stringutil.cs

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using System;
using System.Collections;
using System.ComponentModel;
using System.Drawing;
using System.Web;
using System.Web.SessionState;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data.SqlClient;
using System.Text.RegularExpressions;
using System.IO;
using System.Drawing.Imaging;
using System.Text;
using System.Web.Security;


    /// <summary>
    /// StringUtil 的摘要说明。
    /// </summary>
    public class StringUtil
    {
        private static string passWord;	//加密字符串

        public StringUtil()
        {
            //
            // TODO: 在此处添加构造函数逻辑
            //
        }

        /// <summary>
        /// 判断输入是否数字
        /// </summary>
        /// <param name="num">要判断的字符串</param>
        /// <returns></returns>
        static public bool VldInt(string num)
        {
            try
            {
                Convert.ToInt32(num);
                return true;
            }
            catch { return false; }
        }

        /// <summary>
        /// 返回播放器替换后的字符串
        /// </summary>
        /// <param name="str">要替换的字符串</param>
        /// <returns></returns>
        static public string GetHtmlEditReplace(string str)
        {
            return str.Replace("&quot;", "\"").Replace("'", "''").Replace("&nbsp;", " ").Replace(",", "，").Replace("%","％");//.Replace("<","&lt;").Replace(">","&lt;") ;
        }

        /// <summary>
        /// 截取字符串函数
        /// </summary>
        /// <param name="str">所要截取的字符串</param>
        /// <param name="num">截取字符串的长度</param>
        /// <returns></returns>
        static public string GetSubString(string str, int num)
        {
            return (str.Length > num) ? str.Substring(0, num) + "..." : str;
        }

        /// <summary>
        /// 获取文本框中输入内容
        /// </summary>
        /// <param name="ctrl">TextBox控件ID</param>
        /// <returns></returns>
        static public string GetText(Control ctrl)
        {
            return ((TextBox)ctrl).Text.Replace("'", "\"");
        }

        /// <summary>
        /// 生成随机数
        /// </summary>
        /// <returns></returns>
        private string GenerateCheckCode()
        {
            int number;
            char code;
            string checkCode = String.Empty;

            System.Random random = new Random();

            for (int i = 0; i < 5; i++)
            {
                number = random.Next();

                if (number % 2 == 0)
                    code = (char)('0' + (char)(number % 10));
                else
                    code = (char)('A' + (char)(number % 26));

                checkCode += code.ToString();
            }

            HttpContext.Current.Response.Cookies.Add(new HttpCookie("CheckCode", checkCode));

            return checkCode;
        }


        /// <summary>
        /// 生成验证码图片
        /// </summary>
        public void CreateCheckCodeImage()
        {
            string checkCode = GenerateCheckCode();
            if (checkCode == null || checkCode.Trim() == String.Empty)
                return;

            System.Drawing.Bitmap image = new System.Drawing.Bitmap((int)Math.Ceiling((checkCode.Length * 12.5)), 22);
            Graphics g = Graphics.FromImage(image);

            try
            {
                //生成随机生成器
                Random random = new Random();

                //清空图片背景色
                g.Clear(Color.White);

                //画图片的背景噪音线
                for (int i = 0; i < 25; i++)
                {
                    int x1 = random.Next(image.Width);
                    int x2 = random.Next(image.Width);
                    int y1 = random.Next(image.Height);
                    int y2 = random.Next(image.Height);

                    g.DrawLine(new Pen(Color.Silver), x1, y1, x2, y2);
                }

                Font font = new System.Drawing.Font("Arial", 12, (System.Drawing.FontStyle.Bold | System.Drawing.FontStyle.Italic));
                System.Drawing.Drawing2D.LinearGradientBrush brush = new System.Drawing.Drawing2D.LinearGradientBrush(new Rectangle(0, 0, image.Width, image.Height), Color.Blue, Color.DarkRed, 1.2f, true);
                g.DrawString(checkCode, font, brush, 2, 2);

                //画图片的前景噪音点
                for (int i = 0; i < 100; i++)
                {
                    int x = random.Next(image.Width);
                    int y = random.Next(image.Height);

                    image.SetPixel(x, y, Color.FromArgb(random.Next()));
                }

                //画图片的边框线
                g.DrawRectangle(new Pen(Color.Silver), 0, 0, image.Width - 1, image.Height - 1);

                System.IO.MemoryStream ms = new System.IO.MemoryStream();
                image.Save(ms, System.Drawing.Imaging.ImageFormat.Gif);
                HttpContext.Current.Response.ClearContent();
                HttpContext.Current.Response.ContentType = "image/Gif";
                HttpContext.Current.Response.BinaryWrite(ms.ToArray());
            }
            finally
            {
                g.Dispose();
                image.Dispose();
            }
        }

        #region 加密的类型
        /// <summary>
        /// 加密的类型
        /// </summary>
        public enum PasswordType
        {
            SHA1,
            MD5
        }
        #endregion

        #region 字符串加密
        /// <summary>
        /// 字符串加密
        /// </summary>
        /// <param name="PasswordString">要加密的字符串</param>
        /// <param name="PasswordFormat">要加密的类别</param>
        /// <returns></returns>
        static public string EncryptPassword(string PasswordString, string PasswordFormat)
        {
            switch (PasswordFormat)
            {
                case "SHA1":
                    {
                        passWord = FormsAuthentication.HashPasswordForStoringInConfigFile(PasswordString, "SHA1");
                        break;
                    }
                case "MD5":
                    {
                        passWord = FormsAuthentication.HashPasswordForStoringInConfigFile(PasswordString, "MD5");
                        break;
                    }
                default:
                    {
                        passWord = string.Empty;
                        break;
                    }
            }
            return passWord;
        }
        #endregion
    }