简单截图软件实现原理

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;
using System.Drawing.Drawing2D;

namespace jietu
{
    public partial class benginok : Form
    {
        public benginok()
        {
            InitializeComponent();
        }

        private void button2_Click(object sender, EventArgs e)
        {
            Application.Exit();
        }

        private void buttok_Click(object sender, EventArgs e)
        {   //隐藏窗体；
            this.Hide();
            //启动定时器，1.5秒后开始截图，以便于隐藏窗体。
            timer1.Start();
           
        }

        private void timer1_Tick(object sender, EventArgs e)
        {
            //停止定时器；
            timer1.Stop();
            Bitmap bit = new Bitmap(System.Windows.Forms.Screen.PrimaryScreen.Bounds.Width, System.Windows.Forms.Screen.PrimaryScreen.Bounds.Height);
            Graphics g = Graphics.FromImage(bit);
            g.CopyFromScreen(new Point(0, 0), new Point(0, 0), bit.Size);

            SaveFileDialog saveFileDialog = new SaveFileDialog();
            saveFileDialog.Filter = "bmp|*.bmp|jpg|*.jpg|gif|*.gif";
            if (saveFileDialog.ShowDialog() != DialogResult.Cancel)
            {
                bit.Save(saveFileDialog.FileName);
            }
            g.Dispose();
            this.Visible = true;
           
        }
    }
}