• encoding – Base64 Encode a PDF in C#? – Stack Overflow

สร้างโปรเจ็กส์แบบ ASP.NET Core Web API

เพิ่ม API Controller ชื่อ Values (Controllers/ValuesController.cs)

using Microsoft.AspNetCore.Mvc;

// For more information on enabling Web API for empty projects, visit https://go.microsoft.com/fwlink/?LinkID=397860

namespace WebApi1.Controllers
{
    [Route("[controller]")]
    [ApiController]
    public class ValuesController : ControllerBase
    {
        private readonly ILogger<ValuesController> _logger;
        private IWebHostEnvironment _env;

        public ValuesController(ILogger<ValuesController> logger
            , IWebHostEnvironment env)
        {
            _logger = logger;
            _env = env;
        }

        // GET api/<ValuesController>/5
        [HttpGet("{id}")]
        public string Get(int id)
        {
            string rootPath;
            if (!string.IsNullOrEmpty(_env.WebRootPath))
                rootPath = _env.WebRootPath;
            else
                rootPath = _env.ContentRootPath;
            _logger.LogInformation($"rootPath  = {rootPath}");


            #region Convert byte[] to Base64String
            string pdfPathIP = System.IO.Path.Combine(rootPath, "resource/testIP.pdf");
            _logger.LogInformation($"pdfPathIP = {pdfPathIP}");
            byte[] bytesIP = System.IO.File.ReadAllBytes(pdfPathIP);
            string pdfBase64 = Convert.ToBase64String(bytesIP);
            #endregion


            #region Convert Base64String to byte[]
            string pdfPathOP = System.IO.Path.Combine(rootPath, "resource/testOP.pdf");
            _logger.LogInformation($"pdfPathOP = {pdfPathOP}");
            byte[] bytesOP = Convert.FromBase64String(pdfBase64);
            System.IO.File.WriteAllBytes(pdfPathOP, bytesOP);
            #endregion

            return pdfBase64;
        }
    }
}

วางไฟล์ทดสอบไว้ที่ resource/testIP.pdf

ทดลองเรียก https://localhost:7034/values/5

จะได้ไฟล์ resource/testOP.pdf