/* ====================================================================
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Licensed To the Apache Software Foundation (ASF) under one or more
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contributor license agreements. See the NOTICE file distributed with
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this work for Additional information regarding copyright ownership.
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The ASF licenses this file To You under the Apache License, Version 2.0
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(the "License"); you may not use this file except in compliance with
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the License. You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed To in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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==================================================================== */
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/* ================================================================
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* About NPOI
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* Author: Tony Qu
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* Author's email: tonyqus (at) gmail.com
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* Author's Blog: tonyqus.wordpress.com.cn (wp.tonyqus.cn)
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* HomePage: http://www.codeplex.com/npoi
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* Contributors:
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*
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* ==============================================================*/
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namespace HH.WMS.Utils.NPOI.HPSF
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{
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using System;
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using HH.WMS.Utils.NPOI.Util;
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/// <summary>
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/// Class To manipulate data in the Clipboard Variant (Variant#VT_CF VT_CF) format.
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/// @author Drew Varner (Drew.Varner inOrAround sc.edu)
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/// @since 2002-04-29
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/// </summary>
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public class Thumbnail
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{
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/// <summary>
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/// OffSet in bytes where the Clipboard Format Tag starts in the <c>byte[]</c> returned by SummaryInformation#GetThumbnail()
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/// </summary>
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public const int OFFSet_CFTAG = 4;
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/// <summary>
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/// OffSet in bytes where the Clipboard Format starts in the <c>byte[]</c> returned by SummaryInformation#GetThumbnail()
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/// </summary>
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/// <remarks>This is only valid if the Clipboard Format Tag is CFTAG_WINDOWS</remarks>
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public const int OFFSet_CF = 8;
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/// <summary>
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/// OffSet in bytes where the Windows Metafile (WMF) image data starts in the <c>byte[]</c> returned by SummaryInformation#GetThumbnail()
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/// There is only WMF data at this point in the
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/// <c>byte[]</c> if the Clipboard Format Tag is
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/// CFTAG_WINDOWS and the Clipboard Format is
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/// CF_METAFILEPICT.
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/// </summary>
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/// <remarks>Note: The <c>byte[]</c> that starts at
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/// <c>OFFSet_WMFDATA</c> and ends at
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/// <c>GetThumbnail().Length - 1</c> forms a complete WMF
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/// image. It can be saved To disk with a <c>.wmf</c> file
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/// type and Read using a WMF-capable image viewer.</remarks>
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public const int OFFSet_WMFDATA = 20;
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/// <summary>
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/// Clipboard Format Tag - Windows clipboard format
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/// </summary>
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/// <remarks>A <c>DWORD</c> indicating a built-in Windows clipboard format value</remarks>
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public const int CFTAG_WINDOWS = -1;
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/// <summary>
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/// Clipboard Format Tag - Macintosh clipboard format
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/// </summary>
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/// <remarks>A <c>DWORD</c> indicating a Macintosh clipboard format value</remarks>
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public const int CFTAG_MACINTOSH = -2;
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/// <summary>
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/// Clipboard Format Tag - Format ID
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/// </summary>
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/// <remarks>A GUID containing a format identifier (FMTID). This is rarely used.</remarks>
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public const int CFTAG_FMTID = -3;
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/// <summary>
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/// Clipboard Format Tag - No Data
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/// </summary>
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/// <remarks>A <c>DWORD</c> indicating No data. This is rarely used.</remarks>
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public const int CFTAG_NODATA = 0;
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/// <summary>
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/// Clipboard Format - Windows metafile format. This is the recommended way To store thumbnails in Property Streams.
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/// </summary>
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/// <remarks>Note:This is not the same format used in
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/// regular WMF images. The clipboard version of this format has an
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/// extra clipboard-specific header.</remarks>
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public const int CF_METAFILEPICT = 3;
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/// <summary>
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/// Clipboard Format - Device Independent Bitmap
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/// </summary>
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public const int CF_DIB = 8;
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/// <summary>
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/// Clipboard Format - Enhanced Windows metafile format
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/// </summary>
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public const int CF_ENHMETAFILE = 14;
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/// <summary>
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/// Clipboard Format - Bitmap
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/// </summary>
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/// <remarks>see msdn.microsoft.com/library/en-us/dnw98bk/html/clipboardoperations.asp</remarks>
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[Obsolete]
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public const int CF_BITMAP = 2;
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/**
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* A <c>byte[]</c> To hold a thumbnail image in (
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* Variant#VT_CF VT_CF) format.
