C# 实现QQ式截图功能实例代码

 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; using System.Drawing.Imaging; using ImageClassLib; namespace ImageShear { public partial class Demo: Form { public Demo() { InitializeComponent(); } #region 点击打开图像 public string strHeadImagePath; //打开图片的路径 Bitmap Bi; //定义位图对像 private void button1_Click(object sender, EventArgs e) { openFileDialog1.Filter = "*.gif|*.jpg-600|*.JPEG|*.JPEG|*.bmp|*.bmp";     //设置读取图片类型 if (openFileDialog1.ShowDialog() == DialogResult.OK) { try { strHeadImagePath = openFileDialog1.FileName; //this.Show(strHeadImagePath); Bi = new Bitmap(strHeadImagePath); //使用打开的图片路径创建位图对像 ImageCut1 IC = new ImageCut1(40, 112, this.pictureBox1.Width, this.pictureBox1.Height);   //实例化ImageCut类，四个参数据分别表示为：x、y、width、heigth，（40、112）表示pictureBox1的Lcation的坐标，（120、144）表示pictureBox1控件的宽度和高度 this.pictureBox1.Image = IC.KiCut1((Bitmap)(this.GetSelectImage(this.pictureBox1.Width, this.pictureBox1.Height)));   //（120、144）表示pictureBox1控件的宽度和高度 //this.pictureBox1.Image = (this.GetSelectImage(120, 144)); } catch (Exception ex) { MessageBox.Show("格式不对"); ex.ToString(); } } } #endregion #region 定义显示图像方法，即将打开的图像在pictureBox1控件显示 public void Show(string strHeadImagePath) { this.pictureBox1.Load(@strHeadImagePath);  // } #endregion #region 获取图像 /// 
 /// 获取指定宽度和高度的图像即使图片和pictureBox1控件一样宽和高，返回值为图片Image /// 
 ///  ///  ///  public Image GetSelectImage(int Width, int Height) { //Image initImage = this.pictureBox1.Image; Image initImage = Bi; //原图宽高均小于模版，不作处理，直接保存 if (initImage.Width <= Width && initImage.Height <= Height) { //initImage.Save(fileSaveUrl, System.Drawing.Imaging.ImageFormat.Jpeg); return initImage; } else { //原始图片的宽、高 int initWidth = initImage.Width; int initHeight = initImage.Height; //非正方型先裁剪为正方型 if (initWidth != initHeight) { //截图对象 System.Drawing.Image pickedImage = null; System.Drawing.Graphics pickedG = null; //宽大于高的横图 if (initWidth > initHeight) { //对象实例化 pickedImage = new System.Drawing.Bitmap(initHeight, initHeight); pickedG = System.Drawing.Graphics.FromImage(pickedImage); //设置质量 pickedG.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic; pickedG.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality; //定位 Rectangle fromR = new Rectangle((initWidth - initHeight) / 2, 0, initHeight, initHeight); Rectangle toR = new Rectangle(0, 0, initHeight, initHeight); //画图 pickedG.DrawImage(initImage, toR, fromR, System.Drawing.GraphicsUnit.Pixel); //重置宽 initWidth = initHeight; } //高大于宽的竖图 else { //对象实例化 pickedImage = new System.Drawing.Bitmap(initWidth, initWidth); pickedG = System.Drawing.Graphics.FromImage(pickedImage); //设置质量 pickedG.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic; pickedG.