asp.net几个是用函数-优快云博客

本文链接：https://blog.youkuaiyun.com/popotans/article/details/4699393

本文提供了一系列实用的C#代码片段，包括获取用户IP、字符串处理、HTML编码与解码、生成随机数、弹窗提示等功能。此外还介绍了如何通过URL获取网页内容、MD5加密方法及导出GridView到Excel的技术。

/// <summary>
/// 得到站点用户IP
/// </summary>
/// <returns></returns>
public static string getUserIP()
{
return HttpContext.Current.Request.ServerVariables[ "REMOTE_ADDR" ].ToString();
}
/// <summary>
/// 去除字符串最后一个','号
/// </summary>
/// <param name="chr">:要做处理的字符串</param>
/// <returns>返回已处理的字符串</returns>
public static string Lost( string chr)
{
if (chr == null || chr == string .Empty)
{
return "" ;
}
else
{
chr = chr.Remove(chr.LastIndexOf( "," ));
return chr;
}
}
/// <summary>
/// 去除字符串第一个'/'号
/// </summary>
/// <param name="chr">要做处理的字符串</param>
/// <returns>返回已处理的字符串</returns>
public static string lostfirst( string chr)
{
string flg = "" ;
if (chr != string .Empty || chr != null )
{
if (chr.Substring(0, 1) == "/" )
flg = chr.Replace(chr.Substring(0, 1), "" );
else
flg = chr;
}
return flg;
}
/// <summary>
/// 替换html中的特殊字符
/// </summary>
/// <param name="theString">需要进行替换的文本。</param>
/// <returns>替换完的文本。</returns>
public static string HtmlEncode( string theString)
{
theString = theString.Replace( ">" , ">" );
theString = theString.Replace( "<" , "<" );
theString = theString.Replace( " " , " " );
theString = theString.Replace( " " , " " );
theString = theString.Replace( "/"" , """ );
theString = theString.Replace( "/'" , "'" );
theString = theString.Replace( "/n" , "<br/> " );
return theString;
}
/// <summary>
/// 恢复html中的特殊字符
/// </summary>
/// <param name="theString">需要恢复的文本。</param>
/// <returns>恢复好的文本。</returns>
public static string HtmlDiscode( string theString)
{
theString = theString.Replace( ">" , ">" );
theString = theString.Replace( "<" , "<" );
theString = theString.Replace( " " , " " );
theString = theString.Replace( " " , " " );
theString = theString.Replace( """ , "/"" );
theString = theString.Replace( "'" , "/'" );
theString = theString.Replace( "<br/> " , "/n" );
return theString;
}
/// <summary>
/// 生成随机数字
/// </summary>
/// <param name="length">生成长度</param>
/// <returns></returns>
public static string Number( int Length)
{
return Number(Length, false );
}
/// <summary>
/// 生成随机数字
/// </summary>
/// <param name="Length">生成长度</param>
/// <param name="Sleep">是否要在生成前将当前线程阻止以避免重复</param>
/// <returns></returns>
public static string Number( int Length, bool Sleep)
{
if (Sleep)
System.Threading.Thread.Sleep(3);
string result = "" ;
System.Random random = new Random();
for ( int i = 0; i < Length; i++)
{
result += random.Next(10).ToString();
}
return result;
}
//弹出对话框
public static void salert( string str)
{
HttpContext.Current.Response.Write( "<script>alert('" + str + "');</script>" );
}
/// <summary>
/// 显示消息提示框，并回到前一页面
/// </summary>
/// <param name="page">当前页面指针，一般为this</param>
/// <param name="strMsg">提示信息</param>
public static void ShowGoHistory(System.Web.UI.Page page, string strMsg)
{
page.ClientScript.RegisterStartupScript(page.GetType(), "message" , "<script language='javascript' defer>alert('" + strMsg.ToString() + "');window.history.go(-1);</script>" );
}
/// <summary>
/// 显示消息提示对话框，并进行页面跳转
/// </summary>
/// <param name="page">当前页面指针，一般为this</param>
/// <param name="strMsg">提示信息</param>
/// <param name="url"> 跳转的目标URL</param>
public static void ShowRedirect(System.Web.UI.Page page, string strMsg, string url)
{
StringBuilder Builder = new StringBuilder();
Builder.Append( "<script language='javascript' defer>" );
Builder.AppendFormat( "alert('{0}');" , strMsg);
Builder.AppendFormat( "top.location.href='{0}'" , url);
Builder.Append( "</script>" );
page.ClientScript.RegisterStartupScript(page.GetType(), "message" , Builder.ToString());
}
//为了插入单引号
public static string delSingle( string str)
{
return str.Replace( "'" , "''" );
}
//由gridviw导出为Excel
public static void ToExcel(System.Web.UI.Control ctl)
{
HttpContext.Current.Response.AppendHeader( "Content-Disposition" , "attachment;filename=Excel.xls" );
HttpContext.Current.Response.Charset = "UTF-8" ;
HttpContext.Current.Response.ContentEncoding = System.Text.Encoding.Default;
HttpContext.Current.Response.ContentType = "application/ms-excel" ; //image/JPEG;text/HTML;image/GIF;vnd.ms-excel/msword
ctl.Page.EnableViewState = false ;
System.IO.StringWriter tw = new System.IO.StringWriter();
System.Web.UI.HtmlTextWriter hw = new System.Web.UI.HtmlTextWriter(tw);
ctl.RenderControl(hw);
HttpContext.Current.Response.Write(tw.ToString());
HttpContext.Current.Response.End();
}
///using System.Security.Cryptography;
///using System.Text;
/// <summary>
/// MD5函数
/// </summary>
/// <param name="str">原始字符串</param>
/// <returns>MD5结果</returns>
public static string MD5( string str)
{
byte [] b = Encoding.Default.GetBytes(str);
b = new MD5CryptoServiceProvider().ComputeHash(b);
string ret = "" ;
for ( int i = 0; i < b.Length; i++)
ret += b[i].ToString( "x" ).PadLeft(2, '0' );
return ret;
}
///using System.Net;
///using System.IO;
/// <summary>
/// 根据Url获得源文件内容
/// </summary>
/// <param name="url">合法的Url地址</param>
/// <returns></returns>
public static string GetSourceTextByUrl( string url)
{
WebRequest request = WebRequest.Create(url);
request.Timeout = 20000; //20秒超时
WebResponse response = request.GetResponse();
Stream resStream = response.GetResponseStream();
StreamReader sr = new StreamReader(resStream);
return sr.ReadToEnd();
}