GDI+实例开源

来源：互联网发布：小米6 手机网络不佳编辑：程序博客网时间：2024/06/14 23:16
原帖及讨论：http://bbs.bccn.net/thread-216343-1-1.html 
本来是学c#的，但是由于喜欢web开发，所以winform学的不是怎么样，对GDI+一直是知道理论也没有什么实践，最近找了点资料，做了点东西，和大家分享分享，有什么地方做的不好，还希望大家指点……
谢谢……
开发工具：visual studio 2005
Form1.cs页面：
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
namespace WindowsApplication6
{
    public partial class Form1 : Form
    {
        private Bitmap smallBmp;
        private Bitmap bmp;  //holds original loaded image 
        private Bitmap newbmp;  //holds latest version of image 
        private bool imageStatus = false;  //indicates image is loaded 
        private int resizeLevel;  //level image magnified/reduced 
        private Point lastPoint = Point.Empty;//tracks mouse movement 
        private Point origPoint = Point.Empty;//mouse down coordinates 
        private Rectangle rectSel;//select area 
        private bool selectStatus;//true if area selected 
        public Form1()
        {
            InitializeComponent();
            panel1.MouseDown+=new MouseEventHandler(panel1_MouseDown);
            panel1.MouseUp+=new MouseEventHandler(panel1_MouseUp);
            panel1.MouseMove+=new MouseEventHandler(panel1_MouseMove);
            panel1.Paint+=new PaintEventHandler(panel1_Paint);
        }
        private void Form1_Load(object sender, EventArgs e)
        {
        }
        private void openMenuItem_Click(object sender, EventArgs e)
        {
            //load image from file 
            OpenFileDialog fd = new OpenFileDialog();
            fd.InitialDirectory = @"D:/My Documents/My Pictures";
            fd.Filter = "Image File|*.jpg;*.gif";
            if (fd.ShowDialog() == DialogResult.OK)
            {
                string fname = fd.FileName;
                using (Graphics g = panel1.CreateGraphics())
                {
                    bmp = new Bitmap(fname);
                    newbmp = bmp;
                    g.FillRectangle(Brushes.White, 0, 0, panel1.Width, panel1.Height);
                    Rectangle r = new Rectangle(0, 0, bmp.Width, bmp.Height);
                    g.DrawImage(bmp, r);
                    imageStatus = true;
                    Graphics gClear = panel2.CreateGraphics();
                    gClear.FillRectangle(Brushes.White, 0, 0, panel2.Width, panel2.Height);
                    gClear.Dispose();
                }
            }
        }
        private void mirrorMenuItem_Click(object sender, EventArgs e)
        {
            Graphics g = panel1.CreateGraphics();
            int h = newbmp.Height;
            int w = newbmp.Width;
            Point[] destPts ={
                new Point(w,0),
                new Point(0,0),
                new Point(w,h)
            };
            Bitmap tempBmp = new Bitmap(w, h);
            Graphics gr = Graphics.FromImage(tempBmp);
            gr.DrawImage(newbmp, destPts);
            g.DrawImage(tempBmp, 0, 0);
            newbmp = tempBmp;
            g.Dispose();
            gr.Dispose();
        }
        private void 翻转VToolStripMenuItem_Click(object sender, EventArgs e)
        {
            newbmp.RotateFlip(RotateFlipType.RotateNoneFlipY);
            Graphics g = panel1.CreateGraphics();
            g.DrawImage(newbmp, 0, 0);
            g.Dispose();
        }
        private void 刷屏RToolStripMenuItem_Click(object sender, EventArgs e)
        {
            panel1.Invalidate();
            panel1.Update();
            selectStatus = false;
        }
        private void panel1_Paint(object sender, PaintEventArgs e)
        {
            Graphics g = e.Graphics;
            //redraw part of current image to panel 
            if (imageStatus)
            {
                g.DrawImage(newbmp, e.ClipRectangle, e.ClipRectangle, GraphicsUnit.Pixel);
            }
            base.OnPaint(e);
        }
        private void panel1_MouseDown(object sender, MouseEventArgs e)
        {
            if (lastPoint != Point.Empty)
            {
                panel1.Invalidate(rectSel);
                panel1.Update();
            }
            lastPoint.X = e.X;
            lastPoint.Y = e.Y;
            origPoint = lastPoint;
            selectStatus = true;
        }
        private void panel1_MouseUp(object sender, MouseEventArgs e)
        {
            rectSel.X = e.X;
            if (e.X > origPoint.X)
            {
                rectSel.X = origPoint.X;
            }
            rectSel.Y = origPoint.Y;
            rectSel.Width = Math.Abs(e.X - origPoint.X) + 1;
            rectSel.Height = Math.Abs(e.Y - origPoint.Y) + 1;
