writehtml方法中使用到的一个类

/******************************** * 微软自身的接口声明 * 由于找不到可用的Interface声明 * 只好祭出Reflector，反编译Windows.Forms * 需要的朋友可以不用辛苦的自己搞了  * ******************************/using System;using System.IO;using System.Runtime.CompilerServices;using System.Runtime.InteropServices;using System.Security;using System.Security.Permissions;using System.Text;

namespace HtmlEditor {

  [StructLayout(LayoutKind.Sequential)]  public class STATSTG {    [MarshalAs(UnmanagedType.LPWStr)]    public string pwcsName;    public int type;    [MarshalAs(UnmanagedType.I8)]    public long cbSize;    [MarshalAs(UnmanagedType.I8)]    public long mtime;    [MarshalAs(UnmanagedType.I8)]    public long ctime;    [MarshalAs(UnmanagedType.I8)]    public long atime;    [MarshalAs(UnmanagedType.I4)]    public int grfMode;    [MarshalAs(UnmanagedType.I4)]    public int grfLocksSupported;    public int clsid_data1;    [MarshalAs(UnmanagedType.I2)]    public short clsid_data2;    [MarshalAs(UnmanagedType.I2)]    public short clsid_data3;    [MarshalAs(UnmanagedType.U1)]    public byte clsid_b0;    [MarshalAs(UnmanagedType.U1)]    public byte clsid_b1;    [MarshalAs(UnmanagedType.U1)]    public byte clsid_b2;    [MarshalAs(UnmanagedType.U1)]    public byte clsid_b3;    [MarshalAs(UnmanagedType.U1)]    public byte clsid_b4;    [MarshalAs(UnmanagedType.U1)]    public byte clsid_b5;    [MarshalAs(UnmanagedType.U1)]    public byte clsid_b6;    [MarshalAs(UnmanagedType.U1)]    public byte clsid_b7;    [MarshalAs(UnmanagedType.I4)]    public int grfStateBits;    [MarshalAs(UnmanagedType.I4)]    public int reserved;    public STATSTG() {    }  }  [SuppressUnmanagedCodeSecurity]  internal class UnsafeNativeMethods {    [ComImport, InterfaceType(ComInterfaceType.InterfaceIsIUnknown), Guid("7FD52380-4E07-101B-AE2D-08002B2EC713")]      public interface IPersistStreamInit {      void GetClassID(out Guid pClassID);      [PreserveSig]      int IsDirty();      void Load([In, MarshalAs(UnmanagedType.Interface)] IStream pstm);      void Save([In, MarshalAs(UnmanagedType.Interface)] IStream pstm, [In, MarshalAs(UnmanagedType.Bool)] bool fClearDirty);      void GetSizeMax([Out, MarshalAs(UnmanagedType.LPArray)] long pcbSize);      void InitNew();    }    [ComImport, InterfaceType(ComInterfaceType.InterfaceIsIUnknown), Guid("0000000C-0000-0000-C000-000000000046")]      public interface IStream {      int Read(IntPtr buf, int len);      int Write(IntPtr buf, int len);      [return: MarshalAs(UnmanagedType.I8)]      long Seek([In, MarshalAs(UnmanagedType.I8)] long dlibMove, int dwOrigin);      void SetSize([In, MarshalAs(UnmanagedType.I8)] long libNewSize);      [return: MarshalAs(UnmanagedType.I8)]      long CopyTo([In, MarshalAs(UnmanagedType.Interface)] IStream pstm, [In, MarshalAs(UnmanagedType.I8)] long cb, [Out, MarshalAs(UnmanagedType.LPArray)] long[] pcbRead);      void Commit(int grfCommitFlags);      void Revert();      void LockRegion([In, MarshalAs(UnmanagedType.I8)] long libOffset, [In, MarshalAs(UnmanagedType.I8)] long cb, int dwLockType);      void UnlockRegion([In, MarshalAs(UnmanagedType.I8)] long libOffset, [In, MarshalAs(UnmanagedType.I8)] long cb, int dwLockType);      void Stat([Out] STATSTG pStatstg, int grfStatFlag);      [return: MarshalAs(UnmanagedType.Interface)]      IStream Clone();    }

