY_FILES);

                Log.i(TAG, "Package apk file path: " + app_info.sourceDir);

            } catch (NameNotFoundException e) {

                e.printStackTrace();

            }

        }

当然，也可以硬来：

// Iterate folder, this needs "root" privilege
File root_dir = new File("/data/app");
File[] files = root_dir.listFiles();
for (int i = 0; i < files.length; i++) {
    if (files[i].isFile()) {
        String filename = files[i].getName();
        filename = filename.trim().toLowerCase();
        Log.i(TAG, "Got file under /data/app: " + filename);

直接遍历/data/app或者/system/app目录。不过这就需要root权限，而且能取到的信息远远少于使用PackageManager。