C#实现鼠标裁剪图像功能

本文实例为大家分享了c#实现鼠标裁剪图像的具体代码，供大家参考，具体内容如下

c#的图像裁剪很容易操作，这里给个实现的例子。

关键是需要处理鼠标的事件和一些更新

实现鼠标移动的代码.注意更新不要全部重画,只有选择矩形部分重画

private void form1_mousemove(object sender, mouseeventargs e)
 {

  if (track_move)
  endpoint = new point(e.x, e.y);
  else
  {
  return;
  }
  rect1 = new rectangle(stpoint.x, stpoint.y, endpoint.x - stpoint.x, endpoint.y - stpoint.y);

  rectangle tempr = new rectangle(rect1.x, rect1.y, rect1.width + 2, rect1.height + 2);
  this.invalidate(tempr);
 }

选择结束的处理代码.

private void form1_mouseup(object sender, mouseeventargs e)
 {
  if (e.button == mousebuttons.left && track_move==true )
  {
  track_move = false;
  endpoint = new point(e.x, e.y);
  rect1 = new rectangle(stpoint.x, stpoint.y, endpoint.x - stpoint.x, endpoint.y - stpoint.y);
  rectangle rectorg = new rectangle(borg.x, borg.y, image1.width, image1.height);
  if (rect1.width <= 0)
   return;
  if (rect1.height <= 0)
   return;
  if (rectorg.contains(rect1))
  {
   rectangle rectadj = new rectangle(rect1.x - borg.x, rect1.y - borg.y, rect1.width, rect1.height);
   bitmap cropimge = image1.clone(rectadj, system.drawing.imaging.pixelformat.format24bpprgb);
   picturebox2.image = cropimge;
  }
  else
  {
   picturebox2.image = null;
  }
  this.invalidate();
 }
}

程序的整个代码

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.runtime.interopservices;

namespace imageforms
{
 static class program
 {
 /// <summary>
 /// 应用程序的主入口点。
 /// </summary>
 [stathread]
 static void main()
 {
  application.enablevisualstyles();
  application.setcompatibletextrenderingdefault(false);
  application.run(new form1());
 }
 }
 public partial class form1 : form
 {
 private system.windows.forms.picturebox picturebox2;
 private system.windows.forms.label label1;
 public form1()
 {
  initializecomponent();
 }

 private void picturebox1_click(object sender, eventargs e)
 {

 }

 private void form1_load(object sender, eventargs e)
 {
  showimg();

 }
 bitmap image1;
 private void showimg()
 {
  int wd = 400;
  int hg = 200;
  int len = wd * hg * 3;
  byte[] pdata = new byte[len];
  for (int i = 0; i < len; i++)
  {
  if (i > 3 * wd * (hg / 2))
  {
   pdata[i] = 255;
  }
  else
  {
   pdata[i] = 0;
  }
  }

  try
  {
  image1 = new bitmap(wd, hg, system.drawing.imaging.pixelformat.format24bpprgb);
  for (int y = 0; y < hg; y++)
  {
   for (int x = 0; x < wd; x++)
   {
   color crr = color.fromargb(pdata[3 * wd * y + x], pdata[3 * wd * y + x], pdata[3 * wd * y + x]);
   image1.setpixel(x, y, crr);
   }
  }
  // set the picturebox to display the image.
  // picturebox1.image = image1;

  }
  catch (argumentexception)
  {
  messagebox.show("there was an error check data.");
  }
 }
 point stpoint,endpoint; 
 rectangle rect1; 
 point borg = new point(20, 20);
 protected override void onpaint(painteventargs e)
 {
  
  base.onpaint(e);
  e.graphics.drawimage(image1, borg);
  if (rect1 != null )
  {
   e.graphics.drawrectangle(new pen(color.red, 1), rect1);
  }
  
 }

 private void form1_mousedown(object sender, mouseeventargs e)
 {
  if (e.button == mousebuttons.left)
  {
  stpoint = new point(e.x, e.y);
  track_move = true;
  return;
  }
  track_move = false;
 }

 private void form1_mouseup(object sender, mouseeventargs e)
 {
  if (e.button == mousebuttons.left && track_move==true )
  {
  track_move = false;
  endpoint = new point(e.x, e.y);
  rect1 = new rectangle(stpoint.x, stpoint.y, endpoint.x - stpoint.x, endpoint.y - stpoint.y);
  rectangle rectorg = new rectangle(borg.x, borg.y, image1.width, image1.height);
  if (rect1.width <= 0)
   return;
  if (rect1.height <= 0)
   return;
  if (rectorg.contains(rect1))
  {
   rectangle rectadj = new rectangle(rect1.x - borg.x, rect1.y - borg.y, rect1.width, rect1.height);
   bitmap cropimge = image1.clone(rectadj, system.drawing.imaging.pixelformat.format24bpprgb);
   picturebox2.image = cropimge;
  }
  else
  {
   picturebox2.image = null;
  }
  this.invalidate();
  }
 }
 bool track_move=false ;
 private void form1_mousemove(object sender, mouseeventargs e)
 {

  if (track_move)
  endpoint = new point(e.x, e.y);
  else
  {
  return;
  }
  rect1 = new rectangle(stpoint.x, stpoint.y, endpoint.x - stpoint.x, endpoint.y - stpoint.y);

  rectangle tempr = new rectangle(rect1.x, rect1.y, rect1.width + 2, rect1.height + 2);
  this.invalidate(tempr);
 }
 private system.componentmodel.icontainer components = null;

 private void initializecomponent()
 {
  this.picturebox2 = new system.windows.forms.picturebox();
  this.label1 = new system.windows.forms.label();
  ((system.componentmodel.isupportinitialize)(this.picturebox2)).begininit();
  this.suspendlayout();
  // 
  // picturebox2
  // 
  this.picturebox2.location = new system.drawing.point(605, 103);
  this.picturebox2.name = "picturebox2";
  this.picturebox2.size = new system.drawing.size(227, 173);
  this.picturebox2.tabindex = 1;
  this.picturebox2.tabstop = false;
  // 
  // label1
  // 
  this.label1.autosize = true;
  this.label1.location = new system.drawing.point(602, 58);
  this.label1.name = "label1";
  this.label1.size = new system.drawing.size(127, 15);
  this.label1.tabindex = 2;
  this.label1.text = "鼠标左键选择裁剪";
  // 
  // form1
  // 
  this.autoscaledimensions = new system.drawing.sizef(8f, 15f);
  this.autoscalemode = system.windows.forms.autoscalemode.font;
  this.clientsize = new system.drawing.size(844, 558);
  this.controls.add(this.label1);
  this.controls.add(this.picturebox2);
  this.name = "form1";
  this.text = "form1";
  this.load += new system.eventhandler(this.form1_load);
  this.mouseup += new system.windows.forms.mouseeventhandler(this.form1_mouseup);
  this.mousedown += new system.windows.forms.mouseeventhandler(this.form1_mousedown);
  this.mousemove += new system.windows.forms.mouseeventhandler(this.form1_mousemove);
  ((system.componentmodel.isupportinitialize)(this.picturebox2)).endinit();
  this.resumelayout(false);
  this.performlayout();

 }
 protected override void dispose(bool disposing)
 {
  if (disposing && (components != null))
  {
  components.dispose();
  }
  base.dispose(disposing);
 }

 }
}

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。