C# mvc 編寫圖片驗證碼

---------------------------------------------------------------------------這是一個helper 封裝類裏可以直接調用
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Drawing;

namespace WebApplication8.Models
{
public class VerificationCodeHelper
{
private static Color BackColor = Color.White;
private static int Width = 62;
private static int Height = 21;
private Random _random;
// private string _code;

    private int _brushNameIndex;

    public byte[] GetVCode(string codeStr)
    {
        _random = new Random();
        using (Bitmap img = new Bitmap(Width, Height))
        {
            // _code = GetRandomCode();
            // System.Web.HttpContext.Current.Session["vcode"] = _code;
            using (Graphics g = Graphics.FromImage(img))
            {
                g.Clear(Color.White);//繪畫背景顏色

                Paint_Text(g, codeStr);// 繪畫文字
                // g.DrawString(strCode, new Font("微軟雅黑", 15), Brushes.Blue, new PointF(5, 2));// 繪畫文字
                Paint_TextStain(img);// 繪畫噪音點
                g.DrawRectangle(Pens.DarkGray, 0, 0, Width - 1, Height - 1);//繪畫邊框
                using (System.IO.MemoryStream ms = new System.IO.MemoryStream())
                {
                    //將圖片 保存到內存流中
                    img.Save(ms, System.Drawing.Imaging.ImageFormat.Gif);
                    //將內存流 裏的 數據  轉成 byte 數組 返回
                    return ms.ToArray();
                }
            }
        }

    }

    /// <summary>
    /// 繪畫文字
    /// </summary>
    /// <param name="g"></param>
    private void Paint_Text(Graphics g, string code)
    {
        g.DrawString(code, GetFont(), GetBrush(), 3, 1);
    }

    /// <summary>
    /// 繪畫文字噪音點
    /// </summary>
    /// <param name="g"></param>
    private void Paint_TextStain(Bitmap b)
    {
        string[] BrushName = new string[] {    "OliveDrab",
                                              "ForestGreen",
                                              "DarkCyan",
                                              "LightSlateGray",
                                              "RoyalBlue",
                                              "SlateBlue",
                                              "DarkViolet",
                                              "MediumVioletRed",
                                              "IndianRed",
                                              "Firebrick",
                                              "Chocolate",
                                              "Peru",
                                              " enrod"
                                         };

        for (int n = 0; n < 30; n++)
        {
            int x = _random.Next(Width);
            int y = _random.Next(Height);
            b.SetPixel(x, y, Color.FromName(BrushName[_brushNameIndex]));

        }

    }
    /// <summary>
    /// 隨機取一個字體
    /// </summary>
    /// <returns></returns>
    private Font GetFont()
    {
        string[] FontItems = new string[]{   "Arial",
                                              "Helvetica",
                                              "Geneva",
                                              "sans-serif",
                                              "Verdana"
                                          };

        int fontIndex = _random.Next(0, FontItems.Length);
        FontStyle fontStyle = GetFontStyle(_random.Next(0, 2));
        return new Font(FontItems[fontIndex], 12, fontStyle);
    }
    /**/
    /**/
    /**/
    /// <summary>
    /// 隨機取一個筆刷
    /// </summary>
    /// <returns></returns>
    private Brush GetBrush()
    {
        Brush[] BrushItems = new Brush[]{     Brushes.OliveDrab,
                                              Brushes.ForestGreen,
                                              Brushes.DarkCyan,
                                              Brushes.LightSlateGray,
                                              Brushes.RoyalBlue,
                                              Brushes.SlateBlue,
                                              Brushes.DarkViolet,
                                              Brushes.MediumVioletRed,
                                              Brushes.IndianRed,
                                              Brushes.Firebrick,
                                              Brushes.Chocolate,
                                              Brushes.Peru,
                                              Brushes.Goldenrod
                                        };

        int brushIndex = _random.Next(0, BrushItems.Length);
        _brushNameIndex = brushIndex;
        return BrushItems[brushIndex];
    }
    /// <summary>
    /// 繪畫背景顏色
    /// </summary>
    /// <param name="g"></param>
    private void Paint_Background(Graphics g)
    {
        g.Clear(BackColor);
    }
    /**/
    /**/
    /**/
    /// <summary>
    /// 取一個字體的樣式
    /// </summary>
    /// <param name="index"></param>
    /// <returns></returns>
    private FontStyle GetFontStyle(int index)
    {
        switch (index)
        {
            case 0:
                return FontStyle.Bold;
            case 1:
                return FontStyle.Italic;
            default:
                return FontStyle.Regular;
        }
    }

    /// <summary>
    /// 取得一個 4 位的隨機碼
    /// </summary>
    /// <returns></returns>
    public string GetRandomCode()
    {
        return Guid.NewGuid().ToString().Substring(0, 5);
    }
}

}
---------------------------------------------------------------------------------------------------到這裏


希望能對大家有幫助 這只是最基本的圖片驗證代碼
如果有幫助記得點贊哦！！！