C# 常用代码

1.如何在ASP.NET中获得客户端IP地址
Request.UserHostAddress

2.如何取得一定范围内的随机数


//创建随机数对象


Random rnd = new Random();


//调用Next方法产生随机数


txtRnd.Text = rnd.Next(1,20).ToString();

3.如何取得文件的扩展名示例4.如何取得文件的扩展名示例


//取得指定的文件路径


string path = txtExtName.Text.Trim();


//txtExtName.Text = Path.GetExtension(path);


//取得指定路径中文件的扩展名


txtExtName.Text = path. Substring(path.LastIndexOf(".")+1);


txtExtName.Text = Path.GetExtension(selFile.PostedFile.FileName);

5.如何把字符串型数据转换为整型
try
{
//取得输入的数字
int strNum = Convert.ToInt32(txtStrNum.Text.Trim());
//把输入的数字扩大10倍
int NewNum = strNum * 10;
//显示新的数据
txtStrNum.Text = NewNum.ToString();
}
catch
{
Response.Write("请输入数字");
}

6、得到系统当前日期

DateTime.Now.ToShortDateString();

7. 得到系统时间

txtCurTime.Text = DateTime.Now.Year.ToString() + "-" + DateTime.Now.Month.ToString() + "-" +DateTime.Now.Day.ToString() + " "
+ DateTime.Now.Hour.ToString() + ":" +DateTime.Now.Minute.ToString() + ":" +DateTime.Now.Second.ToString();

8.取当前系统中的年

txtYear.Text = DateTime.Now.Year.ToString();

9.如何取得客户端的鼠标坐标并反馈到服务器端

<script language="javascript">
function document.onmousemove()
{
document.all("txtbox").value = event.screenX + "x" + event.screenY;
}
</script>

再将值传回服务器端。

10.判断星期几

string dt ,week="";

dt = DateTime.Now.DayOfWeek.ToString();
switch (dt)
{
case "Monday":
week= "星期一";
break;
case "Tuesday" :
week= "星期二";
break;
case "Wednesday":
week= "星期三";
break;
case "Thursday" :
week= "星期四";
break;
case "Friday" :
week= "星期五";
break;
case "Saturday":
week= "星期六";
break;
case "Sunday":
week = "星期日";
break;

}
txtWeek.Text = week;

11.判断指定年的总天数

//判断是否是闰年
if(DateTime.IsLeapYear(Convert.ToInt32(txtYearDay.Text)))
{
//如果是闰年
txtYearDay.Text = "366天";
}
else
{
//如果不是闰年
txtYearDay.Text = "365天";
}

12.当前月天数

int year,month,days=0;
year = DateTime.Now.Year ;
month = DateTime.Now.Month ;

//得到当前月的天数信息。
switch (month)
{
case 1:
days = 31;
break;
case 2:
if (DateTime.IsLeapYear(year))
{
//闰年二月为 29 天
days = 29;
}
else
{
//闰年二月为 28 天
days = 28;
}

break;
case 3:
days = 31;
break;
case 4:
days = 30;
break;
case 5:
days = 31;
break;
case 6:
days = 30;
break;
case 7:
days = 31;
break;
case 8:
days = 31;
break;
case 9:
days = 30;
break;
case 10:
days = 31;
break;
case 11:
days = 30;
break;
case 12:
days = 31;
break;
}

txtMonthDays.Text = days.ToString();

13.如何使用JMAIL组件实现邮件的发送

jmail.MessageClass oJmailMessage = new jmail.MessageClass();//建立发邮件类

oJmailMessage.Charset = "GB2312";// 字符集
oJmailMessage.Encoding = "BASE64";//附件的编码格式
oJmailMessage.ContentType = "text/html";
oJmailMessage.ISOEncodeHeaders = false;//是否将信头编码成iso-8859-1字符集
oJmailMessage.Priority = Convert.ToByte(1);// 优先级

oJmailMessage.From = TxtEmail.Text.Trim();//发送人邮件地址
oJmailMessage.FromName = TxtName.Text.Trim();//发送人姓名
oJmailMessage.Subject = txtSubject.Text.Trim();// 邮件主题
oJmailMessage.MailServerUserName = TxtSmtpUser.Text.Trim();//身份验证的用户名
oJmailMessage.MailServerPassWord = TxtSmtpPwd.Text.Trim();//用户密码

//添加一个收件人，抄送人和密送人的添加和该方法是一样的，只是分别使用AddRecipientCC和RecipientBCC两个属性
//要是需要添加多个收件人，则重复下面的语句即可。添加多个抄送和密送人的方法一样
oJmailMessage.AddRecipient(txtReciver.Text.Trim(),"","");
if("" != upFile.PostedFile.FileName)
{
string attpath = upFile.PostedFile.FileName;
oJmailMessage.AddAttachment(@attpath,true,attpath.Substring(attpath.LastIndexOf(".")+1,3));//添加附件
}
oJmailMessage.Body = txtContent.Text.Trim();//邮件内容

if(oJmailMessage.Send(TxtSmtServer.Text.Trim(),false))
{
Response.Write("发送成功！");
}
else
{
Response.Write("发送失败，请检查邮件服务器的设置！");
}

oJmailMessage = null;

14..如何使用JMAIL组件实现邮件的接收

jmail.POP3Class popMail = new POP3Class();//建立收邮件对象
jmail.Message mailMessage; //建立邮件信息接口
jmail.Attachments atts;//建立附件集接口
jmail.Attachment att;//建立附件接口

try
{
popMail.Connect(TxtPopUser.Text.Trim(),TxtPopPwd.Text.Trim(),TxtPopServer.Text.Trim(),Convert.ToInt32(TxtPopPort.Text.Trim()));

if(0 < popMail.Count) //如果收到邮件
{
for(int i=1;i <= popMail.Count;i++) //根据取到的邮件数量依次取得每封邮件
{
mailMessage = popMail.Messages[i]; //取得一条邮件信息
atts = mailMessage.Attachments; //取得该邮件的附件集合
mailMessage.Charset = "GB2312"; //设置邮件的编码方式
mailMessage.Encoding = "Base64"; //设置邮件的附件编码方式
mailMessage.ISOEncodeHeaders = false; //是否将信头编码成iso-8859-1字符集
txtpriority.Text = mailMessage.Priority.ToString(); //邮件的优先级
txtSendMail.Text = mailMessage.From; //邮件的发送人的信箱地址
txtSender.Text = mailMessage.FromName; //邮件的发送人
txtSubject.Text = mailMessage.Subject; //邮件主题
txtBody.Text = mailMessage.Body; //邮件内容
txtSize.Text = mailMessage.Size.ToString(); //邮件大小

for(int j=0;j<atts.Count;j++)
{
att = atts[j]; //取得附件
string attname = att.Name; //附件名称

att.SaveToFile("e://attFile//"+attname); //上传到服务器

}

}
panMailInfo.Visible = true;
att = null;
atts = null;
}
else
{
Response.Write("没有新邮件!");
}

popMail.DeleteMessages();
popMail.Disconnect();
popMail = null;
}
catch
{
Response.Write("Warning!请检查邮件服务器的设置是否正确！");
}