GDI

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
namespace _126_使用GDI绘制简单图形
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        private void btnLine_Click(object sender, EventArgs e)
        {
            //创建GDI对象
            Graphics g = this.CreateGraphics();            //new Graphics();没有构造函数
            //创建画笔对象
            Pen pen = new Pen(Brushes.Black);
            //创建两个点
            Point p1 = new Point(30, 50);
            Point p2 = new Point(250, 250);
            //开始画
            g.DrawLine(pen, p1, p2);
        }
        int i = 0;
        private void Form1_Paint(object sender, PaintEventArgs e)
        {
            i++;
            lblRefresh.Text = i.ToString();
            //创建GDI对象
            Graphics g = this.CreateGraphics();
            //创建画笔对象
            Pen pen = new Pen(Brushes.Black);
            //创建两个点
            Point p1 = new Point(30, 50);
            Point p2 = new Point(250, 250);
            //开始画
            g.DrawLine(pen, p1, p2);
        }
        private void btbRectangle_Click(object sender, EventArgs e)
        {
            Graphics g = this.CreateGraphics();
            //DrawRectangle()需要两个对象，画笔和矩形
            Pen pen = new Pen(Brushes.Red);
            Size size = new Size(80, 80);
            Rectangle rec = new Rectangle(new Point(50, 50), size);  //Rectangle rec = new Rectangle(50,50,80,80 );
            g.DrawRectangle(pen, rec);
        }
        private void btnSector_Click(object sender, EventArgs e)
        {
            Graphics g = this.CreateGraphics();
            //DrawPie()方法需要的四个参数：
            //1、画笔
            Pen pen = new Pen(Brushes.Blue);
            //2、矩形
            Size size = new Size(180, 480);
            Rectangle rec = new Rectangle(new Point(150, 150), size);
            //3、4、两个角度 startAngle,sweepAngle
            //画扇形
            g.DrawPie(pen, rec, 270, 60);
        }
        private void btnText_Click(object sender, EventArgs e)
        {
            Graphics g = this.CreateGraphics();
            //画文本
            g.DrawString("韦晓龙牛逼", new Font("宋体", 20, FontStyle.Bold), Brushes.DarkViolet, new Point(300, 300));
        }
    }
}