这是@Josef Pfleger 的附加答案，供评论
“我发现某些设备没有 getPackageSizeInfo()，然后你会得到这个 java.lang.NoSuchMethodException: getPackageSizeInfo()”@ATom 2011 年 11 月 29 日 15:56。
api 16(Build.VERSION.SDK_INT >16)之后，方法
PackageManager.getPackageSizeInfo(String packageName, IPackageStatsObserver observer);
改成：
PackageManager.getPackageSizeInfo(String packageName, int userHandle, IPackageStatsObserver observer);
而新添加的参数userHandle的解释是：应该检索其尺寸信息的用户。
所以我们应该这样做：
int sysVersion= Build.VERSION.SDK_INT;
if (pkgName != null) {// packageName
PackageManager pm = getPackageManager();
try {
Class<?> clz = pm.getClass();
if (sysVersion>16) {
Method myUserId=UserHandle.class.getDeclaredMethod("myUserId");//ignore check this when u set ur min SDK < 17
int userID = (Integer) myUserId.invoke(pm);
Method getPackageSizeInfo = clz.getDeclaredMethod(
"getPackageSizeInfo", String.class,int.class,
IPackageStatsObserver.class);//remember add int.class into the params
getPackageSizeInfo.invoke(pm,pkgName, userID, new PkgSizeObserver());
} else {//for old API
Method getPackageSizeInfo = clz.getDeclaredMethod(
"getPackageSizeInfo", String.class,
IPackageStatsObserver.class);
getPackageSizeInfo.invoke(pm, pkgName, new PkgSizeObserver());
}
} catch (Exception ex) {
Log.e(TAG, "NoSuchMethodException");
ex.printStackTrace();
throw ex;}
需要回调的类如：
private class PkgSizeObserver extends IPackageStatsObserver.Stub {
/***
* @param pStatus
* @param succeeded
*/
@Override
public void onGetStatsCompleted(PackageStats pStats, boolean succeeded)
throws RemoteException {
cachesize = pStats.cacheSize;//remember to declare these fields
datasize = pStats.dataSize;
codesize = pStats.codeSize;
totalsize = cachesize + datasize + codesize;
Log.i("123","cachesize--->" + cachesize + " datasize---->"
+ datasize + " codeSize---->" + codesize);
}
}
并使用此方法解析long2string，然后您可以看到xx MB 而不是long 像2342334 :)
private String formateFileSize(long size) {
return Formatter.formatFileSize(MainActivity.this, size);
}