以前也介绍过PDF打印图片的方法。但是发现了一个问题。用户使用的PDF文件未必都是标准的PDF文件。对于不标准的PDF文件。转换就会失败了。转换出来的图片,空白乱码等效果。研究了几种方法后。觉得还是使用adobe官方的插件来实现吧。所以我选择了使用Acrobat。
需要准备的:下载Adobe Acrobat Professional 9
添加引用:Microsoft.CSharp.dll,Acrobat.dll 和Microsoft.VisualBasic.dll
/// <summary> /// 将PDF文档转换为图片的方法,你可以像这样调用该方法:ConvertPDF2Image("F:\\A.pdf", "F:\\", "A", 0, 0, null, 0); /// 因为大多数的参数都有默认值,startPageNum默认值为1,endPageNum默认值为总页数, /// imageFormat默认值为ImageFormat.Jpeg,resolution默认值为1 /// </summary> /// <param name="pdfInputPath">PDF文件路径</param> /// <param name="imageOutputPath">图片输出路径</param> /// <param name="imageName">图片的名字,不需要带扩展名</param> /// <param name="startPageNum">从PDF文档的第几页开始转换,默认值为1</param> /// <param name="endPageNum">从PDF文档的第几页开始停止转换,默认值为PDF总页数</param> /// <param name="imageFormat">设置所需图片格式</param> /// <param name="resolution">设置图片的分辨率,数字越大越清晰,默认值为1</param> public static void ConvertPDF2Image(string pdfInputPath, string imageOutputPath, string imageName, int startPageNum, int endPageNum, ImageFormat imageFormat, double resolution) { Acrobat.CAcroPDDoc pdfDoc = null; Acrobat.CAcroPDPage pdfPage = null; Acrobat.CAcroRect pdfRect = null; Acrobat.CAcroPoint pdfPoint = null; // Create the document (Can only create the AcroExch.PDDoc object using late-binding) // Note using VisualBasic helper functions, have to add reference to DLL pdfDoc = (Acrobat.CAcroPDDoc)Microsoft.VisualBasic.Interaction.CreateObject("AcroExch.PDDoc", ""); // validate parameter if (!pdfDoc.Open(pdfInputPath)) { throw new FileNotFoundException(); } if (!Directory.Exists(imageOutputPath)) { Directory.CreateDirectory(imageOutputPath); } if (startPageNum <= 0) { startPageNum = 1; } if (endPageNum > pdfDoc.GetNumPages() || endPageNum <= 0) { endPageNum = pdfDoc.GetNumPages(); } if (startPageNum > endPageNum) { int tempPageNum = startPageNum; startPageNum = endPageNum; endPageNum = startPageNum; } if (imageFormat == null) { imageFormat = ImageFormat.Jpeg; } if (resolution <= 0) { resolution = 1; } // start to convert each page for (int i = startPageNum; i <= endPageNum; i++) { pdfPage = (Acrobat.CAcroPDPage)pdfDoc.AcquirePage(i - 1); pdfPoint = (Acrobat.CAcroPoint)pdfPage.GetSize(); pdfRect = (Acrobat.CAcroRect)Microsoft.VisualBasic.Interaction.CreateObject("AcroExch.Rect", ""); int imgWidth = (int)((double)pdfPoint.x * resolution); int imgHeight = (int)((double)pdfPoint.y * resolution); pdfRect.Left = 0; pdfRect.right = (short)imgWidth; pdfRect.Top = 0; pdfRect.bottom = (short)imgHeight; // Render to clipboard, scaled by 100 percent (ie. original size) // Even though we want a smaller image, better for us to scale in .NET // than Acrobat as it would greek out small text pdfPage.CopyToClipboard(pdfRect, 0, 0, (short)(100 * resolution)); IDataObject clipboardData = Clipboard.GetDataObject(); if (clipboardData.GetDataPresent(DataFormats.Bitmap)) { Bitmap pdfBitmap = (Bitmap)clipboardData.GetData(DataFormats.Bitmap); pdfBitmap.Save(Path.Combine(imageOutputPath, imageName) + ".jpg", imageFormat); pdfBitmap.Dispose(); } } pdfDoc.Close(); Marshal.ReleaseComObject(pdfPage); Marshal.ReleaseComObject(pdfRect); Marshal.ReleaseComObject(pdfDoc); Marshal.ReleaseComObject(pdfPoint); }