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality; //定位 Rectangle fromR = new Rectangle(0, (initHeight - initWidth) / 2, initWidth, initWidth); Rectangle toR = new Rectangle(0, 0, initWidth, initWidth); //画图 pickedG.DrawImage(initImage, toR, fromR, System.Drawing.GraphicsUnit.Pixel); //重置高 initHeight = initWidth; } initImage = (System.Drawing.Image)pickedImage.Clone(); //        //释放截图资源 pickedG.Dispose(); pickedImage.Dispose(); } return initImage; } } #endregion #region 点击button2按钮事件 private void button2_Click(object sender, EventArgs e) { this.label1.Text = "裁剪后的图片宽度："+this.pictureBox2.Width.ToString(); this.label2.Text = "裁剪后的图片高度："+this.pictureBox2.Height.ToString(); } #endregion #region 缩放、裁剪图像用到的变量 /// 
 /// /// 
 int x1;   //鼠标按下时横坐标 int y1;   //鼠标按下时纵坐标 int width; //所打开的图像的宽 int heigth; //所打开的图像的高 bool HeadImageBool = false;  // 此布尔变量用来判断pictureBox1控件是否有图片 #endregion #region 画矩形使用到的变量 Point p1;  //定义鼠标按下时的坐标点 Point p2;  //定义移动鼠标时的坐标点 Point p3;  //定义松开鼠标时的坐标点 #endregion #region 鼠标按下时发生的事件 private void pictureBox1_MouseDown(object sender, MouseEventArgs e) { this.Cursor = Cursors.Cross; this.p1 = new Point(e.X, e.Y); x1 = e.X; y1 = e.Y; if (this.pictureBox1.Image != null) { HeadImageBool = true; } else { HeadImageBool = false; } } #endregion #region 移动鼠标发生的事件 private void pictureBox1_MouseMove(object sender, MouseEventArgs e) { if (this.Cursor == Cursors.Cross) { this.p2 = new Point(e.X, e.Y); if ((p2.X - p1.X) > 0 && (p2.Y - p1.Y) > 0)   //当鼠标从左上角向开始移动时P3坐标 { this.p3 = new Point(p1.X, p1.Y); } if ((p2.X - p1.X) <0 && (p2.y - p1.y)> 0)   //当鼠标从右上角向左下方向开始移动时P3坐标 { this.p3 = new Point(p2.X, p1.Y); } if ((p2.X - p1.X) > 0 && (p2.Y - p1.Y) <0)   //当鼠标从左下角向上开始移动时P3坐标 { this.p3 = new Point(p1.X, p2.Y); } if ((p2.X - p1.X) <0 && (p2.y - p1.y) < 0)> 0 && (e.Y - y1) > 0)  //当鼠标从左上角向右下方向开始移动时发生 { IC1 = new ImageCut1(x1, y1, Math.Abs(e.X - x1), Math.Abs(e.Y - y1));  //实例化ImageCut1类 } if ((e.X - x1) <0 && (e.y - y1)> 0)  //当鼠标从右上角向左下方向开始移动时发生 { IC1 = new ImageCut1(e.X, y1, Math.Abs(e.X - x1), Math.Abs(e.Y - y1));  //实例化ImageCut1类 } if ((e.X - x1) > 0 && (e.Y - y1) <0)  //当鼠标从左下角向右上方向开始移动时发生 { IC1 = new ImageCut1(x1, e.Y, Math.Abs(e.X - x1), Math.Abs(e.Y - y1));  //实例化ImageCut1类 } if ((e.X - x1) <0 && (e.y - y1) < 0)> /// ///  ///  ///  ///  public Image GetSelectImage1(int Width, int Height) { Image initImage = this.pictureBox1.Image; //Image initImage = Bi; //原图宽高均小于模版，不作处理，直接保存 if (initImage.Width <= Width && initImage.Height <= Height) { //initImage.Save(fileSaveUrl, System.Drawing.Imaging.ImageFormat.Jpeg); return initImage; } else { //原始图片的宽、高 int initWidth = initImage.Width; int initHeight = initImage.Height; //非正方型先裁剪为正方型 if (initWidth != initHeight) { //截图对象 System.Drawing.Image pickedImage = null; System.Drawing.Graphics pickedG = null; //宽大于高的横图 if (initWidth > initHeight) { //对象实例化 pickedImage = new System.Drawing.Bitmap(initHeight, initHeight); pickedG = System.Drawing.Graphics.FromImage(pickedImage); //设置质量 pickedG.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic; pickedG.