            origPoint = Point.Empty;
            if (rectSel.Width < 2)
            {
                selectStatus = false;
            }
        }
        private void panel1_MouseMove(object sender, MouseEventArgs e)
        {
            if (origPoint != Point.Empty)
            {
                Rectangle r;
                Rectangle rd;
                int xop = origPoint.X;
                if (xop > lastPoint.X)
                {
                    xop = lastPoint.X;
                }
                int w = Math.Abs(origPoint.X - lastPoint.X) + 1;
                int h = lastPoint.Y - origPoint.Y + 1;
                r = new Rectangle(xop, origPoint.Y, w, h);
                xop = e.X >= origPoint.X ? origPoint.X : e.X;
                w = Math.Abs(origPoint.X - e.X);
                h = e.Y - origPoint.Y;
                rd = new Rectangle(xop, origPoint.Y, w, h);
                Graphics g = panel1.CreateGraphics();
               
                g.DrawImage(newbmp,r);
                //newbmp.MakeTransparent(); 
                g.DrawRectangle(Pens.Red, rd);
                g.Dispose();
                lastPoint.X = e.X;
                lastPoint.Y = e.Y;
            }
        }
        private void 查看cToolStripMenuItem_Click(object sender, EventArgs e)
        {
            if (selectStatus)
            {
                Graphics g = panel2.CreateGraphics();
                g.FillRectangle(Brushes.White, panel2.ClientRectangle);
                Rectangle rd = new Rectangle(0, 0, rectSel.Width, rectSel.Height);
                Bitmap temp = new Bitmap(rectSel.Width, rectSel.Height);
                Graphics gi = Graphics.FromImage(temp);
                gi.DrawImage(newbmp, rd, rectSel, GraphicsUnit.Pixel);
                smallBmp = temp;
                g.DrawImage(smallBmp, rd);
                g.Dispose();
                resizeLevel = 0;
            }
        }
        private void button1_Click(object sender, EventArgs e)
        {
            Graphics g = panel2.CreateGraphics();
            if (smallBmp != null)
            {
                resizeLevel = resizeLevel + 1;
                float fac = (float)(1.0 + (resizeLevel * .25));
                int w = (int)(smallBmp.Width * fac);
                int h = (int)(smallBmp.Height * fac);
                Rectangle rd = new Rectangle(0, 0, w, h);
                Bitmap tempBmp = new Bitmap(w, h);
                Graphics gi = Graphics.FromImage(tempBmp);
                gi.DrawImage(smallBmp, rd);
                g.DrawImage(tempBmp,rd);
                gi.Dispose();
            }
            g.Dispose();
        }
        private void button2_Click(object sender, EventArgs e)
        {
            Graphics g = panel2.CreateGraphics();
            if (smallBmp != null)
            {
                resizeLevel = (resizeLevel > -3) ? resizeLevel - 1 : resizeLevel;
                float fac = (float)(1.0 + (resizeLevel * .25));
                int w = (int)(smallBmp.Width * fac);
                int h = (int)(smallBmp.Height * fac);
                Rectangle rd = new Rectangle(0, 0, w, h);
                Bitmap tempBmp = new Bitmap(w, h);
          
              
                Graphics gi = Graphics.FromImage(tempBmp);
                g.FillRectangle(Brushes.White, panel2.ClientRectangle);
                gi.DrawImage(smallBmp, rd);
                g.DrawImage(tempBmp, rd);
           
                gi.Dispose();
                //panel2.Invalidate(); 
                //panel2.Update(); 
            }
         
            g.Dispose();
           
        }
    }
} 
Form1.Designer.cs页面
namespace WindowsApplication6
{
    partial class Form1
    {
        /// <summary> 
        /// 必需的设计器变量。 
        /// </summary> 
        private System.ComponentModel.IContainer components = null;
        /// <summary> 
        /// 清理所有正在使用的资源。 
        /// </summary> 
        /// <param name="disposing">如果应释放托管资源，为 true；否则为 false。</param> 
        protected override void Dispose(bool disposing)
        {
            if (disposing && (components != null))
            {
                components.Dispose();
            }
            base.Dispose(disposing);
        } 
        #region Windows 窗体设计器生成的代码 
        /// <summary> 
        /// 设计器支持所需的方法 - 不要 
        /// 使用代码编辑器修改此方法的内容。 
        /// </summary> 
        private void InitializeComponent()
        {
            System.ComponentModel.ComponentResourceManager resources = new System.ComponentModel.ComponentResourceManager(typeof(Form1));
