public class InputOutputAlterMiddleware
    {
        private readonly RequestDelegate _next;
        private readonly ILogger _logger;

        public InputOutputAlterMiddleware(RequestDelegate next, ILoggerFactory loggerFactory)
        {
            _next = next;
            _logger = loggerFactory.CreateLogger<InputOutputAlterMiddleware>();
        }

        
 
public async Task InvokeAsync(HttpContext context)
        {
            var method = context.Request.Method;
            if (method.Equals("POST")|| method.Equals("GET"))
            {
                var dic = new Dictionary<string, StringValues>();
                foreach (var item in context.Request.Query.Keys)
                {
                    dic.Add(item, 
 
new StringValues(context.Request.Query[item].ToString()));
                }
                dic.Add("newbarcode", new StringValues("123456"));
                dic.Remove("barcode");
                //修改提交過來的值
                context.Request.Form = new FormCollection(dic);
                using (var ms = new
 
 MemoryStream())
                {
                    var orgBodyStream = context.Response.Body;
                    context.Response.Body = ms;
                    context.Response.ContentType = "multipart/form-data";
                    await _next(context);

                    //using (var sr = new StreamReader(ms))
                    //{
                    //    ms.Seek(0, SeekOrigin.Begin);
                    //    //得到Action的返回值
                    //    var responseJsonResult = sr.ReadToEnd();
                    //    ms.Seek(0, SeekOrigin.Begin);
                    //    //如下程式碼若不註釋則會顯示Action的返回值 這裡做了註釋 則清空Action傳過來的值  
                    //    //  await ms.CopyToAsync(orgBodyStream);
                    //    var alterResult = $"沒事返回值【{responseJsonResult}】被我改過來啦！";

                    //    context.Response.Body = orgBodyStream;
                    //    //顯示修改後的資料 
                    //    await context.Response.WriteAsync(alterResult, Encoding.UTF8);

                    //}
                }

            }
            else
            {
                await _next(context);
            }

        }
    }

    public static class InputOutputAlterMiddlewareExtensions
    {
        public static IApplicationBuilder UseInputOutputAlter(
           this IApplicationBuilder builder)
        {
            return builder.UseMiddleware<InputOutputAlterMiddleware>();
        }
    }

        public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
        {
            app.UseInputOutputAlter();
}