C# PDF转为图片的方法

用ghostscript免费组件实现,把gsdll32.dll 复制到自己项目的debug文件夹下(跟最终的exe文件同一目录)
gsdll32.dll下载地址：http://download.csdn.net/download/qq_29098553/9977722

添加一个PDFConvert类：
using System;
using System.Collections.Generic;
using System.Text;
using System.Runtime.InteropServices;
using System.Collections;
using System.IO;

namespace PdfToImage
{
///
/// Create by : TaGoH
/// URL of the last version: http://www.codeproject.com/KB/cs/GhostScriptUseWithCSharp.aspx
/// Description:
/// Class to convert a pdf to an image using GhostScript DLL
/// A big Credit for this code go to:Rangel Avulso he made me start with the project!
///
///
///
public class PDFConvert
{
#region Static
/// The name of the DLL i’m using to work
public const string GhostScriptDLLName = “gsdll32.dll”;
/// Use to check for default transformation
private static bool useSimpleAnsiConversion = true;
/// Thanks to tchu_2000 to remind that u should never hardcode strings! :)
private const string GS_OutputFileFormat = “-sOutputFile={0}”;
private const string GS_DeviceFormat = “-sDEVICE={0}”;
private const string GS_FirstParameter = “pdf2img”;
private const string GS_ResolutionXFormat = “-r{0}”;
private const string GS_ResolutionXYFormat = “-r{0}x{1}”;
private const string GS_GraphicsAlphaBits = “-dGraphicsAlphaBits={0}”;
private const string GS_TextAlphaBits = “-dTextAlphaBits={0}”;
private const string GS_FirstPageFormat = “-dFirstPage={0}”;
private const string GS_LastPageFormat = “-dLastPage={0}”;
private const string GS_FitPage = “-dPDFFitPage”;
private const string GS_PageSizeFormat = “-g{0}x{1}”;
private const string GS_DefaultPaperSize = “-sPAPERSIZE={0}”;
private const string GS_JpegQualityFormat = “-dJPEGQ={0}”;
private const string GS_RenderingThreads = “-dNumRenderingThreads={0}”;
private const string GS_Fixed1stParameter = “-dNOPAUSE”;
private const string GS_Fixed2ndParameter = “-dBATCH”;
private const string GS_Fixed3rdParameter = “-dSAFER”;
private const string GS_FixedMedia = “-dFIXEDMEDIA”;
private const string GS_QuiteOperation = “-q”;
private const string GS_StandardOutputDevice = “-“;
private const string GS_MultiplePageCharacter = “%”;
//Thanks to davalv for this font related options
//http://www.codeproject.com/script/Membership/View.aspx?mid=3255201
private const string GS_FontPath = “-sFONTPATH={0}”;
private const string GS_NoPlatformFonts = “-dNOPLATFONTS”;
private const string GS_NoFontMap = “-dNOFONTMAP”;
private const string GS_FontMap = “-sFONTMAP={0}”;
private const string GS_SubstitutionFont = “-sSUBSTFONT={0}”;
private const string GS_FCOFontFile = “-sFCOfontfile={0}”;
private const string GS_FAPIFontMap = “-sFAPIfontmap={0}”;
private const string GS_NoPrecompiledFonts = “-dNOCCFONTS”;
/// Mutex used to be sure that the DLL is not called twice
private static System.Threading.Mutex mutex;
#endregion
#region Windows Import
/// Needed to copy memory from one location to another, used to fill the struct
///
///
///
[DllImport(“kernel32.dll”, EntryPoint = “RtlMoveMemory”)]
static extern void CopyMemory(IntPtr Destination, IntPtr Source, uint Length);
#endregion
#region GhostScript Import

    /// <summary>Create a new instance of Ghostscript. This instance is passed to most other gsapi functions. The caller_handle will be provided to callback functions.///  At this stage, Ghostscript supports only one instance. </summary>/// <param name="pinstance"></param>/// <param name="caller_handle"></param>/// <returns></returns>[DllImport(GhostScriptDLLName, EntryPoint = "gsapi_new_instance")]private static extern int gsapi_new_instance(out IntPtr pinstance, IntPtr caller_handle);/// <summary>This is the important function that will perform the conversion</summary>/// <param name="instance"></param>/// <param name="argc"></param>/// <param name="argv"></param>/// <returns></returns>[DllImport("gsdll32.dll", EntryPoint = "gsapi_init_with_args")]private static extern int gsapi_init_with_args(IntPtr instance, int argc, IntPtr argv);/// <summary>/// Exit the interpreter. This must be called on shutdown if gsapi_init_with_args() has been called, and just before gsapi_delete_instance(). /// </summary>/// <param