LibreOffice net core 中怎么使用将pptx 转 pdf

在 LibreOffice net core 中，可以使用 UNO API 来将 pptx 文件转换为 pdf。以下是示例代码：

using System;
using System.IO;
using unoidl.com.sun.star.beans;
using unoidl.com.sun.star.bridge;
using unoidl.com.sun.star.frame;
using unoidl.com.sun.star.lang;
using unoidl.com.sun.star.uno;
using uno.util;

namespace PptxToPdfConverter
{
    class Program
    {
        static void Main(string[] args)
        {
            string inputFile = "test.pptx";
            string outputFile = "test.pdf";

            // initialize the UNO runtime
            var xLocalContext = Bootstrap.bootstrap();
            var xRemoteFactory = (XMultiServiceFactory)xLocalContext.getServiceManager();

            // create a new instance of LibreOffice
            var xComponentContext = (XComponentContext)xRemoteFactory.createInstance("com.sun.star.uno.XComponentContext");
            var xConnector = (XConnector)xRemoteFactory.createInstance("com.sun.star.connection.Connector");
            var xConnection = xConnector.connect("socket,host=localhost,port=2083");
            var xBridgeFactory = (XBridgeFactory)xRemoteFactory.createInstance("com.sun.star.bridge.BridgeFactory");
            var xBridge = xBridgeFactory.createBridge("", "urp", "socket,host=localhost,port=2083", xComponentContext);
            var xRemoteServiceManager = (XMultiServiceFactory)xBridge.getInstance("StarOffice.ServiceManager");

            // get the desktop service
            var xDesktop = (XComponentLoader)xRemoteServiceManager.createInstance("com.sun.star.frame.Desktop");

            // load the pptx file
            var xComponent = xDesktop.loadComponentFromURL($"file:///{Path.GetFullPath(inputFile)}", "_blank", 0, new PropertyValue[0]);

            // export the pptx to pdf
            var xStorable = (XStorable)xComponent;
            var xExportFilter = (XFilter)xRemoteServiceManager.createInstance("com.sun.star.drawing.PDF");
            var xExportProperties = new PropertyValue[]
            {
                new PropertyValue { Name = "ReduceImageResolution", Value = new Any(true) },
                new PropertyValue { Name = "MaxImageResolution", Value = new Any(150) }
            };
            xStorable.storeToURL($"file:///{Path.GetFullPath(outputFile)}", xExportProperties);

            // close the pptx file
            var xCloseable = (XCloseable)xComponent;
            xCloseable.close(false);

            Console.WriteLine("Done!");
        }
    }
}

在这个示例中，我们使用 com.sun.star.frame.Desktop 服务加载 pptx 文件，然后使用 com.sun.star.drawing.PDF 过滤器将其导出为 pdf 文件。在导出过程中，我们设置了一些导出选项，例如将图像分辨率降低以减小文件大小。最后，我们使用 XCloseable 接口关闭打开的 pptx 文件。

请注意，此示例假设已经在本机上安装了 LibreOffice 并且正在运行。如果未安装 LibreOffice，您需要先安装它，并将 com.sun.star.connection.Connector 的参数中的 port 更改为适当的值