In this tutorial, we are going to discuss single and multiple file uploads with the help of the IFormFile Interface and others which are provided by .NET and step-by-step implementation using .NET Core 6 Web API.
Prerequisites
- .NET Core 6 SDK
- Visual Studio 2022
- SQL Server
- Postman
How to Implement
1. Create a new .NET Core Web API
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2. Install following NuGet Packages
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3. Create this following file entities
FileDetails.cs
using System.ComponentModel.DataAnnotations;
using System.ComponentModel.DataAnnotations.Schema;
namespace FileUpload.Entities
{
[Table("FileDetails")]
public class FileDetails
{
[Key]
[DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public int ID { get; set; }
public string FileName { get; set; }
public byte[] FileData { get; set; }
public FileType FileType { get; set; }
}
}
FileUploadModel
namespace FileUpload.Entities
{
public class FileUploadModel
{
public IFormFile FileDetails { get; set; }
public FileType FileType { get; set; }
}
}
FileType
namespace FileUpload.Entities
{
public enum FileType
{
PDF = 1,
DOCX = 2
}
}
4. Check your DbContextClass.cs class
using FileUpload.Entities;
using Microsoft.EntityFrameworkCore;
namespace FileUpload.Data
{
public class DbContextClass : DbContext
{
protected readonly IConfiguration Configuration;
public DbContextClass(IConfiguration configuration)
{
Configuration = configuration;
}
protected override void OnConfiguring(DbContextOptionsBuilder options)
{
options.UseSqlServer(Configuration.GetConnectionString("DefaultConnection"));
}
public DbSet<FileDetails> FileDetails { get; set; }
}
}
5. Create IFileService and FileService files
IFileService
using FileUpload.Entities;
namespace FileUpload.Services
{
public interface IFileService
{
public Task PostFileAsync(IFormFile fileData, FileType fileType);
public Task PostMultiFileAsync(List<FileUploadModel> fileData);
public Task DownloadFileById(int fileName);
}
}
FileService
using FileUpload.Data;
using FileUpload.Entities;
using Microsoft.EntityFrameworkCore;
namespace FileUpload.Services
{
public class FileService : IFileService
{
private readonly DbContextClass dbContextClass;
public FileService(DbContextClass dbContextClass)
{
this.dbContextClass = dbContextClass;
}
public async Task PostFileAsync(IFormFile fileData, FileType fileType)
{
try
{
var fileDetails = new FileDetails()
{
ID = 0,
FileName = fileData.FileName,
FileType = fileType,
};
using (var stream = new MemoryStream())
{
fileData.CopyTo(stream);
fileDetails.FileData = stream.ToArray();
}
var result = dbContextClass.FileDetails.Add(fileDetails);
await dbContextClass.SaveChangesAsync();
}
catch (Exception)
{
throw;
}
}
public async Task PostMultiFileAsync(List<FileUploadModel> fileData)
{
try
{
foreach(FileUploadModel file in fileData)
{
var fileDetails = new FileDetails()
{
ID = 0,
FileName = file.FileDetails.FileName,
FileType = file.FileType,
};
using (var stream = new MemoryStream())
{
file.FileDetails.CopyTo(stream);
fileDetails.FileData = stream.ToArray();
}
var result = dbContextClass.FileDetails.Add(fileDetails);
}
await dbContextClass.SaveChangesAsync();
}
catch (Exception)
{
throw;
}
}
public async Task DownloadFileById(int Id)
{
try
{
var file = dbContextClass.FileDetails.Where(x => x.ID == Id).FirstOrDefaultAsync();
var content = new System.IO.MemoryStream(file.Result.FileData);
var path = Path.Combine(
Directory.GetCurrentDirectory(), "FileDownloaded",
file.Result.FileName);
await CopyStream(content, path);
}
catch (Exception)
{
throw;
}
}
public async Task CopyStream(Stream stream, string downloadPath)
{
using (var fileStream = new FileStream(downloadPath, FileMode.Create, FileAccess.Write))
{
await stream.CopyToAsync(fileStream);
}
}
}
}
7. Configure a few services in Program Class and inside DI container
using FileUpload.Data;
using FileUpload.Services;
var builder = WebApplication.CreateBuilder(args);
// Add services to the container.
builder.Services.AddControllers();
// Learn more about configuring Swagger/OpenAPI at https://aka.ms/aspnetcore/swashbuckle
builder.Services.AddEndpointsApiExplorer();
builder.Services.AddSwaggerGen();
builder.Services.AddDbContext<DbContextClass>();
builder.Services.AddScoped<IFileService, FileService>();
var app = builder.Build();
// Configure the HTTP request pipeline.
if (app.Environment.IsDevelopment())
{
app.UseSwagger();
app.UseSwaggerUI();
}
app.UseAuthorization();
app.MapControllers();
app.Run();
8. Create a new database inside SQL server and named it as FileUploadDemo
9. Create FileDetails table using script below
USE [FileUploadDemo]
GO
/****** Object: Table [dbo].[FileDetails] Script Date: 10/1/2022 5:51:22 PM ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE TABLE [dbo].[FileDetails](
[ID] [int] IDENTITY(1,1) NOT NULL,
[FileName] [nvarchar](80) NOT NULL,
[FileData] [varbinary](max) NOT NULL,
[FileType] [int] NULL,
CONSTRAINT [PK_FileDetails] PRIMARY KEY CLUSTERED
(
[ID] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON, OPTIMIZE_FOR_SEQUENTIAL_KEY = OFF) ON [PRIMARY]
) ON [PRIMARY] TEXTIMAGE_ON [PRIMARY]
GO
10. Put database connection inside the appsettings.json file
{
"Logging": {
"LogLevel": {
"Default": "Information",
"Microsoft.AspNetCore": "Warning"
}
},
"AllowedHosts": "*",
"ConnectionStrings": {
"DefaultConnection": "Data Source=DESKTOP-****;;Initial Catalog=FileUploadDemo;User Id=sa;Password=database;"
}
}
11. Run the application
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12. Upload a single file using Swagger
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13. Use Postman to upload multiple files. Here you can see we use array index to send the file and their type and it will be working fine.
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14. Download files on local system at a specified path location
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15. You can see your downloaded file
Also, in the database, we can see whatever files we already uploaded using the above endpoints
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Conclusion
In this article, we discussed the single and multiple file upload using IFormFile and step-by-step implementation of that using .NET Core Web API and also read and save the files from the database to the specified location.
Happy Coding!