name="instance"></param>/// <returns></returns>[DllImport("gsdll32.dll", EntryPoint = "gsapi_exit")]private static extern int gsapi_exit(IntPtr instance);/// <summary>/// Destroy an instance of Ghostscript. Before you call this, Ghostscript must have finished. If Ghostscript has been initialised, you must call gsapi_exit before gsapi_delete_instance. /// </summary>/// <param name="instance"></param>[DllImport("gsdll32.dll", EntryPoint = "gsapi_delete_instance")]private static extern void gsapi_delete_instance(IntPtr instance);/// <summary>Get info about the version of Ghostscript i'm using</summary>/// <param name="pGSRevisionInfo"></param>/// <param name="intLen"></param>/// <returns></returns>[DllImport("gsdll32.dll", EntryPoint = "gsapi_revision")]private static extern int gsapi_revision(ref GS_Revision pGSRevisionInfo, int intLen);/// <summary>Use a different I/O</summary>/// <param name="lngGSInstance"></param>/// <param name="gsdll_stdin">Function that menage the Standard INPUT</param>/// <param name="gsdll_stdout">Function that menage the Standard OUTPUT</param>/// <param name="gsdll_stderr">Function that menage the Standard ERROR output</param>/// <returns></returns>[DllImport("gsdll32.dll", EntryPoint = "gsapi_set_stdio")]private static extern int gsapi_set_stdio(IntPtr lngGSInstance, StdioCallBack gsdll_stdin, StdioCallBack gsdll_stdout, StdioCallBack gsdll_stderr);#endregion#region Constconst int e_Quit = -101;const int e_NeedInput = -106;#endregion#region Variablesprivate string _sDeviceFormat;private string _sParametersUsed;private int _iWidth;private int _iHeight;private int _iResolutionX;private int _iResolutionY;private int _iJPEGQuality;/// <summary>The first page to convert in image</summary>private int _iFirstPageToConvert = -1;/// <summary>The last page to conver in an image</summary>private int _iLastPageToConvert = -1;/// <summary>This parameter is used to control subsample antialiasing of graphics</summary>private int _iGraphicsAlphaBit = -1;/// <summary>This parameter is used to control subsample antialiasing of text</summary>private int _iTextAlphaBit = -1;/// <summary>In how many thread i should perform the conversion</summary>/// <remarks>This is a Major innovation since 8.63 NEVER use it with previous version!</remarks>private int _iRenderingThreads = -1;/// <summary>In how many thread i should perform the conversion</summary>/// <remarks>This is a Major innovation since 8.63 NEVER use it with previous version!</remarks>/// <value>Set it to 0 made the program set it to Environment.ProcessorCount HT machine could want to perform a check for this..</value>public int RenderingThreads{get { return _iRenderingThreads; }set{if (value == 0)_iRenderingThreads = Environment.ProcessorCount;else_iRenderingThreads = value;}}private bool _bFitPage;private bool _bThrowOnlyException = false;private bool _bRedirectIO = false;private bool _bForcePageSize = false;/// <summary>The pagesize of the output</summary>private string _sDefaultPageSize;private IntPtr _objHandle;/// <summary>If true i will try to output everypage to a different file!</summary>private bool _didOutputToMultipleFile = false;private System.Diagnostics.Process myProcess;public StringBuilder output;//public string output;//private List<byte> outputBytes;//public string error;#region Fonts related variables thanks to devalvprivate List<string> _sFontPath = new List<string>();private bool _bDisablePlatformFonts = false;private bool _bDisableFontMap = false;private List<string> _sFontMap = new List<string>();private string _sSubstitutionFont;private string _sFCOFontFile;private string _sFAPIFontMap;private bool _bDisablePrecompiledFonts = false;#endregion#endregion#region Proprieties/// <summary>/// What format to use to convert/// is suggested to use png256 instead of jpeg for document!/// they are smaller and better suited!/// </summary>/// <see cref="http://pages.cs.wisc.edu/~ghost/doc/cvs/Devices.htm"/>public string OutputFormat{get { return _sDeviceFormat; }set { _sDeviceFormat = value; }}/// <summary>The pagesize of the output</summary>/// <remarks>Without this parameter the output should be letter, complain to USA for this :) if the document specify a different size it will take precedece over this!