Android 判断SD卡是否存在及容量查询

Android 判断SD卡是否存在及容量查询的简单方法如下：
首先要在AndroidManifest.xml中增加SD卡访问权限

<!-- 在SDCard中创建与删除文件权限 -->
<uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS"/>
<!-- 往SDCard写入数据权限 -->
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

SD卡是否存在

 private boolean ExistSDCard() {
	  if (android.os.Environment.getExternalStorageState().equals(
	    android.os.Environment.MEDIA_MOUNTED)) {
	   return true;
	  } else
	   return false;
	 }

SD卡剩余空间

 public long getSDFreeSize(){
      //取得SD卡文件路径
      File path = Environment.getExternalStorageDirectory(); 
      StatFs sf = new StatFs(path.getPath()); 
      //获取单个数据块的大小(Byte)
      long blockSize = sf.getBlockSize(); 
      //空闲的数据块的数量
      long freeBlocks = sf.getAvailableBlocks();
      //返回SD卡空闲大小
      //return freeBlocks * blockSize;  //单位Byte
      //return (freeBlocks * blockSize)/1024;   //单位KB
      return (freeBlocks * blockSize)/1024 /1024; //单位MB
    }	

SD卡总容量

 public long getSDAllSize(){
      //取得SD卡文件路径
      File path = Environment.getExternalStorageDirectory(); 
      StatFs sf = new StatFs(path.getPath()); 
      //获取单个数据块的大小(Byte)
      long blockSize = sf.getBlockSize(); 
      //获取所有数据块数
      long allBlocks = sf.getBlockCount();
      //返回SD卡大小
      //return allBlocks * blockSize; //单位Byte
      //return (allBlocks * blockSize)/1024; //单位KB
      return (allBlocks * blockSize)/1024/1024; //单位MB
    }