Android SD卡工具类，androidsd工具类,Android的mani

Android SD卡工具类，androidsd工具类,Android的mani

Android的manifest.xml文档中声名权限： ```java<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS"/>

  判断SDcard是否可以用 ```java    public static boolean isSdCardExists() {              if (android.os.Environment.getExternalStorageState().equals(                      android.os.Environment.MEDIA_MOUNTED)) {                  return true;              } else {                  Log.e(" ", "the Sdcard is not exists");                  return false;              }          }  

获取SD卡总大小```java public static String getSdCardTotalSize() {
if (!isSdCardExists())
return "";
File path = Environment.getExternalStorageDirectory();
StatFs stat = new StatFs(path.getPath());
long blockSize = stat.getBlockSize();
long availableBlocks = stat.getBlockCount();
return String.valueOf((availableBlocks * blockSize) / 1024 / 1024);
}

 获取SD卡可用大小 ```java    public static String getSdcardAvailbleSize() {             if (!isSdCardExists())                 return "";             File path = Environment.getExternalStorageDirectory();             StatFs stat = new StatFs(path.getPath());             long blockSize = stat.getBlockSize();             long availableBlocks = stat.getAvailableBlocks();             return String.valueOf((availableBlocks * blockSize) / 1024 / 1024);         }  

获取根目录路径```java public static String getRootPath() {
if (!isSdCardExists())
return "";
return Environment.getExternalStorageDirectory().getPath();
}

获取根目录文件列表```java    public static File[] getRootFiles() {             if (getRootPath().equals(""))                 return null;             List<File> files = new ArrayList<File>();             File file = new File(getRootPath());             return file.listRoots();         }