问题
In android KitKat there are some limitations for writing to SDcard.
So my question: Is it always permitted to write to Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES) even in KitKat?
回答1:
Is it always permitted to write to Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES) even in KitKat?
If your app has requested the WRITE_EXTERNAL_STORAGE permission, then yes, as getExternalStoragePublicDirectory() points to external storage, which is not removable storage ("SDCard") on the vast majority of devices.
回答2:
You first need to understand concepts of Android Storage.
Then you will understand that Environment.getExternalStorageDirectory() or something like that is about primary external storage. And it has nothing to do with Android APIs whether it is younger or older than KitKat.
回答3:
To get the internal SD card you can use
String extStore = System.getenv("EXTERNAL_STORAGE");
File f_exts = new File(extStore);
To get the external SD card you can use
String secStore = System.getenv("SECONDARY_STORAGE");
File f_secs = new File(secStore);
On running the code
extStore = "/storage/emulated/legacy"
secStore = "/storage/extSdCarcd"
works perfectly!
refer following Link , I think ur question has been answered already check this...
Android Open External Storage directory(sdcard) for storing file
来源：https://stackoverflow.com/questions/29513004/android-kitkat-sdcard-write-permission