</remarks>/// <see cref="http://pages.cs.wisc.edu/~ghost/doc/cvs/Use.htm#Known_paper_sizes"/>public string DefaultPageSize{get { return _sDefaultPageSize; }set { _sDefaultPageSize = value; }}/// <summary>If set to true and page default page size will force the rendering in that output format</summary>public bool ForcePageSize{get { return _bForcePageSize; }set { _bForcePageSize = value; }}public string ParametersUsed{get { return _sParametersUsed; }set { _sParametersUsed = value; }}public int Width{get { return _iWidth; }set { _iWidth = value; }}public int Height{get { return _iHeight; }set { _iHeight = value; }}public int ResolutionX{get { return _iResolutionX; }set { _iResolutionX = value; }}public int ResolutionY{get { return _iResolutionY; }set { _iResolutionY = value; }}/// <summary>This parameter is used to control subsample antialiasing of graphics</summary>/// <value>Value MUST BE below or equal 0 if not set, or 1,2,or 4 NO OTHER VALUES!</value>/// <see cref="http://pages.cs.wisc.edu/~ghost/doc/cvs/Use.htm"/>public int GraphicsAlphaBit{get { return _iGraphicsAlphaBit; }set{if ((value > 4) | (value == 3))throw new ArgumentOutOfRangeException("The Graphics Alpha Bit must have a value between 1 2 and 4, or <= 0 if not set");_iGraphicsAlphaBit = value;}}/// <summary>This parameter is used to control subsample antialiasing of text</summary>/// <value>Value MUST BE below or equal 0 if not set, or 1,2,or 4 NO OTHER VALUES!</value>/// <see cref="http://pages.cs.wisc.edu/~ghost/doc/cvs/Use.htm"/>public int TextAlphaBit{get { return _iTextAlphaBit; }set{if ((value > 4) | (value == 3))throw new ArgumentOutOfRangeException("The Text Alpha Bit must have a value between 1 2 and 4, or <= 0 if not set");_iTextAlphaBit = value;}}public Boolean FitPage{get { return _bFitPage; }set { _bFitPage = value; }}/// <summary>Quality of compression of JPG</summary>public int JPEGQuality{get { return _iJPEGQuality; }set { _iJPEGQuality = value; }}/// <summary>The first page to convert in image</summary>public int FirstPageToConvert{get { return _iFirstPageToConvert; }set { _iFirstPageToConvert = value; }}/// <summary>The last page to conver in an image</summary>public int LastPageToConvert{get { return _iLastPageToConvert; }set { _iLastPageToConvert = value; }}/// <summary>Set to True if u want the program to never display Messagebox/// but otherwise throw exception</summary>public Boolean ThrowOnlyException{get { return _bThrowOnlyException; }set { _bThrowOnlyException = value; }}/// <summary>[NOT WORKING]If i should redirect the Output of Ghostscript library somewhere</summary>/// <remarks>NOT WORKING!!!</remarks>public bool RedirectIO{get { return _bRedirectIO; }set { _bRedirectIO = value; }}/// <summary>If true i will try to output everypage to a different file!</summary>public bool OutputToMultipleFile{get { return _didOutputToMultipleFile; }set { _didOutputToMultipleFile = value; }}/// <summary>/// If set to true the library will use a mutex to be sure that the library is never called twice at the same time!/// </summary>public bool UseMutex{get { return mutex != null; }set{if (!value)//if i don't want to use it{if (mutex != null)//if it exist{   //close and delete itmutex.ReleaseMutex();mutex.Close();mutex = null;}}else//If i want to use mutex create it if it doesn't exist{if (mutex == null)mutex = new System.Threading.Mutex(false, "MutexGhostscript");}}}#region Fonts related thanks to devalvpublic List<string> FontPath{get { return _sFontPath; }set { _sFontPath = value; }}public bool DisablePlatformFonts{get { return _bDisablePlatformFonts; }set { _bDisablePlatformFonts = value; }}public bool DisableFontMap{get { return _bDisableFontMap; }set { _bDisableFontMap = value; }}public List<string> FontMap{get { return _sFontMap; }set { _sFontMap = value; }}public string SubstitutionFont{get { return _sSubstitutionFont; }set { _sSubstitutionFont = value; }}public string FCOFontFile{get { return _sFCOFontFile; }set { _sFCOFontFile = value; }}public string FAPIFontMap{get { return _sFAPIFontMap; }set { _sFAPIFontMap = value; }}public bool DisablePrecompiledFonts{get { return _bDisablePrecompiledFonts; }set { _bDisablePrecompiledFonts = value; }}#endregion#endregion#region Initpublic PDFConvert(IntPtr objHandle){_objHandle = objHandle;}public PDFConvert(){_objHandle = IntPtr.Zero;}#endregion#region Convert/// <summary>Convert a single file!