C#实现QQ截图功能及相关问题

private static ScreenBody screenBody=null;

private ScreenBody(){InitializeComponent();}

private static ScreenBody GetSingle(){if(screenBody==null){screenBody=new ScreenBody();}return screenBody;}

private void btnCutter_Click(object sender,EventArgs e){ //新建一个和屏幕大小相同的图片img 也可以用BitMapimage img=new Bitmap(Screen.AllScreens[0].Bounds.Width,Screen.AllScreens[0].Bounds.Height);//创建一个画板 让我们可以在画板上画图 大小和屏幕大小一样大Graphics g=Graphics.FromImage(img); //将屏幕图片拷贝到空白图片imgg.CopyFromScreen(new Point(0,0),new Point(0,0),Screen.AllScreens[0].Bounds.Size);//创建截图窗体ScreenBody body=ScreenBody.GetSingle();//指示窗体的背景图片为屏幕图片body.BackGroundImage=img;body.ShowDialog();}

private bool CatchStart;//判断鼠标是否按下private bool CatchFinished;//判断矩形是否绘制完成private Point DownPoint;//鼠标按下的点private Image baseMap;//最基本的图片private Rectangle CatchRectangle;  

 private void ScreenBody_MouseDown(object sender, MouseEventArgs e)  {   //鼠标左键按下就是开始画图，也就是截图   if (e.Button == MouseButtons.Left)   {    if (CatchStart == false)    {     CatchStart = true;     //保存此时的坐标     DownPoint = new Point(e.X, e.Y);    }   }  }

 private void ScreenBody_MouseMove(object sender, MouseEventArgs e)  {   //确保截图开始   if (CatchStart)   {    //新建一个图片，让它与屏幕图片相同    Bitmap copyBmp = (Bitmap)baseMap.Clone();    //鼠标按下时的坐标    Point newPoint = new Point(DownPoint.X, DownPoint.Y);    //新建画板和画笔    Graphics g = Graphics.FromImage(copyBmp);    Pen p = new Pen(Color.Azure, 1);//画笔的颜色为azure 宽度为1    //获取矩形的长度     int width = Math.Abs(e.X - DownPoint.Y);    int height = Math.Abs(e.Y - DownPoint.Y);    if (e.X < DownPoint.X)    {     newPoint.X = e.X;    }    if (e.Y < DownPoint.Y)    {     newPoint.Y = e.Y;    }    CatchRectangle = new Rectangle(newPoint, new Size(width, height));    g.DrawRectangle(p, CatchRectangle);    //释放目前的画板    g.Dispose();    p.Dispose();    //从当前窗体创建新的画板    Graphics g1 = this.CreateGraphics();    //将刚刚所画的图片画到截图窗体上去    //为什么不直接在当前窗体画图呢？？？    //如果直接解决将矩形画在窗体上，会造成图片抖动而且有多个矩形    //这样实现也属于二次缓冲技术    g1.DrawImage(copyBmp, new Point(0, 0));    g1.Dispose();    //释放拷贝图片 防止内存被大量的消耗    copyBmp.Dispose();   }

 /// <summary>  /// 鼠标左键弹起事件  /// </summary>  /// <param name="sender"></param>  /// <param name="e"></param>  private void ScreenBody_MouseUp(object sender, MouseEventArgs e)  {   if (e.Button == MouseButtons.Left)   {    //如果截图已经开始，鼠标左键弹起设置截图完成    if (CatchStart)    {     CatchStart = false;     CatchFinished = true;    }   }  }

 private void ScreenBody_MouseDoubleClick(object sender, MouseEventArgs e)  {   if (e.Button==MouseButtons.Left&&CatchFinished)   {    //新建一个矩形大小相同的空白图片    Bitmap CatcheBmp = new Bitmap(CatchRectangle.Width, CatchRectangle.Height);    Graphics g = Graphics.FromImage(CatcheBmp); ;       //把basemap中指定的部分按照指定大小画到空白图片上    //CatchRectangle指定的baseMap中指定的部分    //第二个参数指定绘制到空白图片的位置和大小    //画完后CatchedBmp不再是空白图片，而是具有与截取的图片一样的内容    g.DrawImage(baseMap, new Rectangle(0, 0, CatchRectangle.Width, CatchRectangle.Height));    //将图片保存到剪切板中    Clipboard.SetImage(CatcheBmp);    g.Dispose();    CatchFinished = false;    this.BackgroundImage = baseMap;    CatcheBmp.Dispose();    this.DialogResult = DialogResult.OK;    this.Close();   }  }

/// <summary>  /// 鼠标右键点击结束截图  /// </summary>  /// <param name="sender"></param>  /// <param name="e"></param>  private void ScreenBody_MouseClick(object sender, MouseEventArgs e)  {   if (e.Button == MouseButtons.Right)   {    this.DialogResult = DialogResult.OK;    this.Close();   }  }

[FlagsAttribute] public enum KeyModifiers {  None = 0,  Alt = 1,  Ctrl = 2,  Shift = 4,  WindowsKey = 8 }

 //在C#中引用命名空间System.Runtime.InteropServices;来加载非托管类user32.dll  /*  * RegisterHotKey函数原型及说明：  * BOOL RegisterHotKey(  * HWND hWnd,   // window to receive hot-key notification  * int id,   // identifier of hot key  * UINT fsModifiers, // key-modifier flags  * UINT vk   // virtual-key code);  * 参数 id为你自己定义的一个ID值  * 对一个线程来讲其值必需在0x0000 - 0xBFFF范围之内,十进制为0~49151  * 对DLL来讲其值必需在0xC000 - 0xFFFF 范围之内,十进制为49152~65535  * 在同一进程内该值必须唯一参数 fsModifiers指明与热键联合使用按键  * 可取值为：MOD_ALT MOD_CONTROL MOD_WIN MOD_SHIFT参数，或数字0为无，1为Alt,2为Control，4为Shift，8为Windows  * vk指明热键的虚拟键码  */  [System.Runtime.InteropServices.DllImport("user32.dll")] //申明API函数  public static extern bool RegisterHotKey(   IntPtr hWnd, // handle to window   int id, // hot key identifier   uint fsModifiers, // key-modifier options   Keys vk // virtual-key code  );  [System.Runtime.InteropServices.DllImport("user32.dll")] //申明API函数  public static extern bool UnregisterHotKey(   IntPtr hWnd, // handle to window   int id // hot key identifier  );

 private void Form1_Load(object sender, EventArgs e)  {   uint ctrlHotKey = (uint)(KeyModifiers.Alt | KeyModifiers.Ctrl);   // 注册热键为Alt+Ctrl+C, "100"为唯一标识热键   RegisterHotKey(Handle, 100, ctrlHotKey, Keys.A);  }  //热键按下执行的方法  private void GlobalKeyProcess()  {   this.WindowState = FormWindowState.Minimized;   //窗口最小化需要一定的时间 使用线程   Thread.Sleep(200);   btnCutter.PerformClick();  }  protected override void WndProc(ref Message m)  {   //如果m.Msg的值为0x0312那么表示用户按下了热键   const int WM_HOTKEY = 0x0312;   switch (m.Msg)   {    case WM_HOTKEY:     if (m.WParam.ToString()=="100")     {      GlobalKeyProcess();     }     break;    default:     break;   }   base.WndProc(ref m);  }  private void Form1_FormClosing(object sender, FormClosingEventArgs e)  {   // 卸载热键   UnregisterHotKey(Handle, 100);  }