关于MVC4.0 WebAPI上传图片重命名以及图文结合

MVC4.0 WebAPI上传后的图片默认以字符串bodypart结合Guid来命名，且没有文件后缀，为解决上传图片重命名以及图文结合发布的问题，在实体对象的处理上，可将图片属性定义为byte[]对象，至于图片的重命名，通过重写继承MultipartFormDataStreamProvider类来解决！

参照API的官方文档，上传文件代码大致如下：

public class FileUploadController : ApiController
{

public Task<HttpResponseMessage> PostFile()
        {
            HttpRequestMessage request = this.Request;         

            string root = System.Web.HttpContext.Current.Server.MapPath("~/App_Data/uploads");
            //var provider = new MultipartFormDataStreamProvider(root);//原写法
            var provider = new RenamingMultipartFormDataStreamProvider(root);//重命名写法
            //provider.BodyPartFileNames.sel(kv => kv.Value)
            var task = request.Content.ReadAsMultipartAsync(provider).
                ContinueWith<HttpResponseMessage>(o =>
                {
                    string file1 = provider.BodyPartFileNames.First().Value;//多张图片循环provider.BodyPartFileNames或provider.FileData
　　　　　　　　　　　 //string file1 = provider.GetLocalFileName(provider.FileData[0].Headers);//返回重写的文件名（注意，由于packages包版本的不同，用BodyPartFileNames还是FileData需要留意）
                    // this is the file name on the server where the file was saved                     

                    return new HttpResponseMessage()
                    {
                        Content = new StringContent("File uploaded." + file1)
                    };
                }
            );
            return task;
        }
}

 

再来看看继承MultipartFormDataStreamProvider的类:

public class RenamingMultipartFormDataStreamProvider : MultipartFormDataStreamProvider
    {
        public string Root { get; set; }
        //public Func<FileUpload.PostedFile, string> OnGetLocalFileName { get; set; }

        public RenamingMultipartFormDataStreamProvider(string root)
            : base(root)
        {
            Root = root;
        }

        public override string GetLocalFileName(HttpContentHeaders headers)
        {
            string filePath = headers.ContentDisposition.FileName;

            // Multipart requests with the file name seem to always include quotes.
            if (filePath.StartsWith(@"""") && filePath.EndsWith(@""""))
                filePath = filePath.Substring(1, filePath.Length - 2);

            var filename = Path.GetFileName(filePath);
            var extension = Path.GetExtension(filePath);
            var contentType = headers.ContentType.MediaType;

            return filename;         
        }        

    }

该方法通过直接指定form的action为请求的WebAPI上传地址来处理；如：

<form name="form1" method="post" enctype="multipart/form-data" action="http://localhost:8000/api/FileUpload/PostFile">。

另外我们还可以通过向WebAPI提交byte[]形式的文件来解决(以HttpClient方式向WebAPI地址提交上传对象)，首先定义文件上传类，以最简单的为例：

相关上传实体类：

View Code

上传的Action方法：

View Code

 

WebAPI接收端，主要方法如下（Controller代码略）：

View Code

 

 Httpclient相关扩展方法如下：

+ View Code

　　简单调用示例如下：

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19

UploadFileEntity entity = new UploadFileEntity(); entity.FileName = DateTime.Now.ToString("yyyyMMddHHmmssffff") + fileExt;//自定义文件名称，这里以当前时间为例 entity.FileData = GetByte(Request.Files[0].InputStream); var request = JsonConvert.SerializeObject(entity); HttpContent httpContent = new StringContent(request); httpContent.Headers.ContentType = new MediaTypeHeaderValue("application/json"); var httpClient = new HttpClient(); httpClient.PostAsync("http://localhost:7901/api/FileUpload/SaveFile", httpContent); public static byte[] GetByte(Stream stream)         {             byte[] fileData = new byte[stream.Length];             stream.Read(fileData, 0, fileData.Length);             stream.Close();             return fileData;         }