WebApi 后端代码与文件上传实现详细指南

1. WebApi 后端代码

1.1 文件上传接口实现

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Mvc.Filters;
using Microsoft.AspNetCore.Mvc;
using ZRFCoreTestMongoDB.Model;
using ZRFCoreTestMongoDB.Commoms;
using Microsoft.IdentityModel.Tokens;
using System.Text;
using System.Security.Claims;
using System.IdentityModel.Tokens.Jwt;
using Microsoft.AspNetCore.Http;
using System.IO;
using Microsoft.AspNetCore.Hosting;
[ApiController]
[Route("api/[Controller]")]
public class MyJwtTestController : ControllerBase
{
    private readonly JwtConfigModel _jsonmodel;
    private IWebHostEnvironment _evn;
    public MyJwtTestController(IWebHostEnvironment evn)
    {
        this._evn = evn;
        _jsonmodel = AppJsonHelper.InitJsonModel();
    }
    [HttpPost, Route("UpFile")]
    public async Task
   
     UpFile([FromForm] IFormCollection formcollection)
    {
        ApiResult result = new ApiResult();
        try
        {
            var files = formcollection.Files;
            if (files != null && files.Any())
            {
                var file = files[0];
                string contentType = file.ContentType;
                string fileOrginname = file.FileName; // 新建文本文档.txt 原始的文件名称
                string fileExtention = Path.GetExtension(fileOrginname); // 判断文件的格式是否正确
                string cdipath = Directory.GetCurrentDirectory();
                string fileupName = Guid.NewGuid().ToString("d") + fileExtention;
                string upfilePath = Path.Combine(cdipath + "/myupfiles/", fileupName);
                if (!System.IO.File.Exists(upfilePath))
                {
                    using (var stream = System.IO.File.Create(upfilePath))
                    {
                    }
                }
                double count = await UpLoadFileStreamHelper.UploadWriteFileAsync(file.OpenReadStream(), upfilePath);
                result.message = "上传成功！";
                result.code = StatusCode.success;
                result.data = $"上传的文件大小为:{count}MB";
            }
        }
        catch (Exception ex)
        {
            result.message = "上传异常,原因:" + ex.Message;
        }
        return result;
    }
    [HttpPost, Route("UpFile02")]
    public async Task
    
      UpFileBymodel([FromForm] UpFileModel model)
    {
        ApiResult result = new ApiResult();
        try
        {
            bool flag = await UpLoadFileStreamHelper.UploadWriteFileByModelAsync(model);
            result.code = flag ? StatusCode.success : StatusCode.fail;
            result.message = flag ? "上传成功" : "上传失败";
        }
        catch (Exception ex)
        {
            result.message = "上传异常,原因:" + ex.Message;
        }
        return result;
    }
    [HttpPost, Route("UpFile03")]
    public async Task
     
       UpFile03([FromForm] IFormFile file)
    {
        ApiResult result = new ApiResult();
        try
        {
            bool flag = await UpLoadFileStreamHelper.UploadWriteFileAsync(file);
            result.code = flag ? StatusCode.success : StatusCode.fail;
            result.message = flag ? "上传成功" : "上传失败";
        }
        catch (Exception ex)
        {
            result.message = "上传异常,原因:" + ex.Message;
        }
        return result;
    }
}

2. 自定义的 JSON 配置文件

{
  "upfileInfo": {
    "uploadFilePath": "/Myupfiles/"
  }
}

3. 读取自定义的 JSON 文件

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Caching;
namespace ZRFCoreTestMongoDB.Commoms
{
    public class AppJsonHelper
    {
        public static JwtConfigModel InitJsonModel()
        {
            string key = "key_myjsonfilekey";
            JwtConfigModel cachemodel = SystemCacheHelper.GetByCache(key);
            if (cachemodel == null)
            {
                ConfigurationBuilder builder = new ConfigurationBuilder();
                var broot = builder.AddJsonFile("./configs/zrfjwt.json").Build();
                cachemodel = broot.GetSection("jwtconfig").Get();
                SystemCacheHelper.SetCacheByFile(key, cachemodel);
            }
            return cachemodel;
        }
        public static T GetJsonModelByFilePath
   
    (string jsonName, string jsonFilePath)
        {
            if (!string.IsNullOrEmpty(jsonName))
            {
                ConfigurationBuilder builder = new ConfigurationBuilder();
                var broot = builder.AddJsonFile(jsonFilePath).Build();
                T model = broot.GetSection(jsonName).Get();
                return model;
            }
            return default;
        }
    }
}