</summary>/// <param name="inputFile">The file PDf to convert</param>/// <param name="outputFile">The image file that will be created</param>/// <remarks>You must pass all the parameter for the conversion/// as Proprieties of this class</remarks>/// <returns>True if the conversion succed!</returns>public bool Convert(string inputFile, string outputFile){return Convert(inputFile, outputFile, _bThrowOnlyException, null);}/// <summary>Convert a single file!</summary>/// <param name="inputFile">The file PDf to convert</param>/// <param name="outputFile">The image file that will be created</param>/// <param name="parameters">You must pass all the parameter for the conversion here</param>/// <remarks>Thanks to     tchu_2000 for the help!</remarks>/// <returns>True if the conversion succed!</returns>public bool Convert(string inputFile, string outputFile, string parameters){return Convert(inputFile, outputFile, _bThrowOnlyException, parameters);}/// <summary>Convert a single file!</summary>/// <param name="inputFile">The file PDf to convert</param>/// <param name="outputFile">The image file that will be created</param>/// <param name="throwException">if the function should throw an exception/// or display a message box</param>/// <remarks>You must pass all the parameter for the conversion/// as Proprieties of this class</remarks>/// <returns>True if the conversion succed!</returns>private bool Convert(string inputFile, string outputFile, bool throwException, string options){#region Check Input//Avoid to work when the file doesn't existif (string.IsNullOrEmpty(inputFile))throw new ArgumentNullException("inputFile");if (!System.IO.File.Exists(inputFile))throw new ArgumentException(string.Format("The file :'{0}' doesn't exist", inputFile), "inputFile");if (string.IsNullOrEmpty(_sDeviceFormat))throw new ArgumentNullException("Device");//be sure that if i specify multiple page outpage i added the % to the filename!#endregion//If i create a Mutex it means i want to protect concurrent access to the libraryif (mutex != null) mutex.WaitOne();bool result = false;try{result = ExecuteGhostscriptCommand(GetGeneratedArgs(inputFile, outputFile, options));}finally { if (mutex != null) mutex.ReleaseMutex(); }return result;}/// <summary>Print a file</summary>/// <param name="inputFile">THe file to print</param>/// <param name="printParametersFile">The file with the configuration of the printer</param>/// <returns>True if i send the work to the printer queue</returns>public bool Print(string inputFile, string printParametersFile){#region Check Input//Avoid to work when the file doesn't existif (string.IsNullOrEmpty(inputFile))throw new ArgumentNullException("inputFile");if (!System.IO.File.Exists(inputFile))throw new ArgumentException(string.Format("The file :'{0}' doesn't exist", inputFile), "inputFile");//Avoid to work when the file doesn't existif (string.IsNullOrEmpty(printParametersFile))throw new ArgumentNullException("printParametersFile");if (!System.IO.File.Exists(printParametersFile))throw new ArgumentException(string.Format("The file :'{0}' doesn't exist", printParametersFile), "printParametersFile");#endregion// Example : gswin32.exe" -dNOPAUSE -dBATCH -dFirstPage=1 -dLastPage=1 setup.ps mio.pdf -c quitList<string> args = new List<string>(7);args.Add("printPdf");args.Add("-dNOPAUSE");args.Add("-dBATCH");if (_iFirstPageToConvert > 0)args.Add(string.Format("-dFirstPage={0}", _iFirstPageToConvert));if ((_iLastPageToConvert > 0) && (_iLastPageToConvert >= _iFirstPageToConvert))args.Add(string.Format("-dLastPage={0}", _iLastPageToConvert));args.Add(printParametersFile);args.Add(inputFile);bool result = false;if (mutex != null) mutex.WaitOne();try { result = ExecuteGhostscriptCommand(args.ToArray()); }finally { if (mutex != null) mutex.ReleaseMutex(); }return result;}/// <summary>Execute a Ghostscript command with a certain list of arguments</summary>/// <param name="sArgs">The list of the arguments</param>/// <returns>true if it succed, false otherwise</returns>private bool ExecuteGhostscriptCommand(string[] sArgs){#region Variablesint intReturn, intCounter, intElementCount;//The pointer to the current istance of the dllIntPtr intGSInstanceHandle = IntPtr.Zero;object[] aAnsiArgs;IntPtr[] aPtrArgs;GCHandle[] aGCHandle;IntPtr callerHandle, intptrArgs;GCHandle gchandleArgs;#endregion#region Convert Unicode strings to null terminated ANSI byte arrays// Convert the Unicode strings to null terminated ANSI byte arrays// then get pointers to the byte arrays.intElementCount = sArgs.Length;aAnsiArgs = new object[intElementCount];aPtrArgs = new IntPtr[intElementCount];aGCHandle = new GCHandle[intElementCount];//Convert the parametersfor (intCounter = 0; intCounter < intElementCount; intCounter++){aAnsiArgs[intCounter] = StringToAnsiZ(sArgs[intCounter]);aGCHandle[intCounter] = GCHandle.Alloc(aAnsiArgs[intCounter], GCHandleType.Pinned);aPtrArgs[intCounter] = aGCHandle[intCounter].AddrOfPinnedObject();}gchandleArgs = GCHandle.Alloc(aPtrArgs, GCHandleType.Pinned);intptrArgs = gchandleArgs.AddrOfPinnedObject();#endregion#region Create a new istance of the library!intReturn = -1;try{intReturn = gsapi_new_instance(out intGSInstanceHandle, _objHandle);//Be sure that we create an istance!if (intReturn < 0){ClearParameters(ref aGCHandle, ref gchandleArgs);throw new ApplicationException("I can't create a new istance of Ghostscript please verify no other istance are running!");}}catch (BadImageFormatException formatException)//99.9% of time i'm just loading a 32bit dll in a 64bit enviroment!{ClearParameters(ref aGCHandle, ref gchandleArgs);//Check if i'm in a 64bit enviroment or a 32bitif (IntPtr.Size == 8) // 8 * 8 = 64{throw new ApplicationException(string.Format("The gsdll32.dll you provide is not compatible with the current architecture that is 64bit," +"Please download any version above version 8.64 from the original website in the 64bit or x64 or AMD64 version!"));}else if (IntPtr.Size == 4) // 4 * 8 = 32{throw new ApplicationException(string.Format("The gsdll32.dll you provide is not compatible with the current architecture that is 32bit," +"Please download any version above version 8.64 from the original website in the 32bit or x86 or i386 version!"));}}catch (DllNotFoundException ex)//in this case the dll we r using isn't the dll we expect{ClearParameters(ref aGCHandle, ref gchandleArgs);throw new ApplicationException("The gsdll32.dll wasn't found in default dlls search path" +"or is not in correct version (doesn't expose the required methods). Please download " +"at least the version 8.64 from the original website");}callerHandle = IntPtr.Zero;//remove unwanter handler#endregion#region Capture the I/O//Not workingif (_bRedirectIO){StdioCallBack stdinCallback = new StdioCallBack(gsdll_stdin);StdioCallBack stdoutCallback = new StdioCallBack(gsdll_stdout);StdioCallBack stderrCallback = new StdioCallBack(gsdll_stderr);intReturn = gsapi_set_stdio(intGSInstanceHandle, stdinCallback, stdoutCallback, stderrCallback);if (output == null) output = new StringBuilder();else output.Remove(0, output.Length);myProcess = System.Diagnostics.Process.GetCurrentProcess();myProcess.OutputDataReceived += new System.Diagnostics.DataReceivedEventHandler(SaveOutputToImage);}#endregionintReturn = -1;//if nothing change it there is an error!//Ok now is time to call the interesting methodtry { intReturn = gsapi_init_with_args(intGSInstanceHandle, intElementCount, intptrArgs); }catch (Exception ex){throw new ApplicationException(ex.Message, ex);}finally//No matter what happen i MUST close the istance!