亮亮大家常用的公共类吧！

[七色鸟]

刚到一新衙门，发现老的项目中居然啊公共类都没有的。
什么，替换文本中HTML标签内容，和截取字符串长度(按照字节截取)，这些都没的。

大家亮亮自己的吧！

[天下在我心]

自己写一个吧，很简单的。

[魏飞翔]

http://topic.csdn.net/u/20090815/08/1AA82791-A7A2-4640-80B4-907F5771D676.html

[叶黑]

sqlDALHelper 别人写的

[暗尘掩月]

http://blog.csdn.net/anchenyanyue

[事理]

贴几个我项目中用到的。

/// <summary>
    /// 截取指定长度中英文字符串(宽度一样)
    /// </summary>
    /// <param name="str">要截取的字符串</param>
    /// <param name="length">截取长度,中文字符长度</param>
    /// <returns>截取后的字符串</returns>
    public static string CutStr(object str, int length)
    {
        if (str == null) return string.Empty;

        Encoding encoding = Encoding.GetEncoding("gb2312");

        int len = length * 2;
        int j = 0, k = 0;

        string cutStr = str.ToString();

        for (int i = 0; i < cutStr.Length; i++)
        {
            byte[] bytes = encoding.GetBytes(cutStr.Substring(i, 1));
            if (bytes.Length == 2)//不是英文
                j += 2;
            else
                j++;

            if (j <= len)
                k += 1;

            if (j >= len)
                return cutStr.Substring(0, k) + "...";
        }
        return cutStr;
    }

    /// <summary>
    /// 下载指定路径文件
    /// </summary>
    /// <param name="path">文件绝对路径</param>
    public static void DownLoadFile(string path)
    {
        System.IO.FileInfo fi = new System.IO.FileInfo(path);
        if (fi.Exists)
        {
            //判断文件是否正在使用
            try
            {
                using (System.IO.FileStream fs = System.IO.File.Open(path, System.IO.FileMode.Append, System.IO.FileAccess.Write, System.IO.FileShare.None))
                {
                }
            }
            catch (Exception ex)
            {
                throw;
            }
            System.Web.HttpContext.Current.Response.Clear();
            System.Web.HttpContext.Current.Response.AddHeader("Content-Disposition", "attachment;filename=" + HttpUtility.UrlEncode(path.Substring(path.LastIndexOf("\\") + 1), System.Text.Encoding.UTF8));
            System.Web.HttpContext.Current.Response.AddHeader("Content-Length", fi.Length.ToString());
            System.Web.HttpContext.Current.Response.ContentType = "application/octet-stream;charset=gb2321";
            System.Web.HttpContext.Current.Response.WriteFile(fi.FullName);
            System.Web.HttpContext.Current.Response.Flush();
            System.Web.HttpContext.Current.Response.Close();
        }
        else
        {
            System.Web.HttpContext.Current.Response.Write("<script>alert('源文件不存在！');</script>");
        }
    }
    /// <summary>
    /// 获取枚举的描述信息
    /// </summary>
    /// <param name="en">枚举</param>
    /// <returns></returns>
    public static string GetEnumDescription(this Enum en)
    {
        Type type = en.GetType();
        System.Reflection.MemberInfo[] memInfo = type.GetMember(en.ToString());
        if (memInfo != null && memInfo.Length > 0)
        {
            object[] attrs = memInfo[0].GetCustomAttributes(typeof(System.ComponentModel.DescriptionAttribute), false);
            if (attrs != null && attrs.Length > 0)
                return ((System.ComponentModel.DescriptionAttribute)attrs[0]).Description;
        }
        return en.ToString();
    }

/// <summary>
/// 通用应用程序缓存辅助类
/// </summary>
public static class CacheHelper
{
    public delegate T GetDataMethod<T>();//获取数据的方法

    /// <summary>
    /// 通用应用程序缓存方法,缓存数据10分钟
    /// </summary>
    /// <typeparam name="T">缓存数据的类型，一般是集合，如IList<UsersData></typeparam>
    /// <param name="key">键</param>
    /// <param name="getDataMethod">获取数据的方法</param>
    /// <returns>数据列表</returns>
    public static T GetCache<T>(string key, GetDataMethod<T> getDataMethod)
    {
        //T dataList = getDataMethod();        
        //return dataList;

        if (HttpRuntime.Cache[key] == null)
        {
            T dataList = getDataMethod();