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*/
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private byte[] thumbnailData = null;
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/// <summary>
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/// Default Constructor. If you use it then one you'll have To Add
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/// the thumbnail <c>byte[]</c> from {@link
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/// SummaryInformation#GetThumbnail()} To do any useful
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/// manipulations, otherwise you'll Get a
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/// <c>NullPointerException</c>.
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/// </summary>
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public Thumbnail()
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{
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}
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/// <summary>
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/// Initializes a new instance of the <see cref="Thumbnail"/> class.
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/// </summary>
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/// <param name="thumbnailData">The thumbnail data.</param>
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public Thumbnail(byte[] thumbnailData)
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{
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this.thumbnailData = thumbnailData;
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}
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/// <summary>
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/// Gets or sets the thumbnail as a <c>byte[]</c> in {@link
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/// Variant#VT_CF VT_CF} format.
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/// </summary>
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/// <value>The thumbnail value</value>
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public byte[] ThumbnailData
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{
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get
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{
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return thumbnailData;
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}
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set { this.thumbnailData = value; }
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}
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/// <summary>
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/// Returns an <c>int</c> representing the Clipboard
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/// Format Tag
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/// Possible return values are:
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/// <ul>
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/// <li>{@link #CFTAG_WINDOWS CFTAG_WINDOWS}</li>
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/// <li>{@link #CFTAG_MACINTOSH CFTAG_MACINTOSH}</li>
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/// <li>{@link #CFTAG_FMTID CFTAG_FMTID}</li>
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/// <li>{@link #CFTAG_NODATA CFTAG_NODATA}</li>
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/// </ul>
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/// </summary>
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/// <returns>A flag indicating the Clipboard Format Tag</returns>
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public long ClipboardFormatTag
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{
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get
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{
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long clipboardFormatTag = LittleEndian.GetUInt(this.ThumbnailData,
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OFFSet_CFTAG);
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return clipboardFormatTag;
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}
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}
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/// <summary>
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/// Returns an <c>int</c> representing the Clipboard
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/// Format
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/// Will throw an exception if the Thumbnail's Clipboard Format
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/// Tag is not {@link Thumbnail#CFTAG_WINDOWS CFTAG_WINDOWS}.
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/// Possible return values are:
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/// <ul>
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/// <li>{@link #CF_METAFILEPICT CF_METAFILEPICT}</li>
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/// <li>{@link #CF_DIB CF_DIB}</li>
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/// <li>{@link #CF_ENHMETAFILE CF_ENHMETAFILE}</li>
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/// <li>{@link #CF_BITMAP CF_BITMAP}</li>
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/// </ul>
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/// </summary>
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/// <returns>a flag indicating the Clipboard Format</returns>
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public long GetClipboardFormat()
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{
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if (!(ClipboardFormatTag == CFTAG_WINDOWS))
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throw new HPSFException("Clipboard Format Tag of Thumbnail must " +
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"be CFTAG_WINDOWS.");
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return LittleEndian.GetUInt(this.ThumbnailData, OFFSet_CF);
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}
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/// <summary>
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/// Returns the Thumbnail as a <c>byte[]</c> of WMF data
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/// if the Thumbnail's Clipboard Format Tag is {@link
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/// #CFTAG_WINDOWS CFTAG_WINDOWS} and its Clipboard Format is
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/// {@link #CF_METAFILEPICT CF_METAFILEPICT}
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/// This
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/// <c>byte[]</c> is in the traditional WMF file, not the
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/// clipboard-specific version with special headers.
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/// See <a href="http://www.wvware.com/caolan/ora-wmf.html" tarGet="_blank">http://www.wvware.com/caolan/ora-wmf.html</a>
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/// for more information on the WMF image format.
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/// @return A WMF image of the Thumbnail
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/// @throws HPSFException if the Thumbnail isn't CFTAG_WINDOWS and
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/// CF_METAFILEPICT
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/// </summary>
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/// <returns></returns>
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public byte[] GetThumbnailAsWMF()
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{
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if (!(ClipboardFormatTag == CFTAG_WINDOWS))
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throw new HPSFException("Clipboard Format Tag of Thumbnail must " +
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"be CFTAG_WINDOWS.");
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if (!(GetClipboardFormat() == CF_METAFILEPICT))
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throw new HPSFException("Clipboard Format of Thumbnail must " +
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"be CF_METAFILEPICT.");
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else
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{
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byte[] thumbnail = this.ThumbnailData;
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int wmfImageLength = thumbnail.Length - OFFSet_WMFDATA;
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byte[] wmfImage = new byte[wmfImageLength];
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Array.Copy(thumbnail,
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OFFSet_WMFDATA,
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wmfImage,
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0,
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wmfImageLength);
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return wmfImage;
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}
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}
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}
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}
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