C# 下载网络地址PDF文件并打印 示例代码

在C#中下载网络地址的PDF文件并打印，你可以使用HttpClient来获取文件内容，然后利用PdfSharp库将PDF解析并打印。以下是简单的示例代码：

using System;
using System.IO;
using System.Net.Http;
using iTextSharp.text.pdf;
using iTextSharp.text.pdf.parser;

public class PdfDownloaderAndPrinter
{
    public static void DownloadAndPrintPdf(string url)
    {
        try
        {
            // 1. 使用HttpClient下载PDF文件
            using (var httpClient = new HttpClient())
            {
                var response = httpClient.GetAsync(url).Result;
                if (!response.IsSuccessStatusCode)
                    throw new Exception($"Failed to download PDF. Status code: {response.StatusCode}");

                byte[] pdfBytes = response.Content.ReadAsByteArrayAsync().Result;
            }

            // 2. 将字节数组转换为Stream
            using (MemoryStream memoryStream = new MemoryStream(pdfBytes))
            {
                // 3. 创建PdfDocument实例并读取PDF
                PdfDocument document = PdfReader.Open(memoryStream, null);

                // 4. 获取第一份页面
                var page = document.GetPage(1);
                // 打印PDF
                PrintDocument printDoc = new PrintDocument();
                PrintPreviewForm previewForm = new PrintPreviewForm(printDoc);
                printDoc.PrinterSettings.DefaultPageRange = "1";

                // 注册PrintPage事件处理程序
                printDoc.PrintPage += (_, e) =>
                {
                    // 将页面内容绘制到PrintDocument上
                    XImage img = Image.GetInstance(page);
                    e.Graphics.DrawImage(img, 0, 0);
                };

                // 显示预览
                previewForm.ShowDialog();

                // 关闭文档和内存流
                document.Close();
                memoryStream.Dispose();
            }
        }
        catch (Exception ex)
        {
            Console.WriteLine($"Error occurred: {ex.Message}");
        }
    }
}

// 调用函数
string pdfUrl = "https://example.com/file.pdf"; // 替换为你需要下载的PDF链接
PdfDownloaderAndPrinter.DownloadAndPrintPdf(pdfUrl);