在本教程中，我们将了解如何使用 C++** 将 PUB) 转换为 PNG。您会注意到转换分两个步骤进行。首先，将 PUB 文件转换为 PDF 文件，然后使用 C++ 通过简单的 API 调用将中间 PDF 文件渲染为 PNG 格式。
使用 C++ 将 PUB 转换为 PNG 的步骤
- 从 NuGet 包管理器工具安装 Aspose.PUB for C++ 和 Aspose.PDF for C++
- 添加对 Aspose::Pub 和 Aspose::Pdf 命名空间的引用
- 使用 Document 类实例加载输入 PUB 文件
- 使用 ConvertToPdf 方法创建中间 PDF 文件
- 迭代每个页面并创建输出 PNG 图像
您可以通过几行代码通过简单的 API 调用使用 C++* 有效地将 PUB 导出为 PNG。您只需要指定文件路径并进行方法调用，然后 API 会自行考虑转换过程的所有次要细节。处理后，根据您的要求保存输出的 PNG 图像。
使用 C++ 将 PUB 转换为 PNG 的代码
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| #pragma once | |
| #include <stdio.h> | |
| #include <tchar.h> | |
| #include <cstdint> | |
| #include <iostream> | |
| // TODO: reference additional headers your program requires here | |
| #include "system/console.h" | |
| #include "system/string.h" | |
| #include "system/io/directory.h" | |
| #include <Aspose.Pub.Cpp/Properties/AssemblyInfo.h> | |
| #include <Aspose.Pub.Cpp/PubFactory.h> | |
| #include <Aspose.Pub.Cpp/Document.h> | |
| #include <Aspose.Pub.Cpp/Interfaces.h> | |
| #include <Aspose.Pub.Cpp/License.h> | |
| #include <Aspose.Pub.Cpp/MetaInfo.h> | |
| #include <Aspose.PDF.Cpp/Page.h> | |
| #include <Aspose.PDF.Cpp/Document.h> | |
| #include <Aspose.PDF.Cpp/PageCollection.h> | |
| #include <Aspose.PDF.Cpp/Resources.h> | |
| #include <Aspose.PDF.Cpp/XImageCollection.h> | |
| #include <Aspose.PDF.Cpp/XImage.h> | |
| #include <Aspose.PDF.Cpp/License.h> | |
| #include <Aspose.PDF.Cpp/License.h> | |
| #include <Aspose.PDF.Cpp/Devices/PngDevice.h> | |
| #include <Aspose.PDF.Cpp/Devices/Resolution.h> | |
| #include <Aspose.PUB.Cpp/License.h> | |
| #include <Aspose.PUB.Cpp/PubFactory.h> | |
| #include <Aspose.PUB.Cpp/Utils/UtilityObjects.h> | |
| #include <system/smart_ptr.h> | |
| using namespace System; | |
| using namespace Aspose::Pdf; | |
| using namespace Aspose::Pub; | |
| class ConvertPUBtoPNGEx { | |
| public: | |
| static void PUBtoPNG() | |
| { | |
| // Initialize license object of Aspose.PUB to convert PUB to PDF | |
| auto PUBlicense = System::MakeObject<Aspose::Pub::License>(); | |
| // Set license | |
| PUBlicense->SetLicense(u"Aspose.Total.NET.lic"); | |
| // Initialize license object of Aspose.PDF API to convert PDF to PNG | |
| auto PDFlicense = System::MakeObject<Aspose::Pdf::License>(); | |
| // Set license | |
| PDFlicense->SetLicense(u"Aspose.Total.NET.lic"); | |
| System::String filePub = u"Sample.pub"; | |
| System::String filePdf = u"Test.pdf"; | |
| System::SharedPtr<IPubParser> parser = PubFactory::CreateParser(filePub); | |
| System::SharedPtr<Aspose::Pub::Document> document = parser->Parse(); | |
| PubFactory::CreatePdfConverter()->ConvertToPdf(document, filePdf); | |
| // Load the intermediate PDF file created from PUB file | |
| System::SharedPtr<Aspose::Pdf::Document> pdfDocument = MakeObject<Aspose::Pdf::Document>(filePdf); | |
| // Iterate throught the PDF pages for image conversion | |
| for (System::SharedPtr<Page> page : pdfDocument->get_Pages()) | |
| { | |
| // Create an instance of the FileStream class for output PNG image | |
| System::SharedPtr<System::IO::FileStream> imageStream = System::IO::File::Create(String::Format(u"page_{0}.png", page->get_Number())); | |
| // Create an instance of the Resolution class to set resolution of PNG | |
| System::SharedPtr<Aspose::Pdf::Devices::Resolution> resolution = MakeObject<Aspose::Pdf::Devices::Resolution>(300); | |
| // Create an instance of the PngDevice class to render images | |
| System::SharedPtr<Aspose::Pdf::Devices::PngDevice> pngDevice = MakeObject<Aspose::Pdf::Devices::PngDevice>(500, 700, resolution); | |
| // Save the page as PNG image output | |
| pngDevice->Process(page, imageStream); | |
| // Close the stream | |
| imageStream->Close(); | |
| } | |
| } | |
| }; |
在上一主题中，我们学习了 如何在 C++ 中读取 PDF 文件。然而，在本文中，我们讨论了如何使用 C++ 从 PUB 文件创建 PNG。
