winForm实例
//简单计算器(加法):
1 private void button1_Click(object sender, EventArgs e) 2 { 3 string str1 = textBox1.Text; 4 string str2 = textBox2.Text; 5 int i1, i2;//接受值 6 if (int.TryParse(str1, out i1)) 7 { 8 MessageBox.Show("第一个数不是合法的整数");//弹出窗口信息 9 10 } 11 if (int.TryParse(str2, out i2) == false) 12 { 13 MessageBox.Show("第二个数不是合法的整数"); 14 return;//不要忘了return 15 } 16 int i3 = i1 + i2; 17 textBox3.Text = Convert.ToString(i3);//i3.ToString(); 18 }
//统计成绩:
1 //string s = txt成绩.Text;//方法1,按照\r\n进行split 2 string[] lines= txt成绩.Lines; 3 string maxName = ""; 4 int maxScore = -1; 5 foreach (string line in lines) 6 { 7 string[] strs = line.Split('='); 8 string name = strs[0]; 9 string strScore = strs[1]; 10 int score = Convert.ToInt32(strScore); 11 if (score > maxScore) 12 { 13 maxName = name; 14 maxScore = score; 15 } 16 } 17 MessageBox.Show(string.Format("{0}是第一名,成绩{1}", maxName, maxScore));
//身份证判断
1 string 身份证号 = textBox1.Text; 2 //校验是否是合法的身份证号 不考虑X 3 //131226198105223452 4 pictureBox1.Visible = true; 5 string strYear = 身份证号.Substring(6, 4);//从6开始 取长度为4 6 int year = Convert.ToInt32(strYear); 7 if (DateTime.Now.Year - year > 18) 8 { 9 pictureBox1.Visible = true; 10 } 11 else 12 { 13 pictureBox1.Visible = false; 14 }
//累加
1 private void button1_Click(object sender, EventArgs e) 2 { 3 string s1 = textBox1.Text; 4 string s2 = textBox2.Text; 5 int i1, i2; 6 if (int.TryParse(s1, out i1) == false) 7 { 8 MessageBox.Show("数字1格式错误"); 9 } 10 if (int.TryParse(s2, out i2) == false) 11 { 12 MessageBox.Show("数字1格式错误"); 13 } 14 int sum = 0; 15 for (int i = 0; i <= i2; i++) 16 { 17 sum += i;// sum=sum+i 18 } 19 textBox3.Text = Convert.ToString(sum); 20 }
//省市选择器
1 private void cb省_SelectedIndexChanged(object sender, EventArgs e) 2 { 3 cb市.Items.Clear();//清空旧数据 4 string 省 = Convert.ToString(cb省.SelectedItem); 5 if (省 == "山东") 6 { 7 cb市.Items.Add("滩坊"); 8 cb市.Items.Add("临沂"); 9 cb市.Items.Add("青岛"); 10 } 11 if (省 == "河南") 12 { 13 cb市.Items.Add("郑州"); 14 cb市.Items.Add("三门峡"); 15 cb市.Items.Add("洛阳"); 16 } 17 if (省 == "辽宁") 18 { 19 cb市.Items.Add("沈阳"); 20 cb市.Items.Add("鞍山"); 21 cb市.Items.Add("本溪"); 22 } 23 //cb市.Items.Add("aaaaaa"); 24 }
//登录设置
1 public partial class Form1 : Form 2 { 3 private int ErrorTimes = 0;//类的变量 4 public Form1() 5 { 6 7 InitializeComponent(); 8 } 9 10 private void btnLogin_Click(object sender, EventArgs e) 11 { 12 string username = txtUserName.Text.Trim();//Trim禁止用户帐号为空格 13 string password = txtPassword.Text; 14 if (username.Equals("admin", StringComparison.OrdinalIgnoreCase) && password == "888888") 15 { 16 MessageBox.Show("登录成功"); 17 } 18 else 19 { 20 /* 21 int i = 0; 22 i++; 23 if (i >= 3) 24 { 25 MessageBox.Show("错误次数过多,程序即将退出!"); 26 Application.Exit(); 27 }*/ 28 ErrorTimes++; 29 //局部变量每次运行完毕变量的值都会被销毁,下次再运行,会重新初始化。而类的字段,只要是一个对象,那么只要对象不销毁,就会一直保持对象的字段值 30 if (ErrorTimes >= 3) 31 { 32 MessageBox.Show("错误次数过多,程序即将退出!"); 33 Application.Exit(); 34 35 MessageBox.Show("登录失败"); 36 } 37 }
//字体滚动
1 private void button1_Click(object sender, EventArgs e) 2 { 3 string str = textBox1.Text; 4 char first = str[0];//取第一个字符 char类型 5 string 剩下 = str.Substring(1);//取剩下的部分 1到 最后一个部分 6 textBox1.Text = 剩下 + first; 7 8 }
//四则运算器
1 private void btnResult_Click(object sender, EventArgs e) 2 { 3 string str1 = txtNumber1.Text; 4 string str2 = txtNumber2.Text; 5 int i1 = Convert.ToInt32(str1); 6 int i2 = Convert.ToInt32(str2); 7 int result; 8 switch (cb操作符.SelectedIndex) 9 { 10 case 0://+ 11 result = i1 + i2; 12 break; 13 case 1://- 14 result = i1 - i2; 15 break; 16 case 2://* 17 result = i1 * i2; 18 break; 19 case 3:// / 20 if (i2 == 0) 21 { 22 MessageBox.Show("除数不能为零!"); 23 return; 24 } 25 result = i1 / i2; 26 break; 27 default://防患于未然 28 throw new Exception("未知的运算符");//抛异常 29 30 } 31 txtResult.Text=Convert.ToString(result); 32 }
//TextBox_Test
1 private void button1_Click(object sender, EventArgs e) 2 { 3 textBox4.AppendText(DateTime.Now.ToString()+"\n"); 4 }
//Email帐号分解 主机+域名
1 private void button1_Click(object sender, EventArgs e) 2 { 3 string email = textBox1.Text; 4 string[] strs = email.Split('@'); 5 if (strs.Length != 2) 6 { 7 MessageBox.Show("格式错误"); 8 return; 9 } 10 textBox2.Text = strs[0]; 11 textBox3.Text = strs[1]; 12 }