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_Click(object sender, EventArgs e)
{
this.Hide();//隐藏当前窗体
System.Threading.Thread.Sleep(500);//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 Bitmap(Screen.PrimaryScreen.Bounds.Width, Screen.PrimaryScreen.Bounds.Height);//新建一个和屏幕大小相同的图片
Graphics g = Graphics.FromImage(CatchBmp);
g.CopyFromScreen(new Point(0, 0), new Point(0, 0), new Size(Screen.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.GetFormat(DataFormats.Bitmap);
if (iData.GetDataPresent(DataFormats.Bitmap))
{
richTextBox1.Paste(myFormat);
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 Dispose(bool disposing)
{
if (disposing && (components != null))
{
components.Dispose();
}
base.Dispose(disposing);
}
#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.SizeF(6F, 12F);
this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
this.ClientSize = new System.Drawing.Size(441, 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.EventHandler(this.截图_Load);
this.MouseClick += new System.Windows.Forms.MouseEventHandler(this.截图_MouseClick);
this.MouseDoubleClick += new System.Windows.Forms.MouseEventHandler(this.截图_MouseDoubleClick);
this.MouseDown += new System.Windows.Forms.MouseEventHandler(this.截图_MouseDown);
this.MouseMove += new System.Windows.Forms.MouseEventHandler(this.截图_MouseMove);
this.MouseUp += new System.Windows.Forms.MouseEventHandler(this.截图_MouseUp);
this.ResumeLayout(false);
}
#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_Load(object sender, EventArgs e)
{
originBitmap= new Bitmap(this.BackgroundImage);//BackgroundImage为全屏图片，我们另用变量来保存全屏图片
}
private void 截图_MouseClick(object sender, MouseEventArgs e)
{
if (e.Button == MouseButtons.Right)
{
this.DialogResult = DialogResult.OK;
this.Close();
}
}
private void 截图_MouseDown(object sender, MouseEventArgs e)
{
if (e.Button == MouseButtons.Left)
{
if (!catchStart)
{ catchStart = true;
downPiont = new Point(e.X, e.Y);
}
}
}
private void 截图_MouseMove(object sender, MouseEventArgs e)
{
if (catchStart)
{
Bitmap destBitmap =(Bitmap)originBitmap.Clone();
Point newPoint = new Point(e.X,e.Y);
Graphics g = Graphics.FromImage(destBitmap);//在刚才新建的图片上新建一个画板
Pen p = new Pen(Color.Blue, 1);
int width = Math.Abs(e.X - downPiont.X), height = Math.Abs(e.Y - downPiont.Y);//获取矩形的长和宽
catchRect = new Rectangle(newPoint.X < downPiont.X ? newPoint.X : downPiont.X, newPoint.Y < downPiont.Y ? newPoint.Y : downPiont.Y, width, height);//保存矩形
g.DrawRectangle(p, 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.DrawImage(destBitmap, new Point(0, 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_MouseUp(object sender, MouseEventArgs e)
{
if (e.Button == MouseButtons.Left)
{
if (catchStart)
{
catchStart = false;
catchFinished = true;
}
}
}
private void 截图_MouseDoubleClick(object sender, MouseEventArgs e)
{
if (e.Button == MouseButtons.Left && catchFinished)
{
if (catchRect.Contains(new Point(e.X, e.Y)))
{
Bitmap CatchedBmp = new Bitmap(catchRect.Width, catchRect.Height);//新建一个于矩形等大的空白图片
Graphics g = Graphics.FromImage(CatchedBmp);
g.DrawImage(originBitmap, new Rectangle(0, 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.SetImage(CatchedBmp);//将图片保存到剪贴板
g.Dispose();
catchFinished = false;
CatchedBmp.Dispose();
this.DialogResult = DialogResult.OK;
this.Close();
}
}
}
}