本文实例主要实现了网页照相机程序的功能。C#实现将网页保存成图片格式，简单实现网页拍照，主要是基于ActiveX 组件的网页快照类，AcitveX 必须实现 IViewObject 接口。因此读者完全可扩展此类将其用于你的C#软件项目中。在此特别感谢作者：随飞提供的代码。
主要功能代码如下：
using System;
using System.Collections.Generic;
using System.Text;
using System.Runtime.InteropServices;
using System.Runtime.InteropServices.ComTypes;
using System.Drawing;
using System.Windows.Forms;
namespace SnapLibrary
{
/// <summary>
/// ActiveX 组件快照类，用于网页拍照，将网页保存成图片
/// AcitveX 必须实现 IViewObject 接口
/// 作者:随飞
/// </summary>
public class Snapshot
{
/// <summary>
/// 取快照
/// </summary>
/// <param name="pUnknown">Com 对象</param>
/// <param name="bmpRect">图象大小</param>
/// <returns></returns>
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
SnapLibrary.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(SnapLibrary.UnsafeNativeMethods.IViewObject)) as SnapLibrary.UnsafeNativeMethods.IViewObject;
//调用Draw方法
ViewObject.Draw((int)DVASPECT.DVASPECT_CONTENT,
-1,
IntPtr.Zero,
null,
IntPtr.Zero,
hDrawDC.GetHdc(),
new NativeMethods.COMRECT(bmpRect),
null,
IntPtr.Zero,
0);
Marshal.Release(pViewObject);
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
throw ex;
}
//释放
hDrawDC.Dispose();
return pPicture;
}
}
}