简单截图功能实现

主窗体上一个截图按钮一个富文本框。点击截图按钮可以进行截图操作

代码如下：

public partial class MainFrm : Form
    {
        public MainFrm)
        {
            InitializeComponent);        
        }

        private void btnCatch_Clickobject sender, EventArgs e)
        {
            this.Hide);//隐藏当前窗体
            System.Threading.Thread.Sleep500);//让线程睡眠一段时间，窗体消失需要一点时间
            ScrenFrm CatchForm = new ScrenFrm);
            Bitmap CatchBmp = new BitmapScreen.PrimaryScreen.Bounds.Width, Screen.PrimaryScreen.Bounds.Height);//新建一个和屏幕大小相同的图片　　　　
            Graphics g = Graphics.FromImageCatchBmp);
            g.CopyFromScreennew Point0, 0), new Point0, 0), new SizeScreen.AllScreens[0].Bounds.Width, Screen.AllScreens[0].Bounds.Height));//保存全屏图片
            CatchForm.BackgroundImage = CatchBmp;//将Catch窗体的背景设为全屏时的图片
            if CatchForm.ShowDialog) == DialogResult.OK)
            {//如果Catch窗体结束,就将剪贴板中的图片放到信息发送框中
                IDataObject iData = Clipboard.GetDataObject);
                DataFormats.Format myFormat = DataFormats.GetFormatDataFormats.Bitmap);
                if iData.GetDataPresentDataFormats.Bitmap))
                {
                    richTextBox1.PastemyFormat);
                    Clipboard.Clear);//清除剪贴板中的对象
                }
                this.Show);//重新显示窗体
            }
        }
    }

弹出窗体代码如下：

 public partial class ScrenFrm : Form
    {
        /// <summary>
        /// Required designer variable.
        /// </summary>
        private System.ComponentModel.IContainer components = null;


        /// <summary>
        /// Clean up any resources being used.
        /// </summary>
        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
        protected override void Disposebool disposing)
        {
            if disposing && components != null))
            {
                components.Dispose);
            }
            base.Disposedisposing);
        }


        #region Windows Form Designer generated code


        /// <summary>
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// </summary>
        private void InitializeComponent)
        {
            this.SuspendLayout);
            // 
            // ScrenFrm
            // 
            this.AutoScaleDimensions = new System.Drawing.SizeF6F, 12F);
            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
            this.ClientSize = new System.Drawing.Size441, 315);
            this.DoubleBuffered = true;
            this.FormBorderStyle = System.Windows.Forms.FormBorderStyle.None;
            this.Name = "ScrenFrm";
            this.Text = "截图";
            this.WindowState = System.Windows.Forms.FormWindowState.Maximized;
            this.Load += new System.EventHandlerthis.截图_Load);
            this.MouseClick += new System.Windows.Forms.MouseEventHandlerthis.截图_MouseClick);
            this.MouseDoubleClick += new System.Windows.Forms.MouseEventHandlerthis.截图_MouseDoubleClick);
            this.MouseDown += new System.Windows.Forms.MouseEventHandlerthis.截图_MouseDown);
            this.MouseMove += new System.Windows.Forms.MouseEventHandlerthis.截图_MouseMove);
            this.MouseUp += new System.Windows.Forms.MouseEventHandlerthis.截图_MouseUp);
            this.ResumeLayoutfalse);


        }


        #endregion
        
        public ScrenFrm)
        {
            InitializeComponent);
        }


        private Point downPiont = Point.Empty;//记录鼠标摁下的点
        private bool catchFinished = false;//用来表示截图是否完成
        private bool catchStart = false;    //截取开始
        private Bitmap originBitmap;       //用来保存原始图像
        private Rectangle catchRect;       //用来保存存取的矩形


        private void 截图_Loadobject sender, EventArgs e)
        {
          originBitmap= new Bitmapthis.BackgroundImage);//BackgroundImage为全屏图片，我们另用变量来保存全屏图片
        }


        private void 截图_MouseClickobject sender, MouseEventArgs e)
        {
            if e.Button == MouseButtons.Right)
            {
                this.DialogResult = DialogResult.OK;
                this.Close);
            }
        }


        private void 截图_MouseDownobject sender, MouseEventArgs e)
        {
            if e.Button == MouseButtons.Left)
            {
                if !catchStart)
                { catchStart = true;
                downPiont = new Pointe.X, e.Y);
                }
            }
        }


        private void 截图_MouseMoveobject sender, MouseEventArgs e)
        {
            if catchStart)
            {
                Bitmap destBitmap =Bitmap)originBitmap.Clone);
                Point newPoint = new Pointe.X,e.Y);
                Graphics g = Graphics.FromImagedestBitmap);//在刚才新建的图片上新建一个画板
                Pen p = new PenColor.Blue, 1);
                int width = Math.Abse.X - downPiont.X), height = Math.Abse.Y - downPiont.Y);//获取矩形的长和宽              
                catchRect = new RectanglenewPoint.X < downPiont.X ? newPoint.X : downPiont.X, newPoint.Y < downPiont.Y ? newPoint.Y : downPiont.Y, width, height);//保存矩形
                g.DrawRectanglep, catchRect);//将矩形画在这个画板上
                g.Dispose);//释放目前的这个画板
                p.Dispose);
                Graphics g1 = this.CreateGraphics);//重新新建一个Graphics类
                //如果之前那个画板不释放，而直接g=this.CreateGraphics)这样的话无法释放掉第一次创建的g,因为只是把地址转到新的g了．如同string一样
                g1 = this.CreateGraphics);//在整个全屏窗体上新建画板
                g1.DrawImagedestBitmap, new Point0, 0));//将刚才所画的图片画到这个窗体上
                //这个也可以属于二次缓冲技术，如果直接将矩形画在窗体上，会造成图片抖动并且会有无数个矩形．
                g1.Dispose);
                destBitmap.Dispose);//要及时释放，不然内存将会被大量消耗
            }
        }


        private void 截图_MouseUpobject sender, MouseEventArgs e)
        {
            if e.Button == MouseButtons.Left)
            {
                if catchStart)
                {
                    catchStart = false;
                    catchFinished = true;
                }
            }
        }


        private void 截图_MouseDoubleClickobject sender, MouseEventArgs e)
        {
            if e.Button == MouseButtons.Left && catchFinished)
            {
                if catchRect.Containsnew Pointe.X, e.Y)))
                {
                    Bitmap CatchedBmp = new BitmapcatchRect.Width, catchRect.Height);//新建一个于矩形等大的空白图片
                    Graphics g = Graphics.FromImageCatchedBmp);
                    g.DrawImageoriginBitmap, new Rectangle0, 0, catchRect.Width, catchRect.Height), catchRect, GraphicsUnit.Pixel);
                    //把orginBmp中的指定部分按照指定大小画在画板上
                    Clipboard.SetImageCatchedBmp);//将图片保存到剪贴板
                    g.Dispose);
                    catchFinished = false;
                    CatchedBmp.Dispose);
                    this.DialogResult = DialogResult.OK;
                    this.Close);
                }
            }
        } 
    }