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

namespace NetLibrary
{
    public class HtmlCapture
    {
        #region html转图片
        public static void ConverUrl(string url, string imgSavePath, int Width, int Height)
        {
            string ImagePath = string.Empty;
            WebBrowser web = new WebBrowser();
            web.Navigate(url);
            while (web.ReadyState != WebBrowserReadyState.Complete)
            {
                System.Windows.Forms.Application.DoEvents();
            }
            Rectangle screen = Screen.PrimaryScreen.Bounds;
            Size? imgsize = null;
            //set the webbrowser width and hight
            if (Width == 0)
            {
                web.Width = screen.Width;
                web.Height = screen.Height;
            }
            else
            {
                web.Width = Width;
                web.Height = 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 > web.Width ? body.Width : web.Width,
                 body.Height > web.Height ? body.Height : web.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);
            }
            bitmap.Save(imgSavePath, System.Drawing.Imaging.ImageFormat.Jpeg);
            bitmap.Dispose();
            web.Dispose();
        }
        #endregion
        #region html文档转图片
        public static void ConverHTML(string html, string imgSavePath, int Width, int Height)
        {
            string dir = AppDomain.CurrentDomain.BaseDirectory + "ServerCookies";
            if (Directory.Exists(dir) == false) Directory.CreateDirectory(dir);
            string tempPath = dir + "/" + Guid.NewGuid().ToString() + ".html";
            if (File.Exists(tempPath) == false) File.Create(tempPath).Close();
            File.AppendAllText(tempPath, html);
            ConverUrl(tempPath, imgSavePath, Width, Height);
            File.Delete(tempPath);
        }
        #endregion

    }

    #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
}