ASP.NET Core重复读取Request.Body

//HttpContext
context.Request.EnableRewind(); //创建缓冲区存放Request.Body的内容，从而允许反复读取Request.Body的Stream
using (var ms=new MemoryStream())
{
    context.Request.Body.Position = 0;  //请求到控制器之后 Position重置0
    context.Request.Body.CopyTo(ms);
    context.Request.Body.Position = 0;
    using (var st = new StreamReader(ms))
    {
        st.BaseStream.Position = 0;
        body = st.ReadToEnd().Replace("\n", "");
    }
}