打印：

打印对话框：printdialog

页面设置：pagesetupdialog

这两个对话框都需要通过设置printdocument来指定打印对象

printdocument：打印对象，必须要有，一块画板，用于打印机与打印内容之间中转，打印机打印的是printdoment

printDocument1_PrintPage:事件，每打印一页之前触发，用于给printdocument指定打印内容

通过画板把内容画到打印对象的页上：

System.Drawing.Font f = new System.Drawing.Font("宋体",12);

e.Graphics.DrawString(textBox1.Text,f,System.Drawing.Brushes.Aqua,5,5);

最后打印： 打印对话框那，如果打印对话框返回确定打印，就执行printdocument.print();

 

看一下打印界面

 

 

下面是打印界面的代码 （点击小加号打开）

 

using System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Data.SqlClient;using System.Drawing;using System.Linq;using System.Text;using System.Threading.Tasks;using System.Windows.Forms;namespace WindowsFormsApplication1{    public partial class Form1 : Form    {        public Form1()        {            InitializeComponent();        }        private void button1_Click(object sender, EventArgs e)        {            string username = textBox1.Text;            string upass = textBox2.Text;            //连接数据库            SqlConnection conn = new SqlConnection("server=.;database=data1220;user=sa;pwd=123");            conn.Open();            //执行语句            SqlCommand cmd = conn.CreateCommand();            cmd.CommandText = "select * from users where uname='" + username + "'and upass='" + upass + "'";            SqlDataReader dr = cmd.ExecuteReader();            if (dr.Read())            {                //MessageBox.Show(dr["uname"].ToString());                MessageBox.Show("登陆成功");            }            else            {                MessageBox.Show("登录失败");            }            conn.Close();        }        private void button2_Click(object sender, EventArgs e)        {            //添加数据到数据库            string username = textBox1.Text;            string upass = textBox2.Text;            //连接数据库            SqlConnection conn = new SqlConnection("server=.;database=data1220;user=sa;pwd=123");            conn.Open();            SqlCommand cmd = conn.CreateCommand();            cmd.CommandText = "insert into users values ('" + username + "'," + upass + ") ";            int count = cmd.ExecuteNonQuery();//增删改            if (count > 0)            {                MessageBox.Show("添加成功");            }            else            {                MessageBox.Show("添加失败");            }            conn.Close();        }        private void button3_Click(object sender, EventArgs e)        {            string code = textBox3.Text;            string uname = textBox1.Text;            string upass = textBox2.Text;            //连接数据库            SqlConnection conn = new SqlConnection("server=.;database=data1220;user=sa;pwd=123");            conn.Open();            SqlCommand cmd = conn.CreateCommand();            cmd.CommandText = "update users set uname='" + uname + "',upass='" + upass + "'where code=" + code;            int count = cmd.ExecuteNonQuery();            if (count > 0)            {                MessageBox.Show("修改成功");            }            else            {                MessageBox.Show("修改失败");            }            conn.Close();        }        private void button4_Click(object sender, EventArgs e)        {            string code = textBox3.Text;            //连接数据库            SqlConnection conn = new SqlConnection("server=.;database=data1220;user=sa;pwd=123");            conn.Open();            SqlCommand cmd = conn.CreateCommand();            cmd.CommandText = "delete from user where code=" + code;            cmd.ExecuteNonQuery();            conn.Close();        }    }}