前段时间，一直有练习ASP.NET MVC与Web API交互，接下来，Insus.NET再做一些相关的练习，Web API与文件操作，如POST文件至Web API，更新或是删除等。
不管怎样，先在数据库创建一张表，用来存储上传的文件。本实例中是把文件存储过数据库的。
CREATE TABLE ApiFileDemo( [Afd_nbr] INT IDENTITY(1,1) PRIMARY KEY NOT NULL, [Picture] [image] NULL, [PictureType] [nvarchar](30) NULL, [FileExtension] [nvarchar](10) NULL)GOCREATE PROCEDURE [dbo].[usp_ApiFileDemo_Insert]( @Picture IMAGE, @PictureType NVARCHAR(30), @FileExtension NVARCHAR(10))ASINSERT INTO [dbo].[ApiFileDemo] ([Picture],[PictureType],[FileExtension]) VALUES (@Picture,@PictureType,@FileExtension)GOCREATE PROCEDURE [dbo].[usp_ApiFileDemo_Update]( @Afd_nbr INT, @Picture IMAGE, @PictureType NVARCHAR(30), @FileExtension NVARCHAR(10))ASUPDATE [dbo].[ApiFileDemo] SET [Picture] = @Picture,[PictureType] = @PictureType,[FileExtension] = @FileExtension WHERE [Afd_nbr] = @Afd_nbrGOCREATE PROCEDURE [dbo].[usp_ApiFileDemo_Delte]( @Afd_nbr INT)ASDELETE FROM [dbo].[ApiFileDemo] WHERE [Afd_nbr] = @Afd_nbrGO
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写到这里，发现少了一个存储过程，就是获取某一张图片的：
CREATE PROCEDURE [dbo].[usp_ApiFileDemo_GetByPrimarykey]( @Afd_nbr INT)ASSELECT [Afd_nbr],[Picture],[PictureType],[FileExtension] FROM [dbo].[ApiFileDemo] WHERE [Afd_nbr] = @Afd_nbrGO
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接下来，我们可以设计Web API接口，待完成了，发布至网上，其它客户端就可以操作了。
根据数据库表，可以在API项目中，创建Model:
using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Threading.Tasks;namespace Insus.NET.Models{ public class File { public int Afd_nbr { get; set; } public byte[] Picture { get; set; } public string PictureType { get; set; } public string FileExtension { get; set; } }}Source Code
写好model之后，还需要为API写一个实体，这个对象只是让程序与数据库进行交互。获取与存储等操作：
using Insus.NET.DataBases;using Insus.NET.Models;using System;using System.Collections.Generic;using System.Data;using System.Linq;using System.Text;using System.Threading.Tasks;using Insus.NET;namespace Insus.NET.Entities{ public class FileEntity { BizSP sp = new BizSP(); public DataTable GetFileByPrimarykey(File f) { List<Parameter> param = new List<Parameter>() { new Parameter("@Afd_nbr", SqlDbType.Int,4,f.Afd_nbr) }; sp.ConnectionString = DB.ConnectionString; sp.Parameters = param; sp.ProcedureName = "usp_ApiFileDemo_GetByPrimarykey"; return sp.ExecuteDataSet().Tables[0]; } public void Insert(File f) { List<Parameter> param = new List<Parameter>() { new Parameter("@Picture", SqlDbType.Image,-1,f.Picture), new Parameter("@PictureType",SqlDbType.NVarChar,-1,f.PictureType), new Parameter("@FileExtension",SqlDbType.NVarChar,-1,f.FileExtension) }; sp.ConnectionString = DB.ConnectionString; sp.Parameters = param; sp.ProcedureName = "usp_ApiFileDemo_Insert"; sp.Execute(); } public void Update(File f) { List<Parameter> param = new List<Parameter>() { new Parameter("@Afd_nbr", SqlDbType.Int,4,f.Afd_nbr), new Parameter("@Picture", SqlDbType.Image,-1,f.Picture), new Parameter("@PictureType",SqlDbType.NVarChar,-1,f.PictureType), new Parameter("@FileExtension",SqlDbType.NVarChar,-1,f.FileExtension) }; sp.ConnectionString = DB.ConnectionString; sp.Parameters = param; sp.ProcedureName = "usp_ApiFileDemo_Update"; sp.Execute(); } public void Delete(File f) { List<Parameter> param = new List<Parameter>() { new Parameter("@Afd_nbr", SqlDbType.Int,4,f.Afd_nbr) }; sp.ConnectionString = DB.ConnectionString; sp.Parameters = param; sp.ProcedureName = "usp_ApiFileDemo_Delte"; sp.Execute(); } }}Source Code
下面的控制器FileController，即是为客户端访问的接口，这个类别，它是继承了ApiController。
using Insus.NET.Entities;using Insus.NET.ExtendMethods;using Insus.NET.Models;using System;using System.Collections.Generic;using System.Linq;using System.Net;using System.Net.Http;using System.Web.Http;namespace Insus.NET.Controllers{ public class FileController : ApiController { // GET: File FileEntity fe = new FileEntity(); // GET: ApiFileDemo [HttpGet] public string Get(int id) { File f = new File(); f.Afd_nbr = id; return fe.GetFileByPrimarykey(f).ToJson(); } [HttpPost] public void Post(File f) { fe.Insert(f); } [HttpPut] public void Put(File f) { fe.Update(f); } [HttpDelete] public void Delete(File f) { fe.Delete(f); } [HttpDelete] public void Delete(int id) { File f = new File(); f.Afd_nbr = id; fe.Delete(f); } }}Source Code
Web API完成，我们需要把它发布至IIS中去，如何发布，可以参考《创建与使用Web API》http://www.cnblogs.com/insus/p/5019088.html......
