C#html转图片

 

摘抄方法

/// <summary>
/// 类说明:HTML代码转换为图片的公共类
/// 作者：段江涛
/// 时间：2019/10/17 11:16:38
/// </summary>
public class HtmlToPicHelper
{
private static Bitmap ConverHTML(string htmPath)
{
string ImagePath = string.Empty;
WebBrowser web = new WebBrowser();
//web.Navigate(htmPath);
web.DocumentText = 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);
}
return bitmap;
}

public static byte[] ConverPic(string htmlPath)
{
//必须放到独立的线程里面来处理
Bitmap m_Bitmap = null;
Thread m_thread = new Thread(new ThreadStart(() =>
{
m_Bitmap = ConverHTML(htmlPath);
}));
m_thread.SetApartmentState(ApartmentState.STA);
m_thread.Start();
m_thread.Join();

if (m_Bitmap != null)
{
System.IO.MemoryStream ms = new System.IO.MemoryStream();
m_Bitmap.Save(ms, ImageFormat.Jpeg);
byte[] bs = ms.GetBuffer();
ms.Close();
return bs;
}
return new byte[0];
}
}

[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);
}

 

引用：

byte[] bmp = ConsoleApplication1.HtmlToPicHelper.ConverPic(this.TextBox1.Text);
Response.BinaryWrite(bmp);
System.IO.File.WriteAllBytes(@"D:\test.jpg", bmp);