{   //free all the memoryClearParameters(ref aGCHandle, ref gchandleArgs);gsapi_exit(intGSInstanceHandle);//Close the istancegsapi_delete_instance(intGSInstanceHandle);//delete it//In case i was looking for output now stopif ((myProcess != null) && (_bRedirectIO)) myProcess.OutputDataReceived -= new System.Diagnostics.DataReceivedEventHandler(SaveOutputToImage);}//Conversion was successfull if return code was 0 or e_Quitreturn (intReturn == 0) | (intReturn == e_Quit);//e_Quit = -101}/// <summary>Remove the memory allocated</summary>/// <param name="aGCHandle"></param>/// <param name="gchandleArgs"></param>private void ClearParameters(ref GCHandle[] aGCHandle, ref GCHandle gchandleArgs){for (int intCounter = 0; intCounter < aGCHandle.Length; intCounter++)aGCHandle[intCounter].Free();gchandleArgs.Free();}#region Test (code not used)void SaveOutputToImage(object sender, System.Diagnostics.DataReceivedEventArgs e){output.Append(e.Data);}//public System.Drawing.Image Convert(string inputFile)//{//    _bRedirectIO = true;//    if (Convert(inputFile, "%stdout", _bThrowOnlyException))//    {//        if ((output != null) && (output.Length > 0))//        {//            //StringReader sr = new StringReader(output.ToString());//            //MemoryStream ms = new MemoryStream(UTF8Encoding.Default.GetBytes(output.ToString()));//            System.Drawing.Image returnImage = System.Drawing.Image.FromStream(myProcess.StandardOutput.BaseStream).Clone() as System.Drawing.Image;//            //ms.Close();//            return returnImage;//        }//    }//    return null;//}#endregion#endregion#region Accessory Functions/// <summary>This function create the list of parameters to pass to the dll with parameters given directly from the program</summary>/// <param name="inputFile"></param>/// <param name="outputFile"></param>/// <param name="otherParameters">The other parameters i could be interested</param>/// <remarks>Be very Cautious using this! code provided and modified from tchu_2000</remarks>/// <returns></returns>private string[] GetGeneratedArgs(string inputFile, string outputFile, string otherParameters){if (!string.IsNullOrEmpty(otherParameters))return GetGeneratedArgs(inputFile, outputFile, otherParameters.Split(new string[] { " " }, StringSplitOptions.RemoveEmptyEntries));elsereturn GetGeneratedArgs(inputFile, outputFile, (string[])null);}/// <summary>This function create the list of parameters to pass to the dll</summary>/// <param name="inputFile">the file to convert</param>/// <param name="outputFile">where to write the image</param>/// <returns>the list of the arguments</returns>private string[] GetGeneratedArgs(string inputFile, string outputFile, string[] presetParameters){string[] args;ArrayList lstExtraArgs = new ArrayList();//ok if i haven't been passed a list of parameters create my ownif ((presetParameters == null) || (presetParameters.Length == 0)){#region Parameters//Ok now check argument per argument and compile them//If i want a jpeg i can set also qualityif (_sDeviceFormat == "jpeg" && _iJPEGQuality > 0 && _iJPEGQuality < 101)lstExtraArgs.Add(string.Format(GS_JpegQualityFormat, _iJPEGQuality));//if i provide size it will override the paper sizeif (_iWidth > 0 && _iHeight > 0)lstExtraArgs.Add(string.Format(GS_PageSizeFormat, _iWidth, _iHeight));else//otherwise if aviable use the papersize{if (!string.IsNullOrEmpty(_sDefaultPageSize)){lstExtraArgs.Add(string.Format(GS_DefaultPaperSize, _sDefaultPageSize));//It have no meaning to set it if the default page is not set!if (_bForcePageSize)lstExtraArgs.Add(GS_FixedMedia);}}//not set antialiasing settingsif (_iGraphicsAlphaBit > 0)lstExtraArgs.Add(string.Format(GS_GraphicsAlphaBits, _iGraphicsAlphaBit));if (_iTextAlphaBit > 0)lstExtraArgs.Add(string.Format(GS_TextAlphaBits, _iTextAlphaBit));//Should i try to fit?if (_bFitPage) lstExtraArgs.Add(GS_FitPage);//Do i have a forced resolution?if (_iResolutionX > 0){if (_iResolutionY > 0)lstExtraArgs.Add(String.Format(GS_ResolutionXYFormat, _iResolutionX, _iResolutionY));elselstExtraArgs.Add(String.Format(GS_ResolutionXFormat, _iResolutionX));}if (_iFirstPageToConvert > 0)lstExtraArgs.Add(String.Format(GS_FirstPageFormat, _iFirstPageToConvert));if (_iLastPageToConvert > 0){if ((_iFirstPageToConvert > 0) && (_iFirstPageToConvert > _iLastPageToConvert))throw new ArgumentOutOfRangeException(string.Format("The 1st page to convert ({0}) can't