以Android本机代码写入外部SD卡时，fopen失败

Question

When I am trying to write into external SDcard from android native code, I am getting permission denied in fopen.

mFp = fopen("/storage/extSdCard/Output/test.txt", "wb");

if I print strerror(errno) it gives ->

fopen(/storage/extSdCard/Output/test.txt) failed: Permission denied

Please note that I have also given the permissions in my Application manifest :

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />  
....
</manifest>

and also :

String state = Environment.getExternalStorageState();
        if (Environment.MEDIA_MOUNTED.equals(state)) {
            return true;
        }

is returing true.

Answer 1

请检查外部存储设备是插入的外部卡还是设备随附的sdcard。如果它是设备本身随附的sdcard，请尝试将路径设置为“ / mnt / drive_path”，并检查您的本机方法是否为能够写入您的存储。