GDI简单绘图（二）- 绘制验证码

男娘i 2022-03-11 04:28 207阅读 0赞

本文主要演示GDI绘制数字验证码。

using System;
    using System.Drawing;
    using System.Windows.Forms;
    
    namespace GDIwork
    {
        public partial class Form1 : Form
        {
            public Form1()
            {
                InitializeComponent();
            }
    
            private void pictureBox1_Click(object sender, EventArgs e)
            {            
                //创建图片对象
                Bitmap bmp = new Bitmap(120, 40);
                //创建GDI对象
                Graphics graphics = Graphics.FromImage(bmp);
                //创建随机数对象
                Random random = new Random();
                string[] fonts = { "微软雅黑", "宋体", "黑体", "隶书", "仿宋" };
                Color[] colors = { Color.DarkOrange, Color.Blue, Color.Red, Color.Green, Color.Black };          
                for (int i = 0; i < 5; i++)
                {
                    int num = random.Next(0, 10);
                    Point point = new Point(i * 20, 0);
                    graphics.DrawString(num.ToString(), new Font(fonts[random.Next(0, 5)], 20, FontStyle.Bold), new SolidBrush(colors[random.Next(0, 5)]), point);
                }
                //绘制背景线
                for (int i = 0; i < 20; i++)
                {
                    Pen pen = new Pen(Brushes.Green);
                    Point p1 = new Point(random.Next(0, bmp.Width), random.Next(0, bmp.Height));
                    Point p2 = new Point(random.Next(0, bmp.Width), random.Next(0, bmp.Height));
                    graphics.DrawLine(pen, p1, p2);
                }
                //绘制背景点
                for (int i = 0; i < 500; i++)
                {
                    bmp.SetPixel(random.Next(0, bmp.Width), random.Next(0, bmp.Height), Color.Black);
                }
                //将图片放到pictureBox中
                pictureBox1.Image = bmp;
            }
        }
    }

执行结果：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2xpeWF6aGVuMjAxMQ_size_16_color_FFFFFF_t_70][]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2xpeWF6aGVuMjAxMQ_size_16_color_FFFFFF_t_70]: /images/20220311/ae086a8c99f3437e877cb1e3fffa4eeb.png