C# 实现HTML转换成图片的方法

//调用委托来实现。返回值在定时器完成后才有用，比较难接收。


using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Runtime.InteropServices;
using System.Windows.Forms;
using System.Drawing;
using System.Runtime.InteropServices.ComTypes;

namespace FormatApplication.CommonClass
{
/// <summary>
/// 对HTML进行图片转换。
/// </summary>
public class ConvertHTML
{
private ConvertHTML() { }
/// <summary>
/// 图片保存路径。
/// </summary>
private static string SAVEHTMLIMAGE = string.Empty;

/// <summary>
/// 把网页转换成图片形式。
/// </summary>
/// <param name="htmlPath"></param>
/// <returns></returns>
public static void HTMLConvertImage(string htmlPath)
{
SAVEHTMLIMAGE = string.Empty;
HtmlCapture hcap = new HtmlCapture();
hcap.HtmlImageCapture += new HtmlCapture.HtmlCaptureEvent(hcap_HtmlImageCapture);
hcap.Create(htmlPath);
}

static void hcap_HtmlImageCapture(object sender, Uri url, Bitmap image)
{
SAVEHTMLIMAGE = @"E:\cheng_Text\FormatApplication\测试文件\ConvertHTML.jpg";
image.Save(SAVEHTMLIMAGE);
image.Dispose();
}

/// <summary>
///
/// </summary>
/// <returns></returns>
public static string ProduceImagePath()
{

return SAVEHTMLIMAGE;
}
}

#region==========IViewObje【实现接口类】================
[ComVisible(true), ComImport()]
[GuidAttribute("0000010d-0000-0000-C000-000000000046")]
[InterfaceTypeAttribute(ComInterfaceType.InterfaceIsIUnknown)]
public interface IViewObject
{
[return: MarshalAs(UnmanagedType.I4)]
[PreserveSig]
int Draw(
[MarshalAs(UnmanagedType.U4)] UInt32 dwDrawAspect,
int lindex,
IntPtr pvAspect,
[In] IntPtr ptd,
IntPtr hdcTargetDev,
IntPtr hdcDraw,
[MarshalAs(UnmanagedType.Struct)] ref Rectangle lprcBounds,
[MarshalAs(UnmanagedType.Struct)] ref Rectangle lprcWBounds,
IntPtr pfnContinue,
[MarshalAs(UnmanagedType.U4)] UInt32 dwContinue);
[PreserveSig]
int GetColorSet([In, MarshalAs(UnmanagedType.U4)] int dwDrawAspect,
int lindex, IntPtr pvAspect, [In] IntPtr ptd,
IntPtr hicTargetDev, [Out] IntPtr 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)] IAdviseSink pAdvSink);
void GetAdvise([In, Out, MarshalAs(UnmanagedType.LPArray)] int[] paspects,
[In, Out, MarshalAs(UnmanagedType.LPArray)] int[] advf,
[In, Out, MarshalAs(UnmanagedType.LPArray)] IAdviseSink[] pAdvSink);
}
#endregion

#region=============HtmlCapture【HTML抓图片方法实现】===============
public class HtmlCapture
{
private WebBrowser web;
private Timer tready;
private Rectangle screen;
private Size? imgsize = null;

//an event that triggers when the html document is captured
public delegate void HtmlCaptureEvent(object sender,
Uri url, Bitmap image);
public event HtmlCaptureEvent HtmlImageCapture;

//class constructor
public HtmlCapture()
{
//initialise the webbrowser and the timer
web = new WebBrowser();
tready = new Timer();
tready.Interval = 2000;
screen = Screen.PrimaryScreen.Bounds;
//set the webbrowser width and hight
web.Width = screen.Width;
web.Height = screen.Height;
//suppress script errors and hide scroll bars
web.ScriptErrorsSuppressed = true;
web.ScrollBarsEnabled = false;
//attached events
web.Navigating +=
new WebBrowserNavigatingEventHandler(web_Navigating);
web.DocumentCompleted += new
WebBrowserDocumentCompletedEventHandler(web_DocumentCompleted);
tready.Tick += new EventHandler(tready_Tick);
}

#region Public methods
public void Create(string url)
{
imgsize = null;
web.Navigate(url);
}

public void Create(string url, Size imgsz)
{
this.imgsize = imgsz;
web.Navigate(url);
}
#endregion

#region Events
void web_DocumentCompleted(object sender,
WebBrowserDocumentCompletedEventArgs e)
{
//start the timer
tready.Start();
}

void web_Navigating(object sender, WebBrowserNavigatingEventArgs e)
{
//stop the timer
tready.Stop();
}

void tready_Tick(object sender, EventArgs e)
{
//stop the timer
tready.Stop();
//get the size of the document's body
Rectangle body = web.Document.Body.ScrollRectangle;

//check if the document width/height is greater than screen width/height
Rectangle docRectangle = new Rectangle()
{
Location = new Point(0, 0),
Size = new Size(body.Width > screen.Width ? body.Width : screen.Width,
body.Height > screen.Height ? body.Height : screen.Height)
};
//set the width and height of the WebBrowser object
web.Width = docRectangle.Width;
web.Height = docRectangle.Height;