            HttpRuntime.Cache.Add(key, dataList, null, DateTime.Now.AddMinutes(10),
                TimeSpan.Zero, System.Web.Caching.CacheItemPriority.High, null);
            return dataList;
        }
        return (T)HttpRuntime.Cache[key];
    }

    /// <summary>
    /// 移除应用程序缓存
    /// </summary>
    /// <param name="key">键</param>
    public static void RemoveCacheByKey(string key)
    {
        HttpRuntime.Cache.Remove(key);
    }
}

    /// <summary> 
    /// 获取用户IP地址
    /// </summary> 
    public static string IPAddress
    {
        get
        {
            //string ipAddress = HttpContext.Current.Request.ServerVariables["HTTP_X_FORWARDED_FOR"];
            //HTTP_X_FORWARDED_FOR获取的用户真实ip可能存在欺骗，所以忽略通过代理的访问的用户真实ip地址，记录代理ip

            string ipAddress = HttpContext.Current.Request.ServerVariables["REMOTE_ADDR"];
            if (string.IsNullOrEmpty(ipAddress))
                ipAddress = HttpContext.Current.Request.UserHostAddress;

            if (ipAddress.Length > 15) //是ipv6格式ip，转换为ipv4
            {
                //取得客户端主机 IPv4 位址(通过DNS反查)
                string ipv4 = string.Empty;
                foreach (System.Net.IPAddress ip in System.Net.Dns.GetHostAddresses(ipAddress))
                {
                    if (ip.AddressFamily == System.Net.Sockets.AddressFamily.InterNetwork)
                    {
                        ipv4 = ip.ToString();
                        break;
                    }
                }
                if (ipv4.Length == 0)
                {
                    foreach (System.Net.IPAddress ip2 in System.Net.Dns.GetHostEntry(ipAddress).AddressList)
                    {
                        if (ip2.AddressFamily == System.Net.Sockets.AddressFamily.InterNetwork)
                        {
                            ipv4 = ip2.ToString();
                            break;
                        }
                    }
                }
                return ipv4.Length > 0 ? ipv4 : string.Empty;
            }
            return ipAddress;
        }
    }
    #region Cookie操作

    /// <summary>
    /// 设置指定Cookie名称的值
    /// </summary>
    /// <param name="cookieName">cookie名称</param>
    /// <param name="cookieValue">值</param>
    /// <param name="expires">过期时间，DateTime.MinValue表示默认过期时间</param>
    public static void AddCookie(string cookieName, string cookieValue, DateTime expires)
    {
        HttpContext.Current.Response.Cookies[cookieName].Value = string.Empty;
        HttpContext.Current.Response.Cookies[cookieName].Value = cookieValue;
        if (expires != DateTime.MinValue)
            HttpContext.Current.Response.Cookies[cookieName].Expires = expires;
    }

    /// <summary>
    /// 读取指定cookie名称的值
    /// </summary>
    /// <param name="cookieName">cookie名称</param>
    /// <returns>值</returns>
    public static string GetCookie(string cookieName)
    {
        string cookieValue = string.Empty;

        try
        {
            cookieValue = HttpContext.Current.Request.Cookies[cookieName].Value;
        }
        catch { }

        return cookieValue;
    }

    /// <summary>
    /// 删除指定名称cookie
    /// </summary>
    /// <param name="cookieName">cookie名称</param>
    public static void RemoveCookie(string cookieName)
    {
        HttpContext.Current.Response.Cookies[cookieName].Expires = DateTime.MinValue;
    }

    #endregion

[事理]

/// <summary>
/// 消息提示类,简化页面消息提示
/// </summary>
public static class MessageBox
{
const string javaScriptHead = "<script type='text/javascript'>";
const string javaScriptFoot = "</script>";