    // Methods    public UnsafeNativeMethods() {    }

    public class ComStreamFromDataStream : IStream {      // Methods      protected ComStreamFromDataStream() {        this.virtualPosition = -1;      }

      public ComStreamFromDataStream(Stream dataStream) {        this.virtualPosition = -1;        if (dataStream == null) {          throw new ArgumentNullException("dataStream");        }        this.dataStream = dataStream;      }

      private void ActualizeVirtualPosition() {        if (this.virtualPosition != -1) {          if (this.virtualPosition > this.dataStream.Length) {            this.dataStream.SetLength(this.virtualPosition);          }          this.dataStream.Position = this.virtualPosition;          this.virtualPosition = -1;        }      }

      public IStream Clone() {        ComStreamFromDataStream.NotImplemented();        return null;      }

      public void Commit(int grfCommitFlags) {        this.dataStream.Flush();        this.ActualizeVirtualPosition();      }

      public long CopyTo(IStream pstm, long cb, long[] pcbRead) {        int num1 = 0x1000;        IntPtr ptr1 = Marshal.AllocHGlobal(num1);        if (ptr1 == IntPtr.Zero) {          throw new OutOfMemoryException();        }        long num2 = 0;        try {          while (num2 < cb) {            int num3 = num1;            if ((num2 + num3) > cb) {              num3 = (int) (cb - num2);            }            int num4 = this.Read(ptr1, num3);            if (num4 == 0) {              goto Label_006C;            }            if (pstm.Write(ptr1, num4) != num4) {              throw ComStreamFromDataStream.EFail("Wrote an incorrect number of bytes");            }            num2 += num4;          }        }        finally {          Marshal.FreeHGlobal(ptr1);        }        Label_006C:          if ((pcbRead != null) && (pcbRead.Length > 0)) {            pcbRead[0] = num2;          }        return num2;      }

      protected static ExternalException EFail(string msg) {        ExternalException exception1 = new ExternalException(msg, -2147467259);        throw exception1;      }

      public Stream GetDataStream() {        return this.dataStream;      }

      public void LockRegion(long libOffset, long cb, int dwLockType) {      }

      protected static void NotImplemented() {        ExternalException exception1 = new ExternalException("Not implemented.", -2147467263);        throw exception1;      }

      public int Read(IntPtr buf, int length) {        byte[] buffer1 = new byte[length];        int num1 = this.Read(buffer1, length);        Marshal.Copy(buffer1, 0, buf, length);        return num1;      }

      public int Read(byte[] buffer, int length) {        this.ActualizeVirtualPosition();        return this.dataStream.Read(buffer, 0, length);      }

      public void Revert() {        ComStreamFromDataStream.NotImplemented();      }

      public long Seek(long offset, int origin) {        long num1 = this.virtualPosition;        if (this.virtualPosition == -1) {          num1 = this.dataStream.Position;        }        long num2 = this.dataStream.Length;        switch (origin) {          case 0: {            if (offset > num2) {              this.virtualPosition = offset;              break;            }            this.dataStream.Position = offset;            this.virtualPosition = -1;            break;          }          case 1: {            if ((offset + num1) > num2) {              this.virtualPosition = offset + num1;              break;            }            this.dataStream.Position = num1 + offset;            this.virtualPosition = -1;            break;          }          case 2: {            if (offset > 0) {              this.virtualPosition = num2 + offset;              break;            }            this.dataStream.Position = num2 + offset;            this.virtualPosition = -1;            break;          }        }        if (this.virtualPosition != -1) {          return this.virtualPosition;        }        return this.dataStream.Position;      }

      public void SetSize(long value) {        this.dataStream.SetLength(value);      }

      public void Stat(STATSTG pstatstg, int grfStatFlag) {        pstatstg.type = 2;        pstatstg.cbSize = this.dataStream.Length;        pstatstg.grfLocksSupported = 2;      }

      public void UnlockRegion(long libOffset, long cb, int dwLockType) {      }

      public int Write(IntPtr buf, int length) {        byte[] buffer1 = new byte[length];        Marshal.Copy(buf, buffer1, 0, length);        return this.Write(buffer1, length);      }

      public int Write(byte[] buffer, int length) {        this.ActualizeVirtualPosition();        this.dataStream.Write(buffer, 0, length);        return length;      }

      // Fields      protected Stream dataStream;      private long virtualPosition;    }  }}