第三章 循环结构
案例一：显示1至12月份
Label1.Text = "";
for (int i = 1; i <= 12; i++)
{
}
Label1.Text += i + "
月 "
;
案例二：显示鲜花分类
using
System;
using
System.Collections.Generic;
using
System.Linq;
using
System.Web;
using
System.Web.UI;
using
System.Web.UI.WebControls;
public
partial class _Default : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
protected void Button1_Click(object sender, EventArgs e)
{
Label1.Text = "";//
创建保存鲜花分类列表的字符串型数组
string[] flower = { "
红玫瑰"
, "
百合"
, "
蓝色妖姬"
, "
康乃馨"
, "
手提花篮"
};
string[] str= {"rose.aspx","lily.aspx","blue.aspx","carnation.aspx","basker.aspx"};
for (int i=0; i//
使用for循环显示列表
{
Label1.Text+="+str[i]+">"+flower[i]+"
";
";
}
}
}
案例三：显示日记
后台代码编写：
if (!IsPostBack)
{
ViewState["index"] = 0;
ViewState["riji"] = new string[31];
}
}
public string[] riji
{
get { return (string[])ViewState["riji"]; }
set { ViewState["riji"] = value; }
}
public int index
{
get { return (int)ViewState["index"]; }
set { ViewState["index"] = value; }
protected void Button1_Click(object sender, EventArgs e)
Label1.Text = "";
if (TextBox1.Text != "")
{
if (index < riji.Length)
{
riji[index] = "时间：" + DateTime.Now.ToString() + " " +"日记内容是：" + TextBox1.Text;
index++;
Label1.Text = "添加日记成功!";
TextBox1.Text = "";
}
else
{
Label1.Text = "一个月最多有31天";
}
}
else
{
Label1.Text = "请输入日记内容";
protected void Button2_Click(object sender, EventArgs e)
Label1.Text = "";
foreach (string xianshi in riji)
{
if (xianshi != null)
{
Label1.Text = Label1.Text + xianshi + "";
}
}
}
（3）进行验证：
点击添加日记，添加成功！
点击显示日记，显示成功！
点击清空显示，清空成功！
如果点击重写日记，那将会删除以前写过的日记：
案例四： 循环的中断
using
System;
using
System.Collections.Generic;
using
System.Linq;
using
System.Web;
using
System.Web.UI;
using
System.Web.UI.WebControls;
public
partial class _Default : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
protected void Button1_Click(object sender, EventArgs e)
{
int i = 0;
while (i < 100)//
循环i<100的数
{
if (i == 16)//
判断当i等于16时
break;//
中断循环
Label1.Text += Convert.ToString(i) + " ";
i++;
}
}
}
案例五：查询中奖号码
using
System;
using
System.Collections.Generic;
using
System.Linq;
using
System.Web;
using
System.Web.UI;
using
System.Web.UI.WebControls;
public
partial class _Default : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
protected void Button1_Click(object sender, EventArgs e)
{
Label1.Text = "
本注×××号码为："
;
Label2.Text = "
本期中奖号码为："
;
int[] num = { 3, 7, 19, 25, 27, 30, 33 };//
×××的号码
int[] win = { 3, 22, 66, 25, 90, 30, 33 }; //
中将的号码
int k = 0; //
计算中奖 号码个数计数器
int m = 0; //
×××的号码
int n = 0; //
中将的号码
while (m < num.Length)
{
Label1.Text += num[m] + " ";
m++;
}
while (n < win.Length)
{
Label2.Text += win[n] +" ";
n++;
}
for (int i = 0; i < num.Length; i++)
{
for (int j = 0; j < win.Length; j++)
{
if (num[i] == win[j])
{
k++;
}
}
}
switch (k)
{
case 7:
TextBox1 .Text = "
恭喜你！中了一个笔记本"
;
break ;
case 6:
TextBox1 .Text = "
恭喜你中了一个手机"
;
break ;
case 5:
TextBox1 .Text = "
恭喜你中了一个MP3"
;
break ;
case 4:
TextBox1 .Text = "
恭喜你中了一个U盘"
;
break ;
default :
TextBox1 .Text = "
恭喜你什么都没中"
;
break;
}
}
}