/// <summary>
/// Page.ClientScript.RegisterStartupScript提示消息
/// 注意:模版页中提示消息不能用此方法;消息中有换行用\\r\\n
/// </summary>
/// <remarks>
/// MessageBox.Show("提示信息！",this);
/// </remarks>
/// <param name="message">提示信息</param>
/// <param name="page">页面对象,一般传入this</param>
public static void Show(string message, Page page)
{
Type pageType = page.GetType();
page.ClientScript.RegisterStartupScript(pageType, pageType.Name, javaScriptHead + "alert('" + message.Replace("'", " ") + "')" + javaScriptFoot);
}

/// <summary>
/// ScriptManager.RegisterStartupScript提示消息
/// </summary>
/// <param name="message">提示信息</param>
/// <param name="updatePanel">UpdatePanel对象</param>
public static void Show(string message, UpdatePanel updatePanel)
{
ScriptManager.RegisterStartupScript(updatePanel, updatePanel.Page.GetType(), updatePanel.ID, "alert('" + message.Replace("'", " ") + "');", true);
}

/// <summary>
/// confirm确认提示消息后，跳转到指定页面，Page.ClientScript.RegisterStartupScript提示消息
/// </summary>
/// <remarks>
/// MessageBox.ShowConfirmAndRedirect("提示消息！","Success.aspx",this);
/// </remarks>
/// <param name="message">提示消息</param>
/// <param name="url">跳转的页面</param>
/// <param name="page">页面对象,一般传入this</param>
public static void ShowConfirmAndRedirect(string message, string url, Page page)
{
string script = "var ok=false;";

if (!string.IsNullOrEmpty(message))
script = "ok=confirm('" + message.Replace("'", " ") + "');";
if (!string.IsNullOrEmpty(url))
script += "if(ok==true)top.location.href='" + url + "'";

script = javaScriptHead + script + javaScriptFoot;

Type pageType = page.GetType();
page.ClientScript.RegisterStartupScript(pageType, pageType.Name, script);
}

/// <summary>
/// 提示消息后刷新指定父页面，Page.ClientScript.RegisterStartupScript提示消息
/// </summary>
/// <param name="message">提示消息</param>
/// <param name="url">父窗口要跳转的页面</param>
/// <param name="page">页面对象,一般传入this</param>
public static void ShowAndRefreshParent(string message, string url, Page page)
{
string script = string.Empty;

if (!string.IsNullOrEmpty(message))
script = "alert('" + message.Replace("'", " ") + "');";
if (!string.IsNullOrEmpty(url))
script += "window.opener.location.href='" + url + "';window.close();";

script = javaScriptHead + script + javaScriptFoot;

Type pageType = page.GetType();
page.ClientScript.RegisterStartupScript(pageType, pageType.Name, script);
}

/// <summary>
/// window.open打开窗口
/// </summary>
/// <param name="url">要打开的页面</param>
/// <param name="width">窗口宽度</param>
/// <param name="height">窗口高度</param>
/// <param name="page">页面对象,一般传入this</param>
public static void OpenWindow(string url, int width, int height, Page page)
{
string script = javaScriptHead + "var newwindow=window.open('" + url + "','_blank','width=" + width + ",height=" + height
+ ",top='+(screen.height-" + height + ")/2+',left='+(screen.width-" + width
+ ")/2+',toolbar=no,menubar=no,scrollbars=yes,resizable=no,location=no,status=no');newwindow.focus();"
+ javaScriptFoot;

Type pageType = page.GetType();
page.ClientScript.RegisterStartupScript(pageType, pageType.Name, script);
}

/// <summary>
/// 弹出居中模态窗口
/// </summary>
/// <param name="url">页面地址</param>
/// <param name="width">模态窗口宽度</param>
/// <param name="height">模态窗口高度</param>
/// <param name="page">页面对象,一般传入this</param>
public static void ShowModalDialog(string url, int width, int height, Page page)
{
string script = javaScriptHead + "window.showModalDialog('" + url + "','','dialogWidth:" + width + "px;dialogHeight:" + height
+ "px;dialogTop:'+(screen.height-" + height + ")/2+'px;dialogLeft:'+(screen.width-" + width
+ ")/2+'px;center:1;scroll:no;status:no;');" + javaScriptFoot;

Type pageType = page.GetType();
page.ClientScript.RegisterStartupScript(pageType, pageType.Name, script);
}

