1、安装引用Aspose.Html

1）使用Nuget界面管理器

直接分别搜索 "Aspose.Html"，找到对应的点安装即可。

相关文档：VS(Visual Studio)中Nuget的使用

2）使用Package Manager命令安装

PM> Install-Package Aspose.Html

注意：使用Aspose是需要有License的，如没有也可以网上找一下破解版本。

2、使用Aspose.Html将HTML转成PDF

使用Aspose.HTML for .NET 提供了Converter类的静态方法，可以很方便的将HTML转换成PDF，代码如下，

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Aspose.Html.Converters;
using Aspose.Html.Saving;

namespace ConsoleApplication
{
    class Program
    {
        public static string outputFile { get; private set; }


       static void Main(string[] args)
        {
            //var license = new Aspose.Html.License();
            //license.SetLicense("Aspose.Html.lic");
            Converter.ConvertHTML(@"<h1>Convert HTML to PDF!</h1>", ".", new PdfSaveOptions(), Path.Combine("/home/cjavapy", "convert-with-single-line.pdf"));
            Console.ReadKey();
        }
    }
}

3、使用Aspose.Html将URL中HTML转换PDF

使用Aspose.Html中HTMLDocument可以直接指定URL，将URL中HTML转换PDF，代码如下，

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Text;
using System.Threading.Tasks;
using Aspose.Html;
using Aspose.Html.Converters;
using Aspose.Html.Dom;
using Aspose.Html.Saving;

namespace ConsoleApplication
{
    class Program
    {

        private static Stream GetContentFromUrlAsStream(string url, ICredentials credentials = null)
        {
            using (var handler = new HttpClientHandler { Credentials = credentials })
            using (var httpClient = new HttpClient(handler))
            {
                return httpClient.GetStreamAsync(url).GetAwaiter().GetResult();
            }
        }
        static void Main(string[] args)
        {
            //var license = new Aspose.Html.License();
            //license.SetLicense("Aspose.Html.lic");
            const string url = "https://en.wikipedia.org/wiki/Aspose_API";
            var document = new HTMLDocument(url);
            Converter.ConvertHTML(document, new PdfSaveOptions(),"/home/cjavapy/output.pdf");
            Console.ReadKey();
        }
    }
}