7简单C#代码整理

1、新建控件（newbutton）设置 click 事件，以及控件大小和位置 private void button1_Click(object sender, EventArgs e) { button1.Text = "clicked"; Button newbutton = new Button(); newbutton.Text = "new button"; newbutton.Click += new EventHandler(newbutton_click); newbutton.Size = new System.Drawing.Size(400, 400); newbutton.Location = new System.Drawing.Point(0, 30); Controls.Add(newbutton ); } private void newbutton_click(object sender, EventArgs e) { ((Button)sender ).Text="clicked"; }
InitializeComponent(); }
private void button1_Click(object sender, EventArgs e) {
string ConnectionString = @" server =MA-PC\SQLEXPRESS; integrated security=sspi; database=登陆 "; string sql = "insert into 登陆values('" + textBox1.Text.Trim() + "','" + textBox2.Text.Trim() + "')"; SqlConnection con = new SqlConnection(ConnectionString); con.Open(); SqlCommand cmd = new SqlCommand(sql, con); if (textBox2.Text.Trim() == "" || textBox3.Text.Trim() == "") {
try {
if (textBox2.Text.Trim() == textBox3.Text.Trim()) { cmd.ExecuteNonQuery(); MessageBox.Show("恭喜您注册成功\n请牢记您的密码", " 提示"); } else {
MessageBox.Show("两次输入密码不一致!请重新输入", "提示"); } } catch (SqlException) { MessageBox.Show("用户名已存在！", "提示"); } con.Close(); } } private void Form3_Load(object sender, EventArgs e) { MessageBox.Show("欢迎您的注册\n提示：\n用户名与密码不为空且长度小于","提示"); } private void button2_Click(object sender, EventArgs e) { this.Close(); } } } 6、添加（数据库） private void buttonAdd_Click(object sender, EventArgs e) { string ConnectionString = @" server =ACER-PC; integrated security=sspi; database=工资 "; string sql = "insert into 员工 values('"+ textBox1.Text.Trim() + "'," + Convert.ToInt32(textBox4.Text.Trim()) + ")"; SqlConnection con = new SqlConnection(ConnectionString); con.Open(); SqlCommand cmd = new SqlCommand(sql, con); cmd.ExecuteNonQuery(); con.Close();
4、登陆界面设计（数据库） using System; using System.Collections.Generic; using ponentModel; using System.Data; using System.Drawing; using System.Text; using System.Windows.Forms; using System.Data.SqlClient;
namespace WindowsApplication3 {
public partial class Form1 : Form {
public Form1() {
InitializeComponent(); //设置label的背景颜色为透明
label1.BackColor = Color.Transparent; label2.BackColor = Color.Transparent; string connString = @" server =MA-PC\SQLEXPRESS; integrated security=sspi; database=登陆 "; //从表memary中提取数据实现记住密码 SqlConnection con = new SqlConnection(connString); string sql = "select name from memary "; con.Open(); SqlCommand cmd = new SqlCommand(sql, con); string ming = cmd.ExecuteScalar().ToString().Trim(); textBox1.Text = ming; } private void button1_Click(object sender, EventArgs e) { string connString = @" server =MA-PC\SQLEXPRESS; integrated security=sspi; database=登陆 "; SqlConnection con = new SqlConnection(connString); string sql = "select [key] from 登陆 where name='"+textBox1.Text.ToString()+"'"; con.Open(); SqlCommand cmd = new SqlCommand(sql, con); try {
3、messagebox 对话框 private void button1_Click(object sender, EventArgs e) { if (MessageBox.Show("确定？", "提示", MessageBoxButtons.OKCancel) == DialogResult.OK) button1.Text = "123"; }
} Form2 f1 = new Form2(); f1.Show(); } else { MessageBox.Show("密码错误！请重新输入", "提示"); } con.Close(); } catch (System.NullReferenceException ) { MessageBox.Show("用户名不存在，请重新输入" ,"错误提示"); } } private void button2_Click(object sender, EventArgs e) { Form3 f = new Form3(); f.Show(); } private void button3_Click(object sender, EventArgs e) { Application.Exit(); } //设置button鼠标移入和移除的颜色 private void button1_MouseEnter(object sender, EventArgs e) { button1.ForeColor = Color.Blue; } private void button1_MouseLeave(object sender, EventArgs e) { button1.ForeColor = Color.Black; } private void button3_MouseEnter(object sender, EventArgs e) { button3.ForeColor = Color.Blue; } private void button3_MouseLeave(object sender, EventArgs e) { button3.ForeColor = Color.Black; } private void button2_MouseEnter(object sender, EventArgs e) { button2.ForeColor = Color.Blue;
string mima = cmd.ExecuteScalar().ToString().Trim(); //使表memary中的数据实时更新为登陆数据（表memary中数据有且只有一个）