Android安卓中循环录像并检测内存卡容量

/**	 * 循环录像，当内存卡容量少于300M时，自动删除视频列表里面的第一个文件	 */	private void xunhuanluxiang() {		if (Environment.getExternalStorageState().equals(				Environment.MEDIA_MOUNTED)) {			File path = Environment.getExternalStorageDirectory();			// 取得sdcard文件路径			StatFs statfs = new StatFs(path.getPath());			// 获取block的SIZE			long blocSize = statfs.getBlockSize();			// 获取BLOCK数量			long totalBlocks = statfs.getBlockCount();			// 己使用的Block的数量			long availaBlock = statfs.getAvailableBlocks();			// 获取当前可用内存容量，单位：MB			long sd = availaBlock * blocSize / 1024 / 1024;			if (sd < 300) {				String filepath = (Environment.getExternalStorageDirectory()						.getAbsolutePath() + "/video/");				File file = new File(filepath);				if (!file.exists()) {					file.mkdirs();				}				File[] files = file.listFiles();				if (files.length > 0) {					String childFile[] = file.list();					String dele = (filepath + childFile[0]);					File file2 = new File(dele);					file2.delete();				}			}		} else if (Environment.getExternalStorageState().equals(				Environment.MEDIA_REMOVED)) {			Toast.makeText(this, "请插入内存卡", Toast.LENGTH_SHORT).show();		}	}