using System;
using System.Drawing;
using System.Drawing.Imaging;
using System.Windows.Forms;
using System.IO;

namespace WindowsFormsApplication1
{
    public class WebCapture
    {
        #region 字段、属性
        private int width;
        private int height;
        private string url;

        /// <summary>
        /// 属性：图片宽
        /// </summary>
        public int Width { get { return width; } }
        /// <summary>
        /// 属性：图片高
        /// </summary>
        public int Height { get { return height; } }
        /// <summary>
        /// 属性：Url
        /// </summary>
        public string Url { get { return url; } }
        #endregion

        #region 构造函数
        /// <summary>
        /// 构造函数
        /// </summary>
        public WebCapture()
        {
            this.width = 0;
            this.height = 0;
            this.url = "http://www.mzwu.com/";
        }

        /// <summary>
        /// 构造函数
        /// </summary>
        /// <param name="url">Url</param>
        public WebCapture(string url)
        {
            this.width = 0;
            this.height = 0;
            this.url = url;
        }

        /// <summary>
        /// 构造函数
        /// </summary>
        /// <param name="width">图片宽</param>
        /// <param name="height">图片高</param>
        /// <param name="url">Url</param>
        public WebCapture(int width,int height,string url)
        {
            this.width = width;
            this.height = height;
            this.url = url;
        }
        #endregion

        /// <summary>
        /// 保存图片
        /// </summary>
        /// <param name="destpath">保存路径</param>
        /// <returns></returns>
        public void Save(string destpath)
        {
            Save(this.url, destpath, this.width, this.height);
        }

        /// <summary>
        /// 保存图片
        /// </summary>
        /// <param name="url">Url</param>
        /// <param name="destpath">保存路径</param>
        /// <returns></returns>
        public void Save(string url, string destpath)
        {
            Save(url, destpath, this.width, this.height);
        }

        /// <summary>
        /// 保存图片
        /// </summary>
        /// <param name="url">Url</param>
        /// <param name="destpath">保存路径</param>
        /// <param name="width">图片宽</param>
        /// <param name="height">图片高</param>
        /// <returns></returns>
        /// <remarks>width,height为0时获取完整大小</remarks>
        public void Save(string url, string destpath, int width, int height)
        {
            //变量
            int scrollWidth, scrollHeight;
            Bitmap bitmap;
            ImageFormat picType;

            //图片格式
            switch (Path.GetExtension(destpath).ToLower())
            {
                case ".gif":
                    picType = System.Drawing.Imaging.ImageFormat.Gif;
                    break;
                case ".jpg":
                case ".jpeg":
                    picType = System.Drawing.Imaging.ImageFormat.Jpeg;
                    break;
                case ".png":
                    picType = System.Drawing.Imaging.ImageFormat.Png;
                    break;
                case ".bmp":
                    picType = System.Drawing.Imaging.ImageFormat.Bmp;
                    break;
                default:
                    picType = System.Drawing.Imaging.ImageFormat.Jpeg;
                    break;
            }

            //抓取图片
            try
            {
                WebBrowser browser = new WebBrowser();
                browser.ScrollBarsEnabled = false;
                browser.DocumentCompleted += delegate(object sender, WebBrowserDocumentCompletedEventArgs e)
                {
                    WebBrowser browser2 = (WebBrowser)sender;
                    if (browser2.ReadyState == WebBrowserReadyState.Interactive)
                    {
                        scrollWidth = browser2.Document.Body.ScrollRectangle.Width;
                        scrollHeight = browser2.Document.Body.ScrollRectangle.Height;
                        if (width == 0) width = scrollWidth;
                        if (height == 0) height = scrollHeight;

                        //核心语句
                        bitmap = new Bitmap(width, height);
                        browser2.Size = new Size(width, height);
                        //部分站点截到的图为空白，MSDN中注明：
                        //此 API 支持 .NET Framework 基础结构，不适合在代码中直接使用。此控件不支持此方法。
                        //http://msdn.microsoft.com/zh-cn/library/system.windows.forms.webbrowserbase.drawtobitmap.aspx
                        browser2.DrawToBitmap(bitmap, new Rectangle(0, 0, width, height));
                        bitmap.Save(destpath, picType);

                        MessageBox.Show(browser2.Document.Body.InnerHtml);
                        bitmap.Dispose();
                        browser2.Dispose();
                    }
                };
                browser.Navigate(url);
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.ToString());
            }
        }
    }
}