C#中 常用的方法
1.绑定DropDownList下拉框数据。
/// <summary>
/// DropDownList绑定
/// </summary>
/// <param name="Drop">DropDownList的名称</param>
/// <param name="dt">数据源 DataTable类型</param>
/// <param name="TextField">绑定显示字段</param>
/// <param name="ValueField">绑定隐藏字段</param>
/// <param name="LastStrText">option显示字段</param>
/// <param name="LastStrValue">option隐藏字段</param>
public static void DropListBind(DropDownList Drop, DataTable dt, string TextField, string ValueField, string LastStrText, string LastStrValue)
{
BLL.t_JDKSB b_JDK = new LFMISPlat.BLL.t_JDKSB();
Drop.DataSource = dt;
Drop.DataTextField = TextField;
Drop.DataValueField = ValueField;
Drop.DataBind();
if (LastStrText != "")
{
ListItem itemAll = new ListItem();
itemAll.Text = LastStrText;
itemAll.Value = LastStrValue;
Drop.Items.Insert(0, itemAll);
}
}
- 当LastStrText为空字符串时，为标准绑定。有值的时候，将值追加到DropDownList最后一个Option中。
2.替换过多的文本为"......"来代替；
/// <summary>
/// 替换过多的文本为“。。。。。。”
/// </summary>
/// <returns></returns>
public static String ReplaceSign(string str)
{
if (str.Length > 10)
{
return str.Replace(str.Substring(10, (str.Length - (10))), "........");
}
else
{
return str;
}
}
例如：string str="abcdefghijklmnop"; 替换后 str="abcdefghij......";
3.替换代表的数字为文字
/// <summary>
/// 替换数字为正常或者异常
/// </summary>
/// <param name="strStatus"></param>
/// <returns></returns>
public static string GetStrChangeValue(string strStatus)
{
string strValue = "";
switch (strStatus)
{
case "0":
strValue = "<font size='2'>正常</font>";
break;
case "1":
strValue = "<font color='red' size='2'>异常</font>";
break;
default:
break;
}
return strValue;
}
4.计算本年有多少天
/// <summary>
/// 计算当前年有多少天
/// </summary>
/// <returns></returns>
public int DayOfYear()
{
DateTime firstDay = new DateTime(System.DateTime.Now.Year, 1, 1);
DateTime lastDay = new DateTime(System.DateTime.Now.Year + 1, 1, 1);
lastDay = lastDay.AddDays(-1);
int dayofYear = Math.Abs(((TimeSpan)(lastDay - firstDay)).Days);
return dayofYear;
}
5.检查字符串，看有没有非法字符，不允许输入已|分割
#region 检查字符串，看有没有非法字符不允许输入已|分割
/// <summary>
/// 检查字符串，看有没有非发字符不允许输入已|分割
/// </summary>
/// <param name="str"></param>
public static void check_str(string str)
{
string Illegal_Str = ",|&|+|'|\"|or|";
string[] newstr = Illegal_Str.Split('|');
for (int i = 0; i < (newstr.Length - 1); i++)
{
if (str.IndexOf(newstr[i]) != -1)
{
System.Web.HttpContext.Current.Response.Write("<script>alert('含有非法字符！');history.back()</script>");
}
}
}
#endregion
- 一般是在登陆的时候，验证用户名或密码的时候使用。
6.检查字符串，过滤or,and ',&,+,,,'',
/// <summary>
/// 字符串处理过滤or,and ',&,+,,,'',
/// </summary>
/// <returns></returns>
public static string newstr(string str)
{
//过滤or,and ',&,+,,,'',
String nstr = str.Replace("'", "").Replace("&", "").Replace(",", "").Replace("''", "");
return nstr;
}
7.获取客户端IP地址
#region 获取IP地址
/// <summary>
/// 获访问者的IP地址
/// xujh2 20140902
/// </summary>
[WebMethod]
public void getUserIp()
{
try
{
string result = System.Web.HttpContext.Current.Request.ServerVariables["HTTP_X_FORWARDED_FOR"];
//可能有代理
if (!string.IsNullOrWhiteSpace(result))
{
//没有"." 肯定是非IP格式
if (result.IndexOf(".") == -1)
{
HttpContextRequestEnd(failedEntity.retJsonError(reErrJson.error29));
return;
}
else
{
//有","，估计多个代理。取第一个不是内网的IP。
if (result.IndexOf(",") != -1)
{
result = result.Replace(" ", string.Empty).Replace("\"", string.Empty);
string[] temparyip = result.Split(",;".ToCharArray());
if (temparyip != null && temparyip.Length > 0)
{
for (int i = 0; i < temparyip.Length; i++)
{
//找到不是内网的地址
if (IsIPAddress(temparyip[i]) && temparyip[i].Substring(0, 3) != "10." && temparyip[i].Substring(0, 7) != "192.168" && temparyip[i].Substring(0, 7) != "172.16.")
{
HttpContextRequestEnd(temparyip[i].ToString().Trim());
return;
}
}
}
}
//代理即是IP格式
else if (IsIPAddress(result))
{
result = System.Web.HttpContext.Current.Request.UserHostAddress;
HttpContextRequestEnd(result.ToString().Trim());
return;
}
//代理中的内容非IP
else
{
HttpContextRequestEnd(result.ToString().Trim());
return;
}
}
}
//如果非代理IP则获取真正的IP
if (string.IsNullOrWhiteSpace(result))
{
result = System.Web.HttpContext.Current.Request.ServerVariables["REMOTE_ADDR"];
HttpContextRequestEnd(result.ToString().Trim());
return;
}
//如果前面两者都不是则获取近似的IP地址
if (string.IsNullOrWhiteSpace(result))
{
result = System.Web.HttpContext.Current.Request.UserHostAddress;
HttpContextRequestEnd(result.ToString().Trim());
return;
}
}
catch (Exception)
{
HttpContextRequestEnd(failedEntity.retJsonError(reErrJson.error0));
return;
}
//return "Hello World";
}
#endregion