#region Response.Write 提示消息

/// <summary>
/// Response提示消息后跳转到指定页面
/// window.location.href
/// </summary>
/// <param name="message">提示信息</param>
/// <param name="url">跳转的页面</param>
public static void ResponseMsgAndRedirect(string message, string url)
{
string script = string.Empty;

if (!string.IsNullOrEmpty(message))
script = "alert('" + message.Replace("'", " ") + "');";
if (!string.IsNullOrEmpty(url))
script += "window.location.href='" + url + "'";

script = javaScriptHead + script + javaScriptFoot;

System.Web.HttpContext.Current.Response.Write(script);
}

/// <summary>
/// Response提示消息后，子页面触发父页面跳转，适用于iframe
/// parent.location.href
/// </summary>
/// <param name="message">提示信息</param>
/// <param name="url">要跳转页面</param>
public static void ResponseMsgAndParentRedirect(string message, string url)
{
string script = string.Empty;

if (!string.IsNullOrEmpty(message))
script = "alert('" + message.Replace("'", " ") + "');";
if (!string.IsNullOrEmpty(url))
script += "parent.location.href='" + url + "'";

script = javaScriptHead + script + javaScriptFoot;

System.Web.HttpContext.Current.Response.Write(script);
}

/// <summary>
/// Response提示消息后，最顶层的页面跳转，适用于iframe中子页面触发顶层页面跳转
/// top.location.href
/// </summary>
/// <param name="message">提示信息</param>
/// <param name="url">要跳转的页面</param>
public static void ResponseMsgAndTopRedirect(string message, string url)
{
string script = string.Empty;

if (!string.IsNullOrEmpty(message))
script = "alert('" + message.Replace("'", " ") + "');";
if (!string.IsNullOrEmpty(url))
script += "top.location.href='" + url + "'";

script = javaScriptHead + script + javaScriptFoot;

System.Web.HttpContext.Current.Response.Write(script);
}

/// <summary>
/// Response提示消息后返回指定页面
/// </summary>
/// <param name="message">提示信息</param>
/// <param name="historyCount">history.go(historyCount)</param>
public static void ResponseMsgAndHistoryBack(string message, int historyCount)
{
string script = string.Empty;

if (!string.IsNullOrEmpty(message))
script = "alert('" + message.Replace("'", " ") + "');";

script = javaScriptHead + script + "history.go(" + historyCount + ")" + javaScriptFoot;

System.Web.HttpContext.Current.Response.Write(script);
}
#endregion
}

[事理]

/// <summary>
/// 过滤xss攻击脚本
/// </summary>
public static class XSSFilter
{
/// <summary>
/// 过滤xss攻击脚本
/// </summary>
/// <param name="html">传入字符串</param>
/// <returns>过滤后的字符串</returns>
public static string Filter(string html)
{
if (string.IsNullOrEmpty(html)) return string.Empty;
// CR(0a) ，LF(0b) ，TAB(9) 除外，过滤掉所有的不打印出来字符.
// 目的防止这样形式的入侵 ＜java\0script＞
// 注意：\n, \r, \t 可能需要单独处理，因为可能会要用到
string ret = System.Text.RegularExpressions.Regex.Replace(html, "([\x00-\x08][\x0b-\x0c][\x0e-\x20])", string.Empty);

//替换所有可能的16进制构建的恶意代码
//<IMG SRC=@avascript:a&_#X6Cert('XSS')>
string chars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890!@#$%^&*()~`;:?+/={}[]-_|'\"\\";
for (int i = 0; i < chars.Length; i++)
{
ret = System.Text.RegularExpressions.Regex.Replace(ret, string.Concat("(&#[x|X]0{0,}", Convert.ToString((int)chars[i], 16).ToLower(), ";?)"),
chars[i].ToString(), System.Text.RegularExpressions.RegexOptions.IgnoreCase);
}