            this.menuStrip1 = new System.Windows.Forms.MenuStrip();
            this.文件FToolStripMenuItem = new System.Windows.Forms.ToolStripMenuItem();
            this.openMenuItem = new System.Windows.Forms.ToolStripMenuItem();
            this.图像IToolStripMenuItem = new System.Windows.Forms.ToolStripMenuItem();
            this.mirrorMenuItem = new System.Windows.Forms.ToolStripMenuItem();
            this.屏幕ＳToolStripMenuItem = new System.Windows.Forms.ToolStripMenuItem();
            this.panel1 = new System.Windows.Forms.Panel();
            this.panel2 = new System.Windows.Forms.Panel();
            this.button1 = new System.Windows.Forms.Button();
            this.button2 = new System.Windows.Forms.Button();
            this.翻转VToolStripMenuItem = new System.Windows.Forms.ToolStripMenuItem();
            this.刷屏RToolStripMenuItem = new System.Windows.Forms.ToolStripMenuItem();
            this.查看cToolStripMenuItem = new System.Windows.Forms.ToolStripMenuItem();
            this.menuStrip1.SuspendLayout();
            this.SuspendLayout();
            //  
            // menuStrip1 
            //  
            this.menuStrip1.Items.AddRange(new System.Windows.Forms.ToolStripItem[] {
            this.文件FToolStripMenuItem,
            this.图像IToolStripMenuItem,
            this.屏幕ＳToolStripMenuItem});
            this.menuStrip1.Location = new System.Drawing.Point(0, 0);
            this.menuStrip1.Name = "menuStrip1";
            this.menuStrip1.Size = new System.Drawing.Size(655, 24);
            this.menuStrip1.TabIndex = 0;
            this.menuStrip1.Text = "menuStrip1";
            //  
            // 文件FToolStripMenuItem 
            //  
            this.文件FToolStripMenuItem.DropDownItems.AddRange(new System.Windows.Forms.ToolStripItem[] {
            this.openMenuItem});
            this.文件FToolStripMenuItem.Name = "文件FToolStripMenuItem";
            this.文件FToolStripMenuItem.Size = new System.Drawing.Size(73, 20);
            this.文件FToolStripMenuItem.Text = "文件（&F）";
            //  
            // openMenuItem 
            //  
            this.openMenuItem.Name = "openMenuItem";
            this.openMenuItem.Size = new System.Drawing.Size(114, 22);
            this.openMenuItem.Text = "打开(&O)";
            this.openMenuItem.Click += new System.EventHandler(this.openMenuItem_Click);
            //  
            // 图像IToolStripMenuItem 
            //  
            this.图像IToolStripMenuItem.DropDownItems.AddRange(new System.Windows.Forms.ToolStripItem[] {
            this.mirrorMenuItem,
            this.翻转VToolStripMenuItem,
            this.查看cToolStripMenuItem});
            this.图像IToolStripMenuItem.Name = "图像IToolStripMenuItem";
            this.图像IToolStripMenuItem.Size = new System.Drawing.Size(71, 20);
            this.图像IToolStripMenuItem.Text = "图像（&I）";
            //  
            // mirrorMenuItem 
            //  
            this.mirrorMenuItem.Name = "mirrorMenuItem";
            this.mirrorMenuItem.Size = new System.Drawing.Size(152, 22);
            this.mirrorMenuItem.Text = "镜像(&M)";
            this.mirrorMenuItem.Click += new System.EventHandler(this.mirrorMenuItem_Click);
            //  
            // 屏幕ＳToolStripMenuItem 
            //  
            this.屏幕ＳToolStripMenuItem.DropDownItems.AddRange(new System.Windows.Forms.ToolStripItem[] {
            this.刷屏RToolStripMenuItem});
            this.屏幕ＳToolStripMenuItem.Name = "屏幕ＳToolStripMenuItem";
            this.屏幕ＳToolStripMenuItem.Size = new System.Drawing.Size(73, 20);
            this.屏幕ＳToolStripMenuItem.Text = "屏幕（&S）";
            //  
            // panel1 
            //  
            this.panel1.Location = new System.Drawing.Point(12, 27);
            this.panel1.Name = "panel1";
            this.panel1.Size = new System.Drawing.Size(327, 327);
            this.panel1.TabIndex = 1;
            //  
            // panel2 
            //  
            this.panel2.Location = new System.Drawing.Point(364, 27);
            this.panel2.Name = "panel2";
            this.panel2.Size = new System.Drawing.Size(273, 262);
            this.panel2.TabIndex = 2;
            //  
            // button1 
            //  
            this.button1.BackColor = System.Drawing.Color.FromArgb(((int)(((byte)(255)))), ((int)(((byte)(224)))), ((int)(((byte)(192)))));
            this.button1.FlatStyle = System.Windows.Forms.FlatStyle.Flat;
            this.button1.Font = new System.Drawing.Font("宋体", 15F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(134)));
