winform简单截图
//该代码实现简单截图，鼠标左键按下开始截图，移动过程中红线方框确定截图范围，左键放开时弹出保存对话框，选好路径保存就OK。
using System;
using System.Collections.Generic;using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Drawing.Imaging;
using System.Linq;
using System.Text;
using System.Windows.Forms;
namespace chartdemo
{
public partial class Form4 : Form
{
public Form4()
{
InitializeComponent();
}
Point startPoint = new Point();
Point endPoint = new Point();
int width;
int height;
private void Form4_MouseDown(object sender, MouseEventArgs e)
{
if (e.Button == System.Windows.Forms.MouseButtons.Left)
{
startPoint = PointToScreen(e.Location);
}
}
private void Form4_MouseMove(object sender, MouseEventArgs e)
{
if (e.Button == System.Windows.Forms.MouseButtons.Left)
{
Graphics g = this.CreateGraphics();
Pen p = new Pen(Color.Red, 1);
this.Refresh();
Point tP = new Point();
tP = proccessPoint(startPoint,PointToScreen(e.Location));
g.DrawRectangle(p, tP.X-this.Location.X-4, tP.Y-this.Location.Y-30, width, height);
}
}
bool flag = false;
private void Form4_MouseUp(object sender, MouseEventArgs e)
{
endPoint = PointToScreen(e.Location);
startPoint = proccessPoint(startPoint, endPoint);
if (flag)
{
IntPtr dc1 = CreateDC("DISPLAY", null, null, (IntPtr)null);//创建显示器的DC
Graphics g1 = Graphics.FromHdc(dc1);//由句柄创建Graphics
Bitmap MyImage = new Bitmap(width, height, g1);//创建与屏幕同大小的Bitmap
Graphics g2 = Graphics.FromImage(MyImage);//获得屏幕的句柄
IntPtr dc3 = g1.GetHdc();//获得位图的句柄
IntPtr dc2 = g2.GetHdc();//把当前屏幕捕获到位图中
BitBlt(dc2, 0, 0, width, height, dc3, startPoint.X, startPoint.Y, 13369376);//把当前屏幕拷贝到位图中
g1.ReleaseHdc(dc3);//释放屏幕句柄
g2.ReleaseHdc(dc2);
string filePath = null;
SaveFileDialog saveFileDialog1 = new SaveFileDialog();
saveFileDialog1.RestoreDirectory = true;//打开上一次所打开的目录
if (saveFileDialog1.ShowDialog() == DialogResult.OK)
{
filePath = saveFileDialog1.FileName.ToString()+".jpeg";
}
MyImage.Save(filePath, ImageFormat.Jpeg);
}
else
{
MessageBox.Show("错误");
}
}
public Point proccessPoint(Point sP,Point eP)
{
width = eP.X - sP.X;
height = eP.Y - sP.Y;
if (width == 0 || height == 0)
{
flag = false;
}
else if (width > 0 && height > 0)
{
flag = true;
}
else if (width > 0 && height < 0)
{
sP.Y += height;
height = Math.Abs(height);
flag = true;
}
else if (width < 0 && height > 0)
{
sP.X += width;
width = Math.Abs(width);
flag = true;
}
else
{
sP.X += width;
sP.Y += height;
height = Math.Abs(height);
width = Math.Abs(width);
flag = true;
}
return sP;
}
private void Form4_Load(object sender, EventArgs e)
{
width = 0;
height = 0;
}
[System.Runtime.InteropServices.DllImportAttribute("gdi32.dll")]
private static extern bool BitBlt(
IntPtr hdcDest, // 目标设备的句柄
int nXDest, // 目标对象的左上角的X坐标
int nYDest, // 目标对象的左上角的X坐标
int nWidth, // 目标对象的矩形的宽度
int nHeight, // 目标对象的矩形的长度
IntPtr hdcSrc, // 源设备的句柄
int nXSrc, // 源对象的左上角的X坐标
int nYSrc, // 源对象的左上角的X坐标
System.Int32 dwRop // 光栅的操作值
);
[System.Runtime.InteropServices.DllImportAttribute("gdi32.dll")]
private static extern IntPtr CreateDC(
string lpszDriver, // 驱动名称
string lpszDevice, // 设备名称
string lpszOutput, // 无用，可以设定位"NULL"
IntPtr lpInitData // 任意的打印机数据
);
}
}