Android检查SD卡是否可读写，androidsd卡可读写,因为external s

Android检查SD卡是否可读写，androidsd卡可读写,因为external s

因为external storage可能是不可用的，比如遇到SD卡被拔出等情况时。因此在访问之前应对其可用性进行检查。我们可以通过执行 getExternalStorageState()来查询external storage的状态。若返回状态为MEDIA_MOUNTED, 则可以读写。```java/ Checks if external storage is available for read and write /public boolean isExternalStorageWritable() { String state = Environment.getExternalStorageState(); if (Environment.MEDIA_MOUNTED.equals(state)) { return true; } return false;}

/ Checks if external storage is available to at least read /public boolean isExternalStorageReadable() { String state = Environment.getExternalStorageState(); if (Environment.MEDIA_MOUNTED.equals(state) || Environment.MEDIA_MOUNTED_READ_ONLY.equals(state)) { return true; } return false;}```