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;
using System.Drawing.Drawing2D;
using System.Drawing.Imaging;

namespace SolidBrush对象
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            Graphics ghs = this.CreateGraphics();//创建Graphics对象
            Brush mybs = new SolidBrush(Color.Red);
            Rectangle rt = new Rectangle(10, 10, 20, 20);
            ghs.FillRectangle(mybs, rt);

        }

        private void button2_Click(object sender, EventArgs e)
        {
            Graphics ghs = this.CreateGraphics();
            for(int i = 0; i < 6; i++)
            {
                HatchStyle hs = (HatchStyle)(2 + i);
                HatchBrush hb = new HatchBrush(hs, Color.Blue);
                Rectangle rtl = new Rectangle(10, 50 * i, 50 * i, 50);
                ghs.FillRectangle(hb, rtl);
            }
        }

        private void button3_Click(object sender, EventArgs e)
        {
            Point p1 = new Point(100, 100);
            Point p2 = new Point(200, 200);

            Graphics ghs = this.CreateGraphics();

            LinearGradientBrush lgb = new LinearGradientBrush(p1, p2, Color.Black, Color.White);
            lgb.WrapMode = WrapMode.TileFlipX;
            ghs.FillRectangle(lgb, 100, 100, 200, 200);
        }

        private void button4_Click(object sender, EventArgs e)
        {
            //横向直线
            Pen blackPen = new Pen(Color.Black, 3);
            Point p1 = new Point(10, 50);
            Point p2 = new Point(100, 50);

            Graphics ghs = this.CreateGraphics();
            ghs.DrawLine(blackPen, p1, p2);
        }

        private void button5_Click(object sender, EventArgs e)
        {
            Pen blackPen = new Pen(Color.Black, 3);
            Point p1 = new Point(10, 10);
            Point p2 = new Point(10, 100);

            Graphics ghs = this.CreateGraphics();
            ghs.DrawLine(blackPen, p1, p2);
        }

        private void button6_Click(object sender, EventArgs e)
        {
            Graphics graphics = this.CreateGraphics();
            Pen myPen = new Pen(Color.Black, 3);
            graphics.DrawEllipse(myPen, 100, 100, 50, 100);
        }

        private void button7_Click(object sender, EventArgs e)
        {
            Graphics ghs = this.CreateGraphics();
            Pen mypen = new Pen(Color.Black, 3);
            Rectangle myRectangle = new Rectangle(70, 20, 100, 60);
            ghs.DrawArc(mypen, myRectangle, 30, 120);
        }

        private void button8_Click(object sender, EventArgs e)
        {
            Graphics ghs = this.CreateGraphics();
            Pen mypen = new Pen(Color.Black, 3);
            ghs.DrawPie(mypen, 50, 50, 120, 100, 210, 120);
        }

        private void button9_Click(object sender, EventArgs e)
        {
            Graphics ghs = this.CreateGraphics();
            Pen mypen = new Pen(Color.Black, 3);
            Point p1 = new Point(80, 20);
            Point p2 = new Point(30, 40);
            Point p3 = new Point(160, 100);

            Point[] mypoints = { p1, p2, p3 };
            ghs.DrawPolygon(mypen, mypoints);
        }

        private void button10_Click(object sender, EventArgs e)
        {
            string str = "C#和肥猫";
            Font myFont = new Font("华文行楷",16);
            SolidBrush myBrush = new SolidBrush(Color.Black);
            Graphics myGraphics = this.CreateGraphics();
            myGraphics.DrawString(str,myFont,myBrush,20,20);
        }

        private void button11_Click(object sender, EventArgs e)
        {
            //绘制图形
            Image myImage = Image.FromFile("1.png");
            Graphics myGraphics = this.CreateGraphics();
            myGraphics.DrawImage(myImage, 50, 20);
        }

        private void button12_Click(object sender, EventArgs e)
        {
            //绘制公章
            int diameter = 0;//圆直径
            int brushWidth = 4;

            diameter = panel1.Width > panel1.Height ? panel1.Height : panel1.Width;

            Font Var_Font = new Font("Arial", 12, FontStyle.Bold);//字符串样式
            Font star_Font = new Font("Arial", 30, FontStyle.Regular);//星号样式
            string star_Str = "★";
            
            Rectangle rect = new Rectangle(10, 10, 160, 160);
            rect = new Rectangle(brushWidth, brushWidth, diameter - brushWidth * 2, diameter - brushWidth * 2);
            Graphics g = this.panel1.CreateGraphics();
            g.SmoothingMode = SmoothingMode.AntiAlias;//消除绘制图形的锯齿
            g.Clear(Color.White);//设置Panel1控件的背景色

            Pen myPen = new Pen(Color.Red, brushWidth);
            g.DrawEllipse(myPen, rect);

            SizeF var_Size = new SizeF(rect.Width, rect.Width);
            //画星
            var_Size = g.MeasureString(star_Str, star_Font);
            g.DrawString(star_Str, star_Font, myPen.Brush, new PointF((rect.Width / 2F) + brushWidth - var_Size.Width / 2F, rect.Height / 2F - var_Size.Width / 2F));
            //画章
            var_Size = g.MeasureString("专用章", Var_Font);
            g.DrawString("专用章", Var_Font, myPen.Brush, new PointF((rect.Width / 2F) + brushWidth - var_Size.Width / 2F, rect.Height / 2F + var_Size.Height * 2));
            
            string tempStr = "大猫科技有限公司";
            int len = tempStr.Length;
            float angle = 180 + (180 - len * 20) / 2;

            for (int i = 0; i < len; i++)
            {
                g.TranslateTransform((diameter + brushWidth / 2) / 2, (diameter + brushWidth / 2) / 2);
                g.RotateTransform(angle);
                Brush myBrush = Brushes.Red;
                g.DrawString(tempStr.Substring(i, 1), Var_Font, myBrush, 60, 0);
                g.ResetTransform();
                angle += 20;
            }

