using System;
using System.Drawing;
using System.Drawing.Imaging;
using System.IO;
using System.Text;

public class CaptchaHelper
{
    public (string key, string base64) GenerateCaptcha()
    {
        string key = Guid.NewGuid().ToString("N"); // 生成一个唯一的Key
        string captchaText = GenerateRandomCode(4); // 生成一个4位随机验证码

        Bitmap bitmap = new Bitmap(100, 30);
        Graphics graphic = Graphics.FromImage(bitmap);

        try
        {
            var rnd = new Random();
            // 设置验证码的字体、颜色等属性
            Random random = new Random();
            Font font = new Font("Arial", 15, FontStyle.Bold);
            Brush brush = new SolidBrush(Color.FromArgb(rnd.Next(0, 256), rnd.Next(0, 256), rnd.Next(0, 256), rnd.Next(0, 256)));
            PointF point = new PointF(5, 5);
            
            // 绘制验证码
            graphic.Clear(Color.White);
            graphic.DrawString(captchaText, font, brush, point);

            // 将图片转换为Base64字符串
            using (MemoryStream memoryStream = new MemoryStream())
            {
                bitmap.Save(memoryStream, ImageFormat.Png);
                byte[] imageBytes = memoryStream.ToArray();

                string base64String = Convert.ToBase64String(imageBytes);
                return (key, base64String);
            }
        }
        finally
        {
            graphic.Dispose();
            bitmap.Dispose();
        }
    }

    private string GenerateRandomCode(int length)
    {
        const string randomCode = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
        Random random = new Random();
        StringBuilder sb = new StringBuilder();

        for (int i = 0; i < length; i++)
        {
            sb.Append(randomCode[random.Next(randomCode.Length)]);
        }

        return sb.ToString();
    }
}

[HttpGet]
public async Task<IActionResult> Captcha()
{
    (string key, string base64)  =new CaptchaHelper().GenerateCaptcha();
    return Ok(new
    {
        code,
        data =
        new
        {
            captchaKey = key,
            captchaBase64 = "data:image/png;base64,"+ base64
        }
    });
}

/** 获取验证码 */
function getCaptcha() {
  AuthAPI.getCaptcha().then((data) => {
    loginData.value.captchaKey = data.captchaKey;
    captchaBase64.value = data.captchaBase64;
  });
}

<el-image
              @click="getCaptcha"
              :src="captchaBase64"
              class="captcha-image"
            />

• 本文标题： Vue3+NETAPI实现验证码 captchaKey,captchaBase64
• 文章分类：【.NET/Web】
• 非特殊说明，本文版权归【胡同里的砖头】个人博客 所有，转载请注明出处.

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