Asp.NetCore3.1 asp.net 5.0 中多次读取 Request.Body Ajax Post过来的JSON数据等已验证有效

Posted on 2020-06-13 02:26 WebEnh 阅读(598) 评论(0) 编辑收藏举报

首先，以下方式是错误的（这个重复读取只能在using语句里面生效，因为用了ms对象赋值，当using结束后ms资源被释放，Request.Body就无法再读了）

[HttpPost]
public async Task<string> Post()
{
 
    //StreamReader sr = new StreamReader(Request.Body);
    //string data = await sr.ReadToEndAsync();
 
    string data = "";
    using (MemoryStream ms = new MemoryStream())
    {
        await Request.Body.CopyToAsync(ms);
        //设置当前流的位置为0
        ms.Seek(0, SeekOrigin.Begin);
        logger.LogInformation("ms.Length=" + ms.Length);
        //这里ReadToEnd执行完毕后requestBodyStream流的位置会从0到最后位置(即request.ContentLength)
        data = new StreamReader(ms, Encoding.UTF8).ReadToEnd();
        logger.LogInformation("data=" + data);
 
        //设置当前流的位置为0
        ms.Seek(0, SeekOrigin.Begin);
        Request.Body = ms;
        StreamReader sr = new StreamReader(Request.Body);
        string data2 = await sr.ReadToEndAsync();
        logger.LogInformation("data2=" + data2);
    }
 
    string header = $"请求头:\r\n";
    foreach (var item in Request.Headers)
    {
        header += $"{item.Key}:{item.Value}\r\n";
    }
    logger.LogInformation(header);
 
    var ip = Request.Headers["X-Forwarded-For"].FirstOrDefault();
    if (string.IsNullOrEmpty(ip))
    {
        //ip = Request.HttpContext.Connection.RemoteIpAddress.ToString();
        //ip = Request.HttpContext.Connection.LocalIpAddress.MapToIPv4().ToString();
        ip = Request.HttpContext.Connection.RemoteIpAddress.MapToIPv4().ToString();
    }
    logger.LogInformation("ip=" + ip);
 
    //...
}


正确方式是：

        [HttpPost]
        public async Task<string> Post()
        {
            //StreamReader sr = new StreamReader(Request.Body);
            //string data = await sr.ReadToEndAsync();

            string data = "";

            //Request.EnableBuffering();可以实现多次读取Body
            Request.EnableBuffering();
            StreamReader sr = new StreamReader(Request.Body);
            data = await sr.ReadToEndAsync();
            logger.LogInformation("data=" + data);
            Request.Body.Seek(0, SeekOrigin.Begin);

            //再次读取 依然可以成功读到
            Request.EnableBuffering();
            StreamReader sr2 = new StreamReader(Request.Body);
            string data2 = await sr2.ReadToEndAsync();
            logger.LogInformation("data2=" + data2);
            Request.Body.Seek(0, SeekOrigin.Begin);
            

            string header = $"请求头:\r\n";
            foreach (var item in Request.Headers)
            {
                header += $"{item.Key}:{item.Value}\r\n";
            }
            logger.LogInformation(header);

            var ip = Request.Headers["X-Forwarded-For"].FirstOrDefault();
            if (string.IsNullOrEmpty(ip))
            {
                //ip = Request.HttpContext.Connection.RemoteIpAddress.ToString();
                //ip = Request.HttpContext.Connection.LocalIpAddress.MapToIPv4().ToString();
                ip = Request.HttpContext.Connection.RemoteIpAddress.MapToIPv4().ToString();
            }
            logger.LogInformation("ip=" + ip);

            //...
        }