        }

        private void button13_Click(object sender, EventArgs e)
        {
            //绘制曲线
            Graphics ghs = this.CreateGraphics();
            Pen myPen = new Pen(Color.Black, 1);
            int beginX = 50;
            int beginY = 50;
            int height = 35;
            int width = 50;

            Point pointX1 = new Point(beginX, beginY);
            Point pointY1 = new Point(beginX + 210, beginY);
            Point pointX2 = new Point(beginX, beginY - 45);
            Point pointY2 = new Point(beginX, beginY + 45);

            ghs.DrawLine(myPen, pointX1, pointY1);
            ghs.DrawLine(myPen, pointX2, pointY2);
            //贝塞尔线条
            ghs.DrawBezier(myPen, beginX, beginY, beginX + 15, beginY - height, beginX + 40, beginY - height, beginX + width,beginY);

            

        }


        //缩放图片
        public bool ThumbnailCallback()
        {
            return true;
        }

        public bool GetReducedImage(double Percent,string filePath)
        {
            try
            {
                Graphics ghs = this.CreateGraphics();
                ghs.SmoothingMode = SmoothingMode.AntiAlias;//消除绘制图形的锯齿
                ghs.Clear(Color.White);//设置Panel1控件的背景色

                Bitmap bt = new Bitmap(200, 200);
                Graphics g = Graphics.FromImage(bt);
                g.Clear(Color.White);
                Image reduceImage;
                Image resourceImage = new Bitmap(@"1.jpg");
                
                Image.GetThumbnailImageAbort callb = new Image.GetThumbnailImageAbort(ThumbnailCallback);
                int ImageWidth = Convert.ToInt32(resourceImage.Width * Percent);
                int ImageHeight = Convert.ToInt32(resourceImage.Height * Percent);
                g.DrawImage(resourceImage, 0, 0, ImageWidth, ImageHeight);
                
                bt.Save(@"4.jpg", ImageFormat.Jpeg);
                reduceImage = resourceImage.GetThumbnailImage(ImageWidth, ImageHeight, callb, IntPtr.Zero);
                if(ImageWidth >ImageHeight)
                {
                    g.DrawImage(reduceImage, 0, (int)(200 - ImageHeight) / 2, ImageWidth, ImageHeight);

                }
                else
                {
                    g.DrawImage(reduceImage, 0, (int)(200 - ImageWidth) / 2, ImageWidth, ImageHeight);
                }
                g.DrawRectangle(new Pen(Color.Gray), 0, 0, 199, 199);
                
                bt.Save(@"3.jpg", ImageFormat.Jpeg);
                bt.Dispose();
                reduceImage.Dispose();

                return true;
            }
            catch(Exception e)
            {
                MessageBox.Show(e.Message);
                return false;
            }
        }
        private void button14_Click(object sender, EventArgs e)
        {
            GetReducedImage(1, "1.jpg");
        }

        private void Form1_Load(object sender, EventArgs e)
        {

        }

        //浮雕显示
        private void button16_Click(object sender, EventArgs e)
        {
            try
            {
                Image resourceImage = new Bitmap(@"1.jpg");
                Bitmap mybp = new Bitmap(resourceImage);
                
                for(int i = 0; i < mybp.Width -1;i++)
                {
                    for(int j = 0; j < mybp.Height -1;j++)
                    {
                        Color Color1 = mybp.GetPixel(i, j);
                        Color Color2 = mybp.GetPixel(i + 1, j + 1);
                        int red = Math.Abs(Color1.R - Color2.R + 128);
                        int green = Math.Abs(Color1.G - Color2.G + 128);
                        int blue = Math.Abs(Color1.B - Color2.B+128);

                        if (red > 225) red = 225;
                        if (red < 0) red = 0;
                        if (green > 225) green = 225;
                        if (green < 0) green = 0;
                        if (blue > 225) blue = 225;
                        if (blue < 0) blue = 0;

                        mybp.SetPixel(i, j, Color.FromArgb(red, green, blue));
                    }
                }
                this.BackgroundImage=mybp;

            }
            catch
            { }
        }

        //旋转图像
        private void button15_Click(object sender, EventArgs e)
        {
            Bitmap mybp = new Bitmap(200, 200);
            Image resourceImage = new Bitmap(@"1.jpg");
            Graphics g = this.panel1.CreateGraphics();
            float angle = 0;
            while(angle < 360)
            {
                TextureBrush mybrush = new TextureBrush(resourceImage);
                this.panel1.Refresh();//使工作区无效
                mybrush.RotateTransform(angle);//已制定角度旋转图像
                g.FillRectangle(mybrush, 0, 0, this.ClientRectangle.Width, this.ClientRectangle.Height);//绘制旋转后图像
                angle += 10f;
                System.Threading.Thread.Sleep(50);//使线程休眠50毫秒
            }
            
        }
    }
}