Winform实现将网页生成图片的方法

通常浏览器都有将网页生成图片的功能，本文实例讲述了winform实现将网页生成图片的方法。分享给大家供大家参考。具体方法如下：

工具截图如下：

生成后的图片如下：

手动填写网站地址，可选择图片类型和保持图片地址，来生成页面的图片，当图片路径未选择时则保存桌面；

具体代码如下：

将html生成图片的类

using system; 
using system.collections.generic; 
using system.componentmodel; 
using system.data; 
using system.drawing; 
using system.text; 
using system.windows.forms; 
using system.drawing.imaging; 
using system.runtime.interopservices; 
using system.security;
namespace print
{
  public class test
  {
    public static bitmap gethtmlimage(uri urlstring, int width)
    {
      webbrowser mycontrol = new webbrowser();
      mycontrol.size = new size(width, 10);
      mycontrol.url = urlstring;
      while (mycontrol.readystate != webbrowserreadystate.complete)
      {
        application.doevents();
      }
      mycontrol.height = mycontrol.document.body.scrollrectangle.height + 20;
      mycontrol.url = urlstring;
      webcontrolimage.snapshot snap = new webcontrolimage.snapshot();
      bitmap myimage = snap.takesnapshot(mycontrol.activexinstance, new rectangle(0, 0, mycontrol.width, mycontrol.height));
      mycontrol.dispose();
      return myimage;
    }
    /// 
    /// webbrowser获取图形 
    /// 
    private class webcontrolimage
    {
      internal static class nativemethods
      {
        [structlayout(layoutkind.sequential)]
        public sealed class tagdvtargetdevice
        {
          [marshalas(unmanagedtype.u4)]
          public int tdsize;
          [marshalas(unmanagedtype.u2)]
          public short tddrivernameoffset;
          [marshalas(unmanagedtype.u2)]
          public short tddevicenameoffset;
          [marshalas(unmanagedtype.u2)]
          public short tdportnameoffset;
          [marshalas(unmanagedtype.u2)]
          public short tdextdevmodeoffset;
        }
        [structlayout(layoutkind.sequential)]
        public class comrect
        {
          public int left;
          public int top;
          public int right;
          public int bottom;
          public comrect()
          {
          }
          public comrect(rectangle r)
          {
            this.left = r.x;
            this.top = r.y;
            this.right = r.right;
            this.bottom = r.bottom;
          }
          public comrect(int left, int top, int right, int bottom)
          {
            this.left = left;
            this.top = top;
            this.right = right;
            this.bottom = bottom;
          }
          public static nativemethods.comrect fromxywh(int x, int y, int width, int height)
          {
            return new nativemethods.comrect(x, y, x + width, y + height);
          }
          public override string tostring()
          {
            return string.concat(new object[] { "left = ", this.left, " top ", this.top, " right = ", this.right, " bottom = ", this.bottom });
          }
        }
        [structlayout(layoutkind.sequential)]
        public sealed class taglogpalette
        {
          [marshalas(unmanagedtype.u2)]
          public short palversion;
          [marshalas(unmanagedtype.u2)]
          public short palnumentries;
        }
      }
      public class snapshot
      {
        /// 
        /// ?煺? 
        /// 
        /// com 对象 
        /// 图象大小 
        /// 
        public bitmap takesnapshot(object punknown, rectangle bmprect)
        {
          if (punknown == null)
            return null;
          //必须为com对象 
          if (!marshal.iscomobject(punknown))
            return null;
          //iviewobject 接口 
          unsafenativemethods.iviewobject viewobject = null;
          intptr pviewobject = intptr.zero;
          //内存图 
          bitmap ppicture = new bitmap(bmprect.width, bmprect.height);
          graphics hdrawdc = graphics.fromimage(ppicture);
          //获取接口 
          object hret = marshal.queryinterface(marshal.getiunknownforobject(punknown),
          ref unsafenativemethods.iid_iviewobject, out pviewobject);
          try
          {
            viewobject = marshal.gettypedobjectforiunknown(pviewobject, typeof(unsafenativemethods.iviewobject)) as unsafenativemethods.iviewobject;
            //调用draw方法 
            viewobject.draw((int)system.runtime.interopservices.comtypes.dvaspect.dvaspect_content,
            -1,
            intptr.zero,
            null,
            intptr.zero,
            hdrawdc.gethdc(),
            new nativemethods.comrect(bmprect),
            null,
            intptr.zero,
            0);
          }
          catch (exception ex)
          {
            console.writeline(ex.message);
            throw ex;
          }
          //释放 
          hdrawdc.dispose();
          return ppicture;
        }
      }
      [suppressunmanagedcodesecurity]
      internal static class unsafenativemethods
      {
        public static guid iid_iviewobject = new guid("{0000010d-0000-0000-c000-000000000046}");
        [comimport, guid("0000010d-0000-0000-c000-000000000046"), interfacetype(cominterfacetype.interfaceisiunknown)]
        public interface iviewobject
        {
          [preservesig]
          int draw([in, marshalas(unmanagedtype.u4)] int dwdrawaspect, int lindex, intptr pvaspect, [in] nativemethods.tagdvtargetdevice ptd, intptr hdctargetdev, intptr hdcdraw, [in] nativemethods.comrect lprcbounds, [in] nativemethods.comrect lprcwbounds, intptr pfncontinue, [in] int dwcontinue);
          [preservesig]
          int getcolorset([in, marshalas(unmanagedtype.u4)] int dwdrawaspect, int lindex, intptr pvaspect, [in] nativemethods.tagdvtargetdevice ptd, intptr hictargetdev, [out] nativemethods.taglogpalette ppcolorset);
          [preservesig]
          int freeze([in, marshalas(unmanagedtype.u4)] int dwdrawaspect, int lindex, intptr pvaspect, [out] intptr pdwfreeze);
          [preservesig]
          int unfreeze([in, marshalas(unmanagedtype.u4)] int dwfreeze);
          void setadvise([in, marshalas(unmanagedtype.u4)] int aspects, [in, marshalas(unmanagedtype.u4)] int advf, [in, marshalas(unmanagedtype.interface)] system.runtime.interopservices.comtypes.iadvisesink padvsink);
          void getadvise([in, out, marshalas(unmanagedtype.lparray)] int[] paspects, [in, out, marshalas(unmanagedtype.lparray)] int[] advf, [in, out, marshalas(unmanagedtype.lparray)] system.runtime.interopservices.comtypes.iadvisesink[] padvsink);
        }
      }
    }
  }
}