//if the imgsize is null, the size of the image will
//be the same as the size of webbrowser object
//otherwise set the image size to imgsize
Rectangle imgRectangle;
if (imgsize == null)
imgRectangle = docRectangle;
else
imgRectangle = new Rectangle()
{
Location = new Point(0, 0),
Size = imgsize.Value
};
//create a bitmap object
Bitmap bitmap = new Bitmap(imgRectangle.Width, imgRectangle.Height);
//get the viewobject of the WebBrowser
IViewObject ivo = web.Document.DomDocument as IViewObject;

using (Graphics g = Graphics.FromImage(bitmap))
{
//get the handle to the device context and draw
IntPtr hdc = g.GetHdc();
ivo.Draw(1, -1, IntPtr.Zero, IntPtr.Zero,
IntPtr.Zero, hdc, ref imgRectangle,
ref docRectangle, IntPtr.Zero, 0);
g.ReleaseHdc(hdc);
}
//invoke the HtmlImageCapture event
HtmlImageCapture(this, web.Url, bitmap);

}
#endregion
}
#endregion
}
----------------------------------------------------------------------------------------------

//另一种用同步上，在上一个方法上修改。






/// <summary>
/// 通过WebBrowser控件来实现从HTML到Bmp图片的生成。
/// </summary>
/// <param name="htmPath">HTML路径</param>
/// <returns>Bmp图片路径</returns>
private static string ConverHTML(string htmPath)
{
string ImagePath = string.Empty;
WebBrowser web = new WebBrowser();
web.Navigate(htmPath);
while (web.ReadyState != WebBrowserReadyState.Complete)
{
System.Windows.Forms.Application.DoEvents();
}
Rectangle screen = Screen.PrimaryScreen.Bounds;
Size? imgsize = null;
//set the webbrowser width and hight
web.Width = screen.Width;
web.Height = screen.Height;
//suppress script errors and hide scroll bars
web.ScriptErrorsSuppressed = true;
web.ScrollBarsEnabled = false;
Rectangle body = web.Document.Body.ScrollRectangle;

//check if the document width/height is greater than screen width/height
Rectangle docRectangle = new Rectangle()
{
Location = new Point(0, 0),
Size = new Size(body.Width > screen.Width ? body.Width : screen.Width,
body.Height > screen.Height ? body.Height : screen.Height)
};
//set the width and height of the WebBrowser object
web.Width = docRectangle.Width;
web.Height = docRectangle.Height;

//if the imgsize is null, the size of the image will
//be the same as the size of webbrowser object
//otherwise set the image size to imgsize
Rectangle imgRectangle;
if (imgsize == null)
imgRectangle = docRectangle;
else
imgRectangle = new Rectangle()
{
Location = new Point(0, 0),
Size = imgsize.Value
};
//create a bitmap object
Bitmap bitmap = new Bitmap(imgRectangle.Width - 24, imgRectangle.Height);
//get the viewobject of the WebBrowser
IViewObject ivo = web.Document.DomDocument as IViewObject;

using (Graphics g = Graphics.FromImage(bitmap))
{
//get the handle to the device context and draw
IntPtr hdc = g.GetHdc();
ivo.Draw(1, -1, IntPtr.Zero, IntPtr.Zero,
IntPtr.Zero, hdc, ref imgRectangle,
ref docRectangle, IntPtr.Zero, 0);
g.ReleaseHdc(hdc);
}
SAVEWORDJPG = string.Format(@"E:\cheng_Text\FormatApplication\测试文件\{0}.bmp", Guid.NewGuid().ToString());
bitmap.Save(SAVEWORDJPG, System.Drawing.Imaging.ImageFormat.Bmp);
bitmap.Dispose();
web.Dispose();
DeleteTempFile(TEMPHTMLPATH);
return SAVEWORDJPG;
}

/// <summary>
/// 删除指定的临时文件。
/// </summary>
/// <param name="filePath"></param>
private static void DeleteTempFile(string filePath)
{
//删除临时HTML文件 。
File.Delete(filePath);
//删除目录文件内容。
string[] files = filePath.Split('.');
if (files[1].ToLower().Equals("htm"))
{
string dirPath = files[0] + ".files";
foreach (string f in Directory.GetFileSystemEntries(dirPath))
{
// 如果是文件存在
if (File.Exists(f))
{
FileInfo fi = new FileInfo(f);
if (fi.Attributes.ToString().IndexOf("Readonly") != 1)
{
fi.Attributes = FileAttributes.Normal;
}
// 直接删除其中的文件
File.Delete(f);
}
}
Directory.Delete(dirPath);
}
}

#region==========IViewObje【实现接口类】================
[ComVisible(true), ComImport()]
[GuidAttribute("0000010d-0000-0000-C000-000000000046")]
[InterfaceTypeAttribute(ComInterfaceType.InterfaceIsIUnknown)]
public interface IViewObject
{
[return: MarshalAs(UnmanagedType.I4)]
[PreserveSig]
int Draw(
[MarshalAs(UnmanagedType.U4)] UInt32 dwDrawAspect,
int lindex,
IntPtr pvAspect,
[In] IntPtr ptd,
IntPtr hdcTargetDev,
IntPtr hdcDraw,
[MarshalAs(UnmanagedType.Struct)] ref Rectangle lprcBounds,
[MarshalAs(UnmanagedType.Struct)] ref Rectangle lprcWBounds,
IntPtr pfnContinue,
[MarshalAs(UnmanagedType.U4)] UInt32 dwContinue);
[PreserveSig]
int GetColorSet([In, MarshalAs(UnmanagedType.U4)] int dwDrawAspect,
int lindex, IntPtr pvAspect, [In] IntPtr ptd,
IntPtr hicTargetDev, [Out] IntPtr 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)] IAdviseSink pAdvSink);
void GetAdvise([In, Out, MarshalAs(UnmanagedType.LPArray)] int[] paspects,
[In, Out, MarshalAs(UnmanagedType.LPArray)] int[] advf,
[In, Out, MarshalAs(UnmanagedType.LPArray)] IAdviseSink[] pAdvSink);
}
#endregion