Ok，接下来，我们开发客户端的程序，尝试上Web API上传一些文件。
在客户端的项目中，创建一个mode:
using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Threading.Tasks;namespace Insus.NET.Models{ public class File { public int Afd_nbr { get; set; } public byte[] Picture { get; set; } public string PictureType { get; set; } public string FileExtension { get; set; } }}Source Code
ASP.NET MVC的控制器中，创建2个Action:
public ActionResult Upload() { return View(); } [HttpPost] public ActionResult Upload(IEnumerable<HttpPostedFileBase> files) { foreach (var file in files) { if (file.ContentLength > 0) { Insus.NET.Models.File f = new Insus.NET.Models.File(); f.PictureType = file.ContentType; string fn = Path.GetFileName(file.FileName); f.FileExtension = fn.Substring(fn.LastIndexOf('.')); using (Stream inputStream = file.InputStream) { MemoryStream memoryStream = inputStream as MemoryStream; if (memoryStream == null) { memoryStream = new MemoryStream(); inputStream.CopyTo(memoryStream); } f.Picture = memoryStream.ToArray(); } HttpClient client = new HttpClient(); string ff = f.ToJson(); HttpContent httpcontent = new StringContent(ff, System.Text.Encoding.UTF8, "application/json"); client.PostAsync("http://localhost:9001/api/file", httpcontent) .ContinueWith((postTask) => { postTask.Result.EnsureSuccessStatusCode(); }); } } return RedirectToAction("Upload"); }Source Code
在视图中，可以这样做：
程序运行：
图片上传成功之后，现在我们需要把图片显示出来。
由于存储的是二进制的数据流，显示图片时，需要处理一下，需要写一个自定义的Result，如：PictureResult，它需要继承ContentResult：
using System;using System.Collections.Generic;using System.IO;using System.Linq;using System.Text;using System.Threading.Tasks;using System.Web;using System.Web.Mvc;namespace Insus.NET.Results{ public class PictureResult : ContentResult { public byte[] _Picture { get; set; } public string _PictureType { get; set; } public PictureResult(byte[] sourceStream, String contentType) { _Picture = sourceStream; _PictureType = contentType; } public override void ExecuteResult(ControllerContext context) { var response = context.HttpContext.Response; response.Clear(); response.Cache.SetCacheability(HttpCacheability.NoCache); response.ContentType = ContentType; if (_Picture != null) { var stream = new MemoryStream(_Picture); stream.WriteTo(response.OutputStream); stream.Dispose(); } } }}Source Code
接下来，我们在控制器创建视图的Action:
public ActionResult ShowPhoto() { return View(); } public ActionResult ShowPicture(int id) { var files = ApiUtility.Get<Insus.NET.Models.File>("http://localhost:9001/api/file/" + id); var model = files.FirstOrDefault(); PictureResult pictureResult = new PictureResult(model.Picture, model.PictureType); return pictureResult; }Source Code
客户端程序运行，可以看到图片显示的效果：
在Web API的接口还有更新，删除的接口，看官们可以继续完成。方法在Insus.NET博客上也有相似或是相关的功能......
随时随地看视频
