用指定url获取byte数组报：An invalid request URI was provided. The request URI must either be an absolute URI or BaseAddress must be set. 这是没有遵循http协议，在路径中http:后面必须要有两个斜杆
比如http:/xxx.xxx.xxx是行不通的，必须是http://xxx.xxx.xxx

  	byte[] Bytes = mywebclient.GetByteArrayAsync("http:/xxx.xxx.xxx").Result;
    string eurl = Convert.ToBase64String(Bytes);
  	byte[] Bytes = mywebclient.GetByteArrayAsync("http://xxx.xxx.xxx").Result;
    string eurl = Convert.ToBase64String(Bytes);
这里我是利用图片路径获取图片转为base64
                    An invalid request URI was provided. The request URI must either be an absolute URI or BaseAddress m
                    An invalid request URI was provided. The request URI must either be an absolute URI or BaseAddress must be set报错处理
				An invalid request URI was provided. The request URI must either be an absolute URI or BaseAddress m