网页快照 - C#实现

 /// <summary>
 /// 图片类型枚举
 /// </summary>
 public enum ImageType
 {
     GIF = ,
     JPG = ,
     PNG =
 }

 /// <summary>
 ///     图片辅助类
 /// </summary>
 public class ImageHelper
 {
     /// <summary>
     /// 将Url地址保存为图片
     /// </summary>
     /// <param name="url">网页路径</param>
     /// <param name="savePath">图片存放路径</param>
     /// <param name="imageType">图片类型</param>
     /// <returns></returns>
     public static string SaveUrlToImage(string url, string savePath, ImageType imageType)
     {
         var uri = new Uri(url);
         using (var bit = GetHtmlImage(uri, Screen.PrimaryScreen.Bounds.Width))
         {
             switch (imageType)
             {
                 case ImageType.GIF:
                     bit.Save(savePath, ImageFormat.Gif);
                     break;
                 case ImageType.JPG:
                     bit.Save(savePath, ImageFormat.Jpeg);
                     break;
                 case ImageType.PNG:
                     bit.Save(savePath, ImageFormat.Png);
                     break;
                 default:
                     bit.Save(savePath, ImageFormat.Jpeg);
                     break;
             }
             return savePath;
         }
     }

     protected static Bitmap GetHtmlImage(Uri urlString, int width)
     {
         using (var control = new WebBrowser { Size = new Size(width, ), Url = urlString, ScriptErrorsSuppressed = true })
         {
             while (control.ReadyState != WebBrowserReadyState.Complete)
             {
                 Application.DoEvents();
             }
             if (control.Document != null)
             {
                 if (control.Document.Body != null)
                 {
                     control.Height = control.Document.Body.ScrollRectangle.Height + ;
                 }
             }
             control.Url = urlString;
             var snap = new WebControlImage.Snapshot();
             var bitmap = snap.TakeSnapshot(control.ActiveXInstance, new Rectangle(, , control.Width, control.Height));
             control.Dispose();
             return bitmap;
         }
     }

     /// WebBrowser获取图形
     protected class WebControlImage
     {
         internal static class NativeMethods
         {
             [StructLayout(LayoutKind.Sequential)]
             public sealed class TagDvtargetdevice
             {
                 [MarshalAs(UnmanagedType.U4)]
                 public int tdSize;
                 [MarshalAs(UnmanagedType.U2)]
                 public short tdDriverNameOffset;
                 [MarshalAs(UnmanagedType.U2)]
                 public short tdDeviceNameOffset;
                 [MarshalAs(UnmanagedType.U2)]
                 public short tdPortNameOffset;
                 [MarshalAs(UnmanagedType.U2)]
                 public short tdExtDevmodeOffset;
             }

             [StructLayout(LayoutKind.Sequential)]
             public class Comrect
             {
                 public int left;
                 public int top;
                 public int right;
                 public int bottom;

                 public Comrect()
                 {
                 }

                 public Comrect(Rectangle r)
                 {
                     left = r.X;
                     top = r.Y;
                     right = r.Right;
                     bottom = r.Bottom;
                 }

                 public Comrect(int left, int top, int right, int bottom)
                 {
                     this.left = left;
                     this.top = top;
                     this.right = right;
                     this.bottom = bottom;
                 }

                 public static Comrect FromXywh(int x, int y, int width, int height)
                 {
                     return new Comrect(x, y, x + width, y + height);
                 }

                 public override string ToString()
                 {
                     return string.Concat("Left = ", left, " Top ", top, " Right = ", right, " Bottom = ", bottom);
                 }
             }

             [StructLayout(LayoutKind.Sequential)]
             public sealed class TagLogpalette
             {
                 [MarshalAs(UnmanagedType.U2)]
                 public short palVersion;
                 [MarshalAs(UnmanagedType.U2)]
                 public short palNumEntries;
             }
         }

         public class Snapshot
         {
             /// 图象大小
             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
                 IntPtr viewObject;
                 //内存图
                 var bitmap = new Bitmap(bmpRect.Width, bmpRect.Height);
                 var image = Graphics.FromImage(bitmap);
                 //获取接口
                 object hret = Marshal.QueryInterface(Marshal.GetIUnknownForObject(pUnknown), ref UnsafeNativeMethods.IidIViewObject, out viewObject);
                 try
                 {
                     var o = (UnsafeNativeMethods.IViewObject)Marshal.GetTypedObjectForIUnknown(viewObject, typeof(UnsafeNativeMethods.IViewObject));
                     //调用Draw方法
                     if (o != null)
                     {
                         o.Draw((int)DVASPECT.DVASPECT_CONTENT, -, IntPtr.Zero, null, IntPtr.Zero, image.GetHdc(), new NativeMethods.Comrect(bmpRect), null, IntPtr.Zero, );
                     }
                 }
                 catch (Exception ex)
                 {
                     Console.WriteLine(ex.Message);
                     throw;
                 }
                 //释放
                 image.Dispose();
                 return bitmap;
             }
         }

         [SuppressUnmanagedCodeSecurity]
         internal static class UnsafeNativeMethods
         {
             public static Guid IidIViewObject = new Guid("{0000010d-0000-0000-C000-000000000046}");

             [ComImport, Guid("0000010d-0000-0000-C000-000000000046"),
                 InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
             public interface IViewObject
             {
                 [PreserveSig]
                 int Draw([In, MarshalAs(UnmanagedType.U4)] int dwDrawAspect, int lindex, IntPtr pvAspect,
                     [In] NativeMethods.TagDvtargetdevice ptd, IntPtr hdcTargetDev, IntPtr hdcDraw,
                     [In] NativeMethods.Comrect lprcBounds, [In] NativeMethods.Comrect lprcWBounds,
                     IntPtr pfnContinue,
                     [In] int dwContinue);

                 [PreserveSig]
                 int GetColorSet([In, MarshalAs(UnmanagedType.U4)] int dwDrawAspect, int lindex, IntPtr pvAspect,
                     [In] NativeMethods.TagDvtargetdevice ptd, IntPtr hicTargetDev,
                     [Out] NativeMethods.TagLogpalette 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);
             }
         }
     }
 }