be after then the last one ({1})", _iFirstPageToConvert, _iLastPageToConvert));lstExtraArgs.Add(String.Format(GS_LastPageFormat, _iLastPageToConvert));}//Set in how many threads i want to do the workif (_iRenderingThreads > 0)lstExtraArgs.Add(String.Format(GS_RenderingThreads, _iRenderingThreads));//If i want to redirect write it to the standard output!if (_bRedirectIO){//In this case you must also use the -q switch to prevent Ghostscript//from writing messages to standard output which become//mixed with the intended output stream. //outputFile = GS_StandardOutputDevice;//lstExtraArgs.Add(GS_QuiteOperation);}#region Fontsif ((_sFontPath != null) && (_sFontPath.Count > 0))lstExtraArgs.Add(String.Format(GS_FontPath, String.Join(";", _sFontPath.ToArray())));if (_bDisablePlatformFonts)lstExtraArgs.Add(GS_NoPlatformFonts);if (_bDisableFontMap)lstExtraArgs.Add(GS_NoFontMap);if ((_sFontMap != null) && (_sFontMap.Count > 0))lstExtraArgs.Add(String.Format(GS_FontMap, String.Join(";", _sFontMap.ToArray())));if (!string.IsNullOrEmpty(_sSubstitutionFont))lstExtraArgs.Add(string.Format(GS_SubstitutionFont, _sSubstitutionFont));if (!string.IsNullOrEmpty(_sFCOFontFile))lstExtraArgs.Add(string.Format(GS_FCOFontFile, _sFCOFontFile));if (!string.IsNullOrEmpty(_sFAPIFontMap)){lstExtraArgs.Add(string.Format(GS_FAPIFontMap, _sFAPIFontMap));}if (_bDisablePrecompiledFonts)lstExtraArgs.Add(GS_NoPrecompiledFonts);#endregion#endregionint iFixedCount = 7;//This are the mandatory optionsint iExtraArgsCount = lstExtraArgs.Count;args = new string[iFixedCount + lstExtraArgs.Count];args[1] = GS_Fixed1stParameter;//"-dNOPAUSE";//I don't want interruptionsargs[2] = GS_Fixed2ndParameter;//"-dBATCH";//stop afterargs[3] = GS_Fixed3rdParameter;//"-dSAFER";args[4] = string.Format(GS_DeviceFormat, _sDeviceFormat);//what kind of export format i should provide//For a complete list watch here://http://pages.cs.wisc.edu/~ghost/doc/cvs/Devices.htm//Fill the remaining parametersfor (int i = 0; i < iExtraArgsCount; i++)args[5 + i] = (string)lstExtraArgs[i];}else{//3 arguments MUST be added 0 (meaningless) and at the end the output and the inputfileargs = new string[presetParameters.Length + 3];//now use the parameters i receive (thanks CrucialBT to point this out!)//and thanks to Barbara who pointout that i was skipping the last parameterfor (int i = 1; i <= presetParameters.Length; i++)args[i] = presetParameters[i - 1];}args[0] = GS_FirstParameter;//this parameter have little real use//Now check if i want to update to 1 file per page i have to be sure do add % to the output filenameif ((_didOutputToMultipleFile) && (!outputFile.Contains(GS_MultiplePageCharacter))){// Thanks to Spillie to show me the error!int lastDotIndex = outputFile.LastIndexOf('.');if (lastDotIndex > 0)outputFile = outputFile.Insert(lastDotIndex, "%d");}//Ok now save them to be shown 4 debug use_sParametersUsed = string.Empty;//Copy all the args except the 1st that is useless and the last 2for (int i = 1; i < args.Length - 2; i++)_sParametersUsed += " " + args[i];//Fill outputfile and inputfile as last 2 arguments!args[args.Length - 2] = string.Format(GS_OutputFileFormat, outputFile);args[args.Length - 1] = string.Format("{0}", inputFile);_sParametersUsed += " " + string.Format(GS_OutputFileFormat, string.Format("\"{0}\"", outputFile))+ " " + string.Format("\"{0}\"", inputFile);return args;}/// <summary>/// Convert a Unicode string to a null terminated Ansi string for Ghostscript./// The result is stored in a byte array/// </summary>/// <param name="str">The parameter i want to convert</param>/// <returns>the byte array that contain the string</returns>private static byte[] StringToAnsiZ(string str){   //This with Encoding.Default should work also with Chineese Japaneese//Thanks to tchu_2000 I18N related patchif (str == null) str = String.Empty;return Encoding.Default.GetBytes(str);}/// <summary>Convert a Pointer to a string to a real string</summary>/// <param name="strz">the pointer to the string in memory</param>/// <returns>The string</returns>public static string AnsiZtoString(IntPtr strz){if (strz != IntPtr.Zero)return Marshal.PtrToStringAnsi(strz);elsereturn string.Empty;}/// <summary>Check if i find the DLL that i need to continue!