今天寫了一個介面，需要接收body中的純文字，但是純文字不能是json型別，需要是支援text/plain型別的，所以就去搜了一下，後面才知道，需要重新寫一個方法。

第一種方法：

 public class RawRequestBodyFormatter : IInputFormatter
    {
        public RawRequestBodyFormatter()
        {

        }

        public bool CanRead(InputFormatterContext context)
        {
            if (context == null) throw new ArgumentNullException("argument is Null");
            var contentType = context.HttpContext.Request.ContentType;
            if (string.IsNullOrEmpty(contentType) || contentType == "text/plain" || contentType == "application/octet-stream")
                return true;
            return false;
        }

        public async Task<InputFormatterResult> ReadAsync(InputFormatterContext context)
        {
            var request = context.HttpContext.Request;
            var contentType = context.HttpContext.Request.ContentType;
            if (string.IsNullOrEmpty(contentType) || contentType.ToLower() == "text/plain")
            {
                using (StreamReader reader = new StreamReader(request.Body, Encoding.UTF8))
                {
                    var content = await reader.ReadToEndAsync();
                    return await InputFormatterResult.SuccessAsync(content);
                }
            }
            if (contentType == "application/octet-stream")
            {
                using (StreamReader reader = new StreamReader(request.Body, Encoding.UTF8))
                {
                    using (var ms = new MemoryStream(2048))
                    {
                        await request.Body.CopyToAsync(ms);
                        var content = ms.ToArray();

                        return await InputFormatterResult.SuccessAsync(content);
                    }
                }
            }
            return await InputFormatterResult.FailureAsync();
        }
    }

　　第二種方法：

public sealed class PlainTextInputFormatter : TextInputFormatter
    {
        public override async Task<InputFormatterResult> ReadRequestBodyAsync(InputFormatterContext context, Encoding encoding)
        {
            string content;
            using(var reader = context.ReaderFactory(context.HttpContext.Request.Body, encoding))
            {
                content = await reader.ReadToEndAsync();
            }
            // 最後一步別忘了
            return await InputFormatterResult.SuccessAsync(content);
        }
    }
 

public sealed class CustInputFormatter : InputFormatter
    {
        public CustInputFormatter()
        {
            SupportedMediaTypes.Add("text/plain");
        }

        protected override bool CanReadType(Type type)
        {
            return (type == typeof(DateTime)) || (type == typeof(int));
        }

        public override async Task<InputFormatterResult> ReadRequestBodyAsync(InputFormatterContext context)
        {
            string val;
            using (var reader = context.ReaderFactory(context.HttpContext.Request.Body, Encoding.UTF8))
            {
                val = await reader.ReadToEndAsync();
            }
            InputFormatterResult result = null;
            if(context.ModelType == typeof(DateTime))
            {
                result = InputFormatterResult.Success(DateTime.Parse(val));
            }
            else
            {
                result = InputFormatterResult.Success(int.Parse(val));
            }
            return result;
        }
    }

　　以上參考：https://www.cnblogs.com/tcjiaan/p/9567371.html原文更精彩