c#WinForm验证码

cs:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace GDI_绘图
{
    public partial class Form3 : Form
    {
        public Form3()
        {
            InitializeComponent();
        }
        string code;
        Random r = new Random();
            //加载事件
        private void Form3_Load(object sender, EventArgs e)
        {
            setCode(4);//验证码四个长度
        }

        private void setCode(int length)
        {
            code = "";
            for (int i = 0; i < length; i++)
            {
                int type = r.Next(0,2);//存在两次
                if (type==0)
                {
                    code += r.Next(0, 9);
                }
                else if (type==1)
                {
                    code += (char)r.Next(97,123);
                }
            }
            if (string.IsNullOrWhiteSpace(code))
            {
                return;
            }
            Bitmap img = new Bitmap(code.Length*20+10,30);
            Graphics graphics = Graphics.FromImage(img);
            graphics.Clear(Color.White);
            Pen pen = new Pen(Color.Black,1);
            graphics.DrawRectangle(pen,0,0,img.Width-1,img.Height-1);
            for (int i = 0; i < code.Length; i++)
            {
                Pen p = new Pen(Color.FromArgb(r.Next(255),r.Next(255),r.Next(255)),r.Next(1,2));//画线
                graphics.DrawLine(p,r.Next(0,img.Width),r.Next (0,img.Height),r.Next (img.Width),r.Next(0,img.Height));//线段的两个点
            }
            graphics.DrawString(code, new Font("宋体",15,FontStyle.Italic|FontStyle.Bold),new SolidBrush(Color.FromArgb(r.Next(255), r.Next(255), r.Next(255))),new Point(5,5));
            for (int i = 0; i < code.Length*20; i++)
            {
                graphics.FillEllipse(new SolidBrush(Color.FromArgb(r.Next(255), r.Next(255), r.Next(255))),r.Next(0,img.Width),r.Next(0,img.Height),2,2);//绘制小圆点
            }
            pictureBox1.Image = img;
        }


        //确认
        private void button1_Click(object sender, EventArgs e)
        {
            if (code.ToUpper().Equals(textBox1.Text.ToUpper()))
            {
                MessageBox.Show("正确");
            }
            else
            {
                MessageBox.Show("请重新输入");
                setCode(4);
            }
        }

        private void pictureBox1_Click(object sender, EventArgs e)
        {
            setCode(4);
        }
    }
}

绘制字母数字圆点线条；利用picbox装起来；

来源：CSDN

作者：方丈山

链接：https://blog.csdn.net/qq_44820230/article/details/103757246