</summary>/// <returns>true if i found it</returns>public static bool CheckDll(){return File.Exists(GhostScriptDLLName);}#endregion#region Menage Standard Input & Standard Outputpublic int gsdll_stdin(IntPtr intGSInstanceHandle, IntPtr strz, int intBytes){// This is dumb code that reads one byte at a time// Ghostscript doesn't mind this, it is just very slowif (intBytes == 0)return 0;else{int ich = Console.Read();if (ich == -1)return 0; // EOFelse{byte bch = (byte)ich;GCHandle gcByte = GCHandle.Alloc(bch, GCHandleType.Pinned);IntPtr ptrByte = gcByte.AddrOfPinnedObject();CopyMemory(strz, ptrByte, 1);ptrByte = IntPtr.Zero;gcByte.Free();return 1;}}}public int gsdll_stdout(IntPtr intGSInstanceHandle, IntPtr strz, int intBytes){// If you can think of a more efficient method, please tell me!// We need to convert from a byte buffer to a string// First we create a byte array of the appropriate sizebyte[] aByte = new byte[intBytes];// Then we get the address of the byte arrayGCHandle gcByte = GCHandle.Alloc(aByte, GCHandleType.Pinned);IntPtr ptrByte = gcByte.AddrOfPinnedObject();// Then we copy the buffer to the byte arrayCopyMemory(ptrByte, strz, (uint)intBytes);// Release the address lockingptrByte = IntPtr.Zero;gcByte.Free();// Then we copy the byte array to a string, character by characterstring str = "";for (int i = 0; i < intBytes; i++){str += (char)aByte[i];}// Finally we output the message//Console.Write(str);output.Append(str);return intBytes;//if (intBytes > 0)//{//    Console.Write(Marshal.PtrToStringAnsi(strz));//}//return 0;}public int gsdll_stderr(IntPtr intGSInstanceHandle, IntPtr strz, int intBytes){return gsdll_stdout(intGSInstanceHandle, strz, intBytes);//Console.Write(Marshal.PtrToStringAnsi(strz));//return intBytes;}#endregion#region Menage Revisionpublic GhostScriptRevision GetRevision(){// Check revision number of Ghostscriptint intReturn;GS_Revision udtGSRevInfo = new GS_Revision();GhostScriptRevision output;GCHandle gcRevision;gcRevision = GCHandle.Alloc(udtGSRevInfo, GCHandleType.Pinned);intReturn = gsapi_revision(ref udtGSRevInfo, 16);output.intRevision = udtGSRevInfo.intRevision;output.intRevisionDate = udtGSRevInfo.intRevisionDate;output.ProductInformation = AnsiZtoString(udtGSRevInfo.strProduct);output.CopyrightInformations = AnsiZtoString(udtGSRevInfo.strCopyright);gcRevision.Free();return output;}#endregion
}/// <summary>Delegate used by Ghostscript to perform I/O operations</summary>
/// <param name="handle"></param>
/// <param name="strptr"></param>
/// <param name="count"></param>
/// <returns></returns>
public delegate int StdioCallBack(IntPtr handle, IntPtr strptr, int count);/// <summary>This struct is filled with the information of the version of this ghostscript</summary>
/// <remarks>Have the layout defined cuz i will fill it with a kernel copy memory</remarks>
[StructLayout(LayoutKind.Sequential)]
struct GS_Revision
{public IntPtr strProduct;public IntPtr strCopyright;public int intRevision;public int intRevisionDate;
}public struct GhostScriptRevision
{public string ProductInformation;public string CopyrightInformations;public int intRevision;public int intRevisionDate;
}

}

调用这个类
private void Form1_Load(object sender, EventArgs e)
{
ConvertSingleImage(“d:\b.pdf”);
}

private bool ConvertSingleImage(string filename)
{
var converter = new PdfToImage.PDFConvert();
//Setup the converter
converter.OutputToMultipleFile = true;
converter.FirstPageToConvert = -1;
converter.LastPageToConvert = -1;
converter.FitPage = true;
converter.JPEGQuality = 10;
converter.OutputFormat = “png16m”;
System.IO.FileInfo input = new FileInfo(filename);
string output = string.Format(“{0}\{1}{2}”, input.Directory, input.Name, “.png”);
//If the output file exist alrady be sure to add a random name at the end until is unique!
while (File.Exists(output))
{
output = output.Replace(“.png”, string.Format(“{1}{0}”, “.png”, DateTime.Now.Ticks));
}
return converter.Convert(input.FullName, output);
}

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