qrcodeService/QRCodeService/Controllers/ImageController.cs

using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using QRCoder;
using System.IO;
using QRCodeService.Application.Queries;
using QRCodeService.Models;

namespace QRCodeService.Controllers
{
    [Route("api/[controller]")]
    [ApiController]
    public class ImageController : ControllerBase
    {
        readonly ILinkQueries linkQueries;
        readonly IAppQueries appQueries;

        public ImageController(ILinkQueries linkQueries, IAppQueries appQueries)
        {
            this.linkQueries = linkQueries;
            this.appQueries = appQueries;
        }

        [Route("qrcode")]
        [HttpPost]
        public async Task<IActionResult> GetImage(GetQRCodeModel input)
        {
            var app = await appQueries.GetAppAsync(input.AppId);
            if (app == null)
            {
                return BadRequest();
            }
            if (!await input.CheckValidAsync(app.Appkey))
            {
                return BadRequest();
            }
            var link = await linkQueries.GetLinkAsync(input.ShortCode);
            if (link.AppId != input.AppId)
            {
                return BadRequest();
            }
            var qrCodeGenerator = new QRCodeGenerator();
            var data = qrCodeGenerator.CreateQrCode($"http://localhost:5000/{link.ShortCode}", QRCodeGenerator.ECCLevel.Q);
            var qrCode = new QRCode(data);
            using (var stream = new MemoryStream())
            {
                qrCode.GetGraphic(20).Save(stream, System.Drawing.Imaging.ImageFormat.Png);
                return File(stream.ToArray(), "image/png");
            }
        }
    }
}