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality; //定位 Rectangle fromR = new Rectangle((initWidth - initHeight) / 2, 0, initHeight, initHeight); Rectangle toR = new Rectangle(0, 0, initHeight, initHeight); //画图 pickedG.DrawImage(initImage, toR, fromR, System.Drawing.GraphicsUnit.Pixel); //重置宽 initWidth = initHeight; } //高大于宽的竖图 else { //对象实例化 pickedImage = new System.Drawing.Bitmap(initWidth, initWidth); pickedG = System.Drawing.Graphics.FromImage(pickedImage); //设置质量 pickedG.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic; pickedG.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality; //定位 Rectangle fromR = new Rectangle(0, (initHeight - initWidth) / 2, initWidth, initWidth); Rectangle toR = new Rectangle(0, 0, initWidth, initWidth); //画图 pickedG.DrawImage(initImage, toR, fromR, System.Drawing.GraphicsUnit.Pixel); //重置高 initHeight = initWidth; } initImage = (System.Drawing.Image)pickedImage.Clone(); //        //释放截图资源 pickedG.Dispose(); pickedImage.Dispose(); } return initImage; } } #endregion #region 重新绘制pictureBox1控件，即移动鼠标画矩形 private void pictureBox1_Paint(object sender, PaintEventArgs e) { if (HeadImageBool) { Pen p = new Pen(Color.Black, 1);//画笔 p.DashStyle = System.Drawing.Drawing2D.DashStyle.Dash; //Bitmap bitmap = new Bitmap(strHeadImagePath); Bitmap bitmap = Bi; Rectangle rect = new Rectangle(p3, new Size(System.Math.Abs(p2.X - p1.X), System.Math.Abs(p2.Y - p1.Y))); e.Graphics.DrawRectangle(p, rect); } else { } } #endregion } } 

 using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Drawing; using System.Drawing.Drawing2D; using System.Drawing.Imaging; namespace ImageClassLib { public class ImageCut1 { #region 剪裁图片方法 /// 
 /// 剪裁 -- 用GDI+ /// 
 /// 原始Bitmap,即需要裁剪的图片 /// 开始坐标X /// 开始坐标Y /// 宽度 /// 高度 /// 剪裁后的Bitmap public Bitmap KiCut1(Bitmap b) { if (b == null) { return null; } int w = b.Width; int h = b.Height; if (X >= w || Y >= h) { return null; } if (X + Width > w) { Width = w - X; } if (Y + Height > h) { Height = h - Y; } try { Bitmap bmpOut = new Bitmap(Width, Height, PixelFormat.Format24bppRgb); Graphics g = Graphics.FromImage(bmpOut); // Create rectangle for displaying image. Rectangle destRect = new Rectangle(0, 0, Width, Height);    //所画的矩形正确，它指定所绘制图像的位置和大小。 将图像进行缩放以适合该矩形。 // Create rectangle for source image. Rectangle srcRect = new Rectangle(X, Y, Width, Height);   //srcRect参数指定要绘制的 image 对象的矩形部分。 将此部分进行缩放以适合 destRect 参数所指定的矩形。 g.DrawImage(b, destRect, srcRect, GraphicsUnit.Pixel); //resultG.DrawImage(initImage, new System.Drawing.Rectangle(0, 0, side, side), new System.Drawing.Rectangle(0, 0, initWidth, initHeight), System.Drawing.GraphicsUnit.Pixel); g.Dispose(); return bmpOut; } catch { return null; } } #endregion #region ImageCut1类的构造函数 public int X; public int Y; public int Width ; public int Height; /// 
 /// ImageCut1类的构造函数，ImageCut1类用来获取鼠标在pictureBox1控件所画矩形内的图像 /// 
 ///  ///  ///  ///  public ImageCut1(int x, int y, int width, int heigth) { X = x; Y = y; Width = width; Height = heigth; } #endregion } }