            this.button1.Location = new System.Drawing.Point(437, 315);
            this.button1.Name = "button1";
            this.button1.Size = new System.Drawing.Size(39, 23);
            this.button1.TabIndex = 3;
            this.button1.Text = "+";
            this.button1.UseVisualStyleBackColor = false;
            this.button1.Click += new System.EventHandler(this.button1_Click);
            //  
            // button2 
            //  
            this.button2.BackColor = System.Drawing.Color.FromArgb(((int)(((byte)(255)))), ((int)(((byte)(224)))), ((int)(((byte)(192)))));
            this.button2.FlatStyle = System.Windows.Forms.FlatStyle.Flat;
            this.button2.Font = new System.Drawing.Font("宋体", 15F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(134)));
            this.button2.Location = new System.Drawing.Point(539, 315);
            this.button2.Name = "button2";
            this.button2.Size = new System.Drawing.Size(39, 23);
            this.button2.TabIndex = 4;
            this.button2.Text = "-";
            this.button2.UseVisualStyleBackColor = false;
            this.button2.Click += new System.EventHandler(this.button2_Click);
            //  
            // 翻转VToolStripMenuItem 
            //  
            this.翻转VToolStripMenuItem.Name = "翻转VToolStripMenuItem";
            this.翻转VToolStripMenuItem.Size = new System.Drawing.Size(152, 22);
            this.翻转VToolStripMenuItem.Text = "翻转(&V)";
            this.翻转VToolStripMenuItem.Click += new System.EventHandler(this.翻转VToolStripMenuItem_Click);
            //  
            // 刷屏RToolStripMenuItem 
            //  
            this.刷屏RToolStripMenuItem.Name = "刷屏RToolStripMenuItem";
            this.刷屏RToolStripMenuItem.Size = new System.Drawing.Size(152, 22);
            this.刷屏RToolStripMenuItem.Text = "刷屏（&R）";
            this.刷屏RToolStripMenuItem.Click += new System.EventHandler(this.刷屏RToolStripMenuItem_Click);
            //  
            // 查看cToolStripMenuItem 
            //  
            this.查看cToolStripMenuItem.Name = "查看cToolStripMenuItem";
            this.查看cToolStripMenuItem.Size = new System.Drawing.Size(152, 22);
            this.查看cToolStripMenuItem.Text = "查看(&c)";
            this.查看cToolStripMenuItem.Click += new System.EventHandler(this.查看cToolStripMenuItem_Click);
            //  
            // Form1 
            //  
            this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 12F);
            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
            this.ClientSize = new System.Drawing.Size(655, 375);
            this.Controls.Add(this.button2);
            this.Controls.Add(this.button1);
            this.Controls.Add(this.panel2);
            this.Controls.Add(this.panel1);
            this.Controls.Add(this.menuStrip1);
            this.Icon = ((System.Drawing.Icon)(resources.GetObject("$this.Icon")));
            this.MainMenuStrip = this.menuStrip1;
            this.Name = "Form1";
            this.Text = "Form1";
            this.Load += new System.EventHandler(this.Form1_Load);
            this.menuStrip1.ResumeLayout(false);
            this.menuStrip1.PerformLayout();
            this.ResumeLayout(false);
            this.PerformLayout();
        } 
        #endregion 
        private System.Windows.Forms.MenuStrip menuStrip1;
        private System.Windows.Forms.ToolStripMenuItem 文件FToolStripMenuItem;
        private System.Windows.Forms.ToolStripMenuItem 图像IToolStripMenuItem;
        private System.Windows.Forms.ToolStripMenuItem 屏幕ＳToolStripMenuItem;
        private System.Windows.Forms.ToolStripMenuItem openMenuItem;
        private System.Windows.Forms.Panel panel1;
        private System.Windows.Forms.Panel panel2;
        private System.Windows.Forms.Button button1;
        private System.Windows.Forms.Button button2;
        private System.Windows.Forms.ToolStripMenuItem mirrorMenuItem;
        private System.Windows.Forms.ToolStripMenuItem 翻转VToolStripMenuItem;
        private System.Windows.Forms.ToolStripMenuItem 刷屏RToolStripMenuItem;
        private System.Windows.Forms.ToolStripMenuItem 查看cToolStripMenuItem;
    }
} 
Progrem.cs页面
using System;
using System.Collections.Generic;
using System.Windows.Forms;
namespace WindowsApplication6
{
    static class Program
    {
        /// <summary> 
        /// 应用程序的主入口点。 
        /// </summary> 
        [STAThread]
        static void Main()
        {
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);
            Application.Run(new Form1());
        }
    }
} 