c# winform连接sql server实现跳转登录页面简单实例
一个简单的登录页面
private void NewMethod()
{
//获取文本框中的值
username = this.textBox1.Text.Trim();
userpassword = this.textBox2.Text.Trim();
if (username.Equals("") || userpassword.Equals(""))//用户名或密码为空
{
MessageBox.Show("用户名或密码不能为空");
return;
}
else//用户名或密码不为空
{
//到数据库中验证
SqlConnection mycon = new SqlConnection(@"Server=服务器名称;Database=数据库名;user id=用户名;pwd=密码");
mycon.Open(); //建立连接
SqlCommand com = new SqlCommand();
com.Connection = mycon;
com.CommandType = CommandType.Text;
com.CommandText = "select * from [表名] where username='" + this.textBox1.Text + "'and userpassword='" + this.textBox2.Text + "'";
SqlDataReader dr = com.ExecuteReader(CommandBehavior.CloseConnection);//执行SQL语句
//CommandBehavior.CloseConnection 断开链接
if (dr.Read()) //判断
{
username = textBox1.Text;
userpassword = textBox2.Text;
//一旦连接成功了就弹出窗口
MessageBox.Show("登录成功!", "登录提示", MessageBoxButtons.OK);
}
else
{
//信息错误,判断条件不成立
MessageBox.Show("密码错误", "登录提示", MessageBoxButtons.OK, MessageBoxIcon.Error);
return;
}
mycon.Close(); //关闭链接
}
Form f2 = new FormMain(); //跳转
this.Hide();
f2.ShowDialog();
this.Dispose();
}