C# WinForm基础

1. WinForm基础

Form1.cs

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
namespace WinsForm基础
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
string name = textBox1.Text;//得到编辑框中的文字
//this.Text = name + "你好";//设置这个窗体的文字
this.Text = string.Format("{0}你好", name);
//当点击文本框时，隐藏文本框
textBox1.Hide();
}
private void button2_Click(object sender, EventArgs e)
{
string str2 = textBox2.Text;
string str3 = textBox3.Text;
int i1, i2;
if (!int.TryParse(str2, out i1))
//out传参前，可以不对参数初始化,out的函数会清空变量，即使变量已经赋值也不行;
//ref传参前，必须对参数初始化
{
MessageBox.Show("第一个数不是合法的整数");
return;//不要忘了return
}
if (!int.TryParse(str3, out i2))
{
MessageBox.Show("第二个数不是合法的整数");
return;
}
int i3 = i1 + i2;
textBox4.Text = Convert.ToString(i3);
}
}
}

2. email分析

Form1.cs

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
namespace email分析
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
string email = textBox1.Text;
string[] strs = email.Split('@');
if (strs.Length != 2)
{
MessageBox.Show("非法的email地址!");
return;//不要忘了return
}
textBox2.Text = strs[0];
textBox3.Text = strs[1];
}
private void Form1_Load(object sender, EventArgs e)
{
}
}
}

3. 滚动1

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
namespace 滚动1
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
string str = textBox1.Text;
char first = str[0];
string 剩下 = str.Substring(1);
textBox1.Text = 剩下 + first;
}
private void button2_Click(object sender, EventArgs e)
{
string str = textBox1.Text;
char last = str[4];
string 剩下 = str.Substring(0,4);
textBox1.Text = last+剩下;
}
private void Form1_Load(object sender, EventArgs e)
{
}
}
}

4. 累加

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
namespace 累加
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void Form1_Load(object sender, EventArgs e)
{
}
private void button1_Click(object sender, EventArgs e)
{
string s1 = textBox1.Text;
string s2 = textBox2.Text;
int i1, i2;
if (int.TryParse(s1, out i1) == false)
{
MessageBox.Show("数字1格式错误!");
return;
}
if (int.TryParse(s2, out i2) == false)
{
MessageBox.Show("数字2格式错误!");
return;
}
if (i1 >= i2)
{
MessageBox.Show("第二个数要大于第一个数!");
return;
}
int sum = 0;
for (int i = i1; i <= i2; i++)
{
sum = sum + i;
}
textBox3.Text = Convert.ToString(sum);
}
}
}

5. 登录界面1

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
namespace 登录界面1
{
public partial class Form1 : Form
{
private int ErrorTimes = 0;//错误的次数
public Form1()
{
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
//方法一
textBox4.AppendText(DateTime.Now.ToString()+"\n");
//方法二
//textBox4.Text = textBox4.Text+ DateTime.Now.ToString() + "\n" ;
}
private void login_Click(object sender, EventArgs e)
{
string username = txtUserName.Text.Trim();//Trim忽略大小写
string password = txtPassWord.Text;
if (username.Equals("admin", StringComparison.
OrdinalIgnoreCase) && password == "888888")
{
MessageBox.Show("登录成功!");
}
else
{
ErrorTimes++;//错误次数加1
if (ErrorTimes > 3)
{
MessageBox.Show("错误次数过多,程序即将退出!");
Application.Exit();
}
MessageBox.Show("登录失败!");
}
}
private void btnModify_Click(object sender, EventArgs e)
{
string oldpassword = txtUserName.Text;//取旧密码
string newpassword = txtPassWord.Text;
string newpassword2 = newPassWord2.Text;
if (oldpassword != "888888")
{
MessageBox.Show("旧密码错误!");
return;
}
if (newpassword != newpassword2)
{
MessageBox.Show("两次输入的新密码不一致!");
return;
}
if (newpassword == oldpassword)
{
MessageBox.Show("旧密码和新密码不能一样!");
return;
}
MessageBox.Show("修改成功!");
}
}
}

6. 图片显示1

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
namespace 图片显示1
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
string 身份证号 = textBox1.Text;
//叫验是否是合法的身份证号
pictureBox1.Visible = true;
string strYear = 身份证号.Substring(6,4);
int year = Convert.ToInt32(strYear);
if ((DateTime.Now.Year - year >= 18)==true)
{
pictureBox1.Visible = true;
return;
}
else
{
MessageBox.Show("你的年龄小于18,无法查看!");
//pictureBox1.Visible = false;
return;
}
}
}
}

7. 统计成绩

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
namespace 统计成绩
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void btnResult_Click(object sender, EventArgs e)
{
//string s = txt成绩.Text;
//方法1:按照\r\n进行split
string[] lines=txt成绩.Lines;//方法2
string maxName="";
int maxScore = -1;
foreach (string line in lines)
{
string[] strs = line.Split('=');
string name=strs[0];
string strScore=strs[1];
int score = Convert.ToInt32(strScore);
if (score > maxScore)
{
maxName = name;
maxScore = score;
}
}
MessageBox.Show(string.Format("{0}是第一名,成绩是{1}",
maxName,maxScore));
}
}
}

8. 下拉列表

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
namespace 下拉列表
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void comboBox1_Click(object sender, EventArgs e)
{
MessageBox.Show(Convert.ToString
(comboBox1.SelectedIndex));//第几项
MessageBox.Show(Convert.ToString
(comboBox1.SelectedValue));
MessageBox.Show(Convert.ToString
(comboBox1.SelectedText));//数据库中将用到
MessageBox.Show(Convert.ToString
(comboBox1.SelectedItem));//选中的项的内容
}
private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
{
MessageBox.Show(Convert.ToString(comboBox1.SelectedItem));
}
private void btnResult_Click(object sender, EventArgs e)
{
string str1 = txtNumber1.Text;
string str2 = txtNumber2.Text;
int i1 = Convert.ToInt32(str1);
int i2 = Convert.ToInt32(str2);
int result;
switch (cb操作符.SelectedIndex)
{
case 0://+
result = i1 + i2;
break;
case 1://-
result = i1 - i2;
break;
case 2://*
result = i1 * i2;
break;
case 3:// /
if (i2 == 0)
{
MessageBox.Show("0不能为除数!");
return;
}
result = i1 / i2;
break;
default:
throw new Exception("未知的运算符");
}
txtResult.Text = Convert.ToString(result);
}
}
}

9. 省市选择

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
namespace 省市选择
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void cb省_SelectedIndexChanged(object sender, EventArgs e)
{
cb市.Items.Clear();//清空旧数据
string 省 = Convert.ToString(cb省.SelectedItem);
if(省=="山东")
{
cb市.Items.Add("潍坊");
cb市.Items.Add("临沂");
cb市.Items.Add("青岛");
}
if (省 == "河南")
{
cb市.Items.Add("郑州");
cb市.Items.Add("三门峡");
cb市.Items.Add("洛阳");
}
if (省 == "湖南")
{
cb市.Items.Add("长沙");
cb市.Items.Add("衡阳");
cb市.Items.Add("邵阳");
}
}
}
}