//过滤\t, \n, \r构建的恶意代码
string[] keywords = {"javascript", "vbscript", "expression", "applet", "meta", "xml", "blink",
"link", "style", "script","object", "iframe", "frame", // "embed",
"frameset", "ilayer", "layer", "bgsound", "title", "base" ,"onabort",
"onactivate", "onafterprint", "onafterupdate", "onbeforeactivate",
"onbeforecopy", "onbeforecut", "onbeforedeactivate",
"onbeforeeditfocus", "onbeforepaste", "onbeforeprint", "onbeforeunload",
"onbeforeupdate", "onblur", "onbounce", "oncellchange", "onchange",
"onclick", "oncontextmenu", "oncontrolselect", "oncopy", "oncut",
"ondataavailable", "ondatasetchanged", "ondatasetcomplete", "ondblclick",
"ondeactivate", "ondrag", "ondragend", "ondragenter", "ondragleave",
"ondragover", "ondragstart", "ondrop", "onerror", "onerrorupdate",
"onfilterchange", "onfinish", "onfocus", "onfocusin", "onfocusout",
"onhelp", "onkeydown", "onkeypress", "onkeyup", "onlayoutcomplete",
"onload", "onlosecapture", "onmousedown", "onmouseenter", "onmouseleave",
"onmousemove", "onmouseout", "onmouseover", "onmouseup", "onmousewheel",
"onmove", "onmoveend", "onmovestart", "onpaste", "onpropertychange",
"onreadystatechange", "onreset", "onresize", "onresizeend", "onresizestart",
"onrowenter", "onrowexit", "onrowsdelete", "onrowsinserted", "onscroll",
"onselect", "onselectionchange", "onselectstart", "onstart", "onstop",
"onsubmit", "onunload"};

bool found = true;
while (found)
{
var retBefore = ret;

StringBuilder pattern = new StringBuilder(1000);
StringBuilder pattern2 = new StringBuilder(1000);
for (int i = 0; i < keywords.Length; i++)
{
pattern.Remove(0, pattern.Length);
pattern.Append("<");
pattern2.Remove(0, pattern2.Length);
pattern2.Append("/");
for (int j = 0; j < keywords[i].Length; j++)
{
if (j > 0)
{
pattern.Append("((&#[x|X]0{0,8}([9][a][b]);?)?|({0,8}([9][10][13]);?)?)?");
pattern2.Append("((&#[x|X]0{0,8}([9][a][b]);?)?|({0,8}([9][10][13]);?)?)?");
}
pattern.Append(keywords[i][j]);
pattern2.Append(keywords[i][j]);
}
string replacement = string.Concat(keywords[i].Substring(0, 2), "＜x＞", keywords[i].Substring(2));
ret = System.Text.RegularExpressions.Regex.Replace(ret, pattern.ToString(), replacement, System.Text.RegularExpressions.RegexOptions.IgnoreCase);
ret = System.Text.RegularExpressions.Regex.Replace(ret, pattern2.ToString(), replacement, System.Text.RegularExpressions.RegexOptions.IgnoreCase);
if (ret == retBefore)
found = false;
}

}
return ret;
}
}

[七色鸟]

slyzly,兄弟，你真给力。等会分多给你一点。

[七色鸟]

另一种，按照字节截取方式。

   public static string CutString(this string value, int length)
    {
        if (string.IsNullOrEmpty(value)) return "";

        int dataLength = length * 2;  //要截取的字节长度
        byte[] bLength = Encoding.GetEncoding("gb2312").GetBytes(value);  //原字符串的字节长度

        if (bLength.Length <= dataLength)
            return value;

        string strEndRes = "";
        while (true)
        {
            strEndRes += value.Substring(strEndRes.Length, length);

            int size = dataLength - Encoding.GetEncoding("gb2312").GetBytes(strEndRes).Length;
            if (size <= 1)
            {
                if (size == 1 && Encoding.GetEncoding("gb2312").GetBytes(value.Substring(strEndRes.Length, 1)).Length == 1)
                {
                    strEndRes += value.Substring(strEndRes.Length, 1);
                }
                return strEndRes;
            }
            length = size / 2;
        }
    }

[你们是不是在找BUG]

之前做项目，导入了一堆的公共类，然后讲了一通，最后review发现，根本没人用~~~~
好伤心~~~~

[鸭梨山大帝]

这就是最悲剧的地方。。。 。。。

[Quote=引用 10 楼 的回复:]

之前做项目，导入了一堆的公共类，然后讲了一通，最后review发现，根本没人用~~~~
好伤心~~~~
[/Quote]

[种草德鲁伊]

编译以后有差不多500kB，当然了不是给别人用的。