4. 上传文件的测试帮助类

using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using System.IO;
using ZRFCoreTestMongoDB.Model;
namespace ZRFCoreTestMongoDB.Commoms
{
    public class UpLoadFileStreamHelper
    {
        const int WRITE_FILE_SIZE = 1024 * 1024 * 2;
        public static double UploadWriteFile(Stream stream, string path)
        {
            try
            {
                double writeCount = 0;
                using (FileStream fileStream = new FileStream(path, FileMode.OpenOrCreate, FileAccess.ReadWrite, FileShare.ReadWrite, WRITE_FILE_SIZE))
                {
                    Byte[] by = new byte[WRITE_FILE_SIZE];
                    int readCount = 0;
                    while ((readCount = stream.Read(by, 0, by.Length)) > 0)
                    {
                        fileStream.Write(by, 0, readCount);
                        writeCount += readCount;
                    }
                    return Math.Round((writeCount * 1.0 / (1024 * 1024)), 2);
                }
            }
            catch (Exception ex)
            {
                throw new Exception("发生异常：" + ex.Message);
            }
        }
        public static async Task
   
     UploadWriteFileAsync(Stream stream, string path)
        {
            try
            {
                double writeCount = 0;
                using (FileStream fileStream = new FileStream(path, FileMode.OpenOrCreate, FileAccess.ReadWrite, FileShare.ReadWrite, WRITE_FILE_SIZE))
                {
                    Byte[] by = new byte[WRITE_FILE_SIZE];
                    int readCount = 0;
                    while ((readCount = await stream.ReadAsync(by, 0, by.Length)) > 0)
                    {
                        await fileStream.WriteAsync(by, 0, readCount);
                        writeCount += readCount;
                    }
                }
                return Math.Round((writeCount * 1.0 / (1024 * 1024)), 2);
            }
            catch (Exception ex)
            {
                throw new Exception("发生异常：" + ex.Message);
            }
        }
        public static async Task
    
      UploadWriteFileAsync(IFormFile file, string path)
        {
            try
            {
                using (FileStream fileStream = new FileStream(path, FileMode.OpenOrCreate, FileAccess.ReadWrite, FileShare.ReadWrite, WRITE_FILE_SIZE))
                {
                    await file.CopyToAsync(fileStream);
                    return true;
                }
            }
            catch (Exception ex)
            {
                throw new Exception("发生异常：" + ex.Message);
            }
        }
        public static async Task
     
       UploadWriteFileByModelAsync(UpFileModel model)
        {
            try
            {
                var files = model.file.Files;
                if (files != null && files.Any())
                {
                    var file = files[0];
                    string contentType = file.ContentType;
                    string fileOrginname = file.FileName;
                    string fileExtention = Path.GetExtension(fileOrginname);
                    string cdipath = Directory.GetCurrentDirectory();
                    string fileupName = Guid.NewGuid().ToString("d") + fileExtention;
                    string upfilePath = Path.Combine(cdipath + "/myupfiles/", fileupName);
                    if (!System.IO.File.Exists(upfilePath))
                    {
                        using (var stream = System.IO.File.Create(upfilePath))
                        {
                        }
                    }
                    using (FileStream fileStream = new FileStream(upfilePath, FileMode.OpenOrCreate, FileAccess.ReadWrite, FileShare.ReadWrite))
                    {
                        using (Stream stream = file.OpenReadStream())
                        {
                            await stream.CopyToAsync(fileStream);
                            return true;
                        }
                    }
                }
            }
            catch (Exception ex)
            {
                throw new Exception("发生异常：" + ex.Message);
            }
            return false;
        }
    }

5. 全局大文件上传的使用

using System;
using System.Collections.Generic;
using System.Linq;
using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;
namespace CoreTestMongoDB
{
    public class Program
    {
        public static void Main(string[] args)
        {
            CreateHostBuilder(args).Build().Run();
        }
        public static IHostBuilder CreateHostBuilder(string[] args) =>
            Host.CreateDefaultBuilder(args)
                .ConfigureWebHostDefaults(webBuilder =>
                {
                    webBuilder.UseStartup(Startup.CreateDefaultBuilder);
                    webBuilder.ConfigureKestrel(c =>
                    {
                        c.Limits.MaxRequestBodySize = 1024 * 1024 * 300;
                    });
                })
                .UseServiceProviderFactory(new Autofac.Extensions.DependencyInjection.AutofacServiceProviderFactory());
    }
}