[Android] 檢查SD卡是否可以讀寫

出自官方的程式碼

//sdcard是否安裝
boolean mExternalStorageAvailable = false;
//sdcar是否可以寫入
boolean mExternalStorageWriteable = false;

String state = Environment.getExternalStorageState();

if(Environment.MEDIA_MOUNTED.equals(state)) {
  //可以讀取和寫入sdcar
  // We can read and write the media
  mExternalStorageAvailable = mExternalStorageWriteable = true;

} else if (Environment.MEDIA_MOUNTED_READ_ONLY.equals(state)) {
  //只能讀不能寫
  // We can only read the media
  mExternalStorageAvailable = true;
  mExternalStorageWriteable = false;

} else {
  //其他原因
  // Something else is wrong. It may be one of many other states, but all we need
  // to know is we can neither read nor write
  mExternalStorageAvailable = mExternalStorageWriteable = false;
}

引用來源