我一直在嘗試以/sdcard編程方式創(chuàng)建目錄，但無法正常工作。以下代碼始終輸出directory not created.boolean success = (new File("/sdcard/map")).mkdir(); if (!success) {    Log.i("directory not created", "directory not created");} else {    Log.i("directory created", "directory created");}