winfrom后台处理方面代码如下

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.drawing.imaging;

namespace excel文件处理
{
  public partial class html : form
  {
    public html()
    {
      initializecomponent();
    }
    private string imageurl = "";//图片地址
    private string imagename = "";//图片名称
    private void button1_click(object sender, eventargs e)
    {
      string htmlurl = this.txt_url.text.trim(); 
      if (htmlurl=="")
      {
        messagebox.show("请输入网址");
        return;
      } 
      if (imageurl.trim()=="")
      { 
        imageurl = @"c:\users\administrator\desktop";  
      }
      try
      {
        uri ri = new uri(this.txt_url.text);
        bitmap bit = print.test.gethtmlimage(ri, 1200);
        imagename = this.txt_name.text.trim();//图片名称
        if (imagename != "")
        {
          if (imagename.indexof('.') != -1)
          {//当用户输入图片后缀时，将后缀截取
            imagename.substring(0, imagename.lastindexof('.'));
          }
        }
        else
          imagename = datetime.now.ticks.tostring();//时间名称
        switch (this.combobox1.selectedtext)
        {
          case "gif": imageurl += "\\" + imagename + ".gif"; break;
          case "jpg": imageurl += "\\" + imagename + ".jpg"; break;
          case "png": imageurl += "\\" + imagename + ".png"; break;
          default: imageurl += "\\" + imagename + ".png"; break;
        }

        switch (this.combobox1.selectedtext)
        {
          case "gif": bit.save(imageurl, imageformat.gif); break;
          case "jpg": bit.save(imageurl, imageformat.jpeg); break;
          case "png": bit.save(imageurl, imageformat.png); break;
          default: bit.save(imageurl, imageformat.png); break;
        }

        bit = null;
        imageurl = "";//图片地址
        imagename = "";//图片名称
        messagebox.show("生产成功");
      }
      catch
      {
        messagebox.show("网址输入有误！");
        return;
      }
    }

    private void button2_click(object sender, eventargs e)
    { 
      //获取保存路径
      if (this.folderbrowserdialog1.showdialog()==dialogresult.ok)
      {
        if (this.folderbrowserdialog1.selectedpath.trim()!="")
        {
          imageurl = folderbrowserdialog1.selectedpath;
          this.label6.text = imageurl;
        }
      }
    }
  }
}

希望本文所述对大家的c#程序设计有所帮助。