Layui控件上传图片至C#WCF服务器_layui图片上传后端c#接口接收-优快云博客

本文介绍了使用Layui前端控件上传图片到C# WCF服务后台时遇到的问题及解决方案。由于上传请求的Content-Type为"multipart/form-data"，服务器端需要解析stream。在WCF环境中，由于HttpContext.Current可能为空，不能直接使用MultipartFormDataStreamProvider。作者找到了一种国外的解析代码，并针对中文字符引起的图片损坏问题进行了调整，确保从byte[]数据中复制出正确的图片文件。

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项目环境：
1、前端使用Layui控件进行图片上传,发送的请求为POST,Context-Type为”multipart/form-data; boundary=—-WebKitFormBoundaryA6CXcNQSGgWydFKy”
这里写图片描述

2、后端采用WCF服务，寄宿于Winform程序(怎么寄宿的不解释)

3、接口方法

[OperationContract]
[WebInvoke(UriTemplate = "WebUploadPhoto", Method = "POST", BodyStyle = WebMessageBodyStyle.Bare, ResponseFormat = WebMessageFormat.Json)]
string WebUploadPhoto(Stream pStream);

问题现象：
1、由于Context-Type为”multipart/form-data; boundary=—-WebKitFormBoundaryA6CXcNQSGgWydFKy”,而且是Layui控件固定的格式的(我没找到修改的方法)，导致服务器端接收的stream中包含有
—-WebKitFormBoundaryA6CXcNQSGgWydFKy的字样，真正的文件内容在其内，所以必须解析stream;

2、由于是WCF，导致HttpContext.Currect可能为空，所以无法使用MultipartFormDataStreamProvider来解析;

解决方法：
1、有幸找到国外大神的解析代码

using System;
using System.Collections.Generic;
using System.IO;
using System.Text;
using System.Text.RegularExpressions;

namespace SampleService
{
    public class MultipartParser
    {
        private byte[] requestData;
        public MultipartParser(Stream stream)
        {
            this.Parse(stream, Encoding.UTF8);
            ParseParameter(stream, Encoding.UTF8);
        }

        public MultipartParser(Stream stream, Encoding encoding)
        {
            this.Parse(stream, encoding);
        }

        private void Parse(Stream stream, Encoding encoding)
        {
            this.Success = false;

            // Read the stream into a byte array
            byte[] data = ToByteArray(stream);
            requestData = data;

            // Copy to a string for header parsing
            string content = encoding.GetString(data);

            // The first line should contain the delimiter
            int delimiterEndIndex = content.IndexOf("\r\n");

            if (delimiterEndIndex > -1)
            {
                string delimiter = content.Substring(0, content.IndexOf("\r\n"));

                // Look for Content-Type
                Regex re = new Regex(@"(?<=Content\-Type:)(.*?)(?=\r\n\r\n)");
                Match contentTypeMatch = re.Match(content);

                // Look for filename
                re = new Regex(@"(?<=filename\=\"")(.*?)(?=\"")");
                Match filenameMatch = re.Match(content);

                // Did we find the required values?
                if (contentTypeMatch.Success && filenameMatch.Success)
                {
                    // Set properties
                    this.ContentType = contentTypeMatch.Value.Trim();
                    this.Filename = filenameMatch.Value.Trim();

                    // Get the start & end indexes of the file contents
                    int startIndex = contentTypeMatch.Index + contentTypeMatch.Length + "\r\n\r\n".Length;

                    byte[] delimiterBytes = encoding.GetBytes("\r\n" + delimiter);
                    int endIndex = IndexOf(data, delimiterBytes, startIndex);

                    int contentLength = endIndex - startIndex;

                    // Extract the file contents from the byte array
                    byte[] fileData = new byte[contentLength];

                    Buffer.BlockCopy(data, startIndex, fileData, 0, contentLength);

                    this.FileContents = fileData;
                    this.Success = true;
                }
            }
        }

        private void ParseParameter(Stream stream, Encoding encoding)
        {
            this.Success = false;

            // Read the stream into a byte array
            byte[] data;
            if (requestData.Length == 0)
            {
                data = ToByteArray(stream);
            }
            else { data = requestData; }
            // Copy to a string for header parsing
            string content = encoding.GetString(data);

            // The first line should contain the delimiter
            int delimiterEndIndex = content.IndexOf("\r\n");

            if (delimiterEndIndex > -1)
            {