以前获取应用的大小是用
PackageManager mPackageManager= getPackageManager();
try {Method getPackageSizeInfoMethod = PackageManager.class.getDeclaredMethod("getPackageSizeInfo", String.class,
IPackageStatsObserver.class);
getPackageSizeInfoMethod.invoke(mPackageManager, packageInfo.packageName,new MyObserver());
} catch (Exception e) {
}
class MyObserver extends IPackageStatsObserver.Stub {
@Override
public void onGetStatsCompleted(PackageStats pStats, boolean succeeded)
throws RemoteException {
long cacheSize = pStats.cacheSize;
String packageName = pStats.packageName;
String formatFileSize = Formatter.formatFileSize(
getApplicationContext(), cacheSize);
System.out.println(packageName + ":" + formatFileSize);
}
}
但在4.2后 PackageManager.getPackageSizeInfo(String packageName, IPackageStatsObserver observer)不可用，
改为PackageManager.getPackageSizeInfo(String packageName, int userHandle, IPackageStatsObserver observer),
至于增加的参数userHandle的解释是：The user whose size information should be retrieved。
这个userHandle怎么来？ 通过系统类的UserHandle.myUserId()获取；
Method myUserId = UserHandle.class.getDeclaredMethod("myUserId");
int userID = (Integer) myUserId.invoke(mPackageManager,null);
获取了以后就可以使用新的getPackageSizeInfo函数了。
getPackageSizeInfoMethod.invoke(mPackageManager,packageInfo.packageName, userID, new MyObserver() );
(原)android4.2以后获取应用程序和缓存大小的方法（源码有改变）
原文：http://www.cnblogs.com/liuying3013/p/4280054.html