androidSD卡操作

1.获取SD卡目录：File file = Environment.getExternalStorageDirectory();

2.获取SD卡路径：String path = Environment.getExternalStorageDirectory().getPath();

3.获取SD卡状态（挂在还是卸载）Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED),SD卡可用

4.获取SD开总大小：Environment.getExternalStorageDirectory().getTotalSpace()

5.获取SD卡可用大小（字节数）：Environment.getExternalStorageDirectory().getFreeSpace()

6.格式化存储字节数大小用（MB表示）：String fileSize = Formatter.formatFileSize(this, size);

7.访问sd卡需要添加权限：

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