C#导出pdf的实现方法（浏览器不预览直接下载）

技术  /  管理员 发布于 5年前   253

前言

这篇文章主要给大家介绍了关于C#导出pdf的实现方法，分享出来供大家参考学习，下面话不多说了，来一起看看详细的介绍吧

方法如下：

一.接口部分的代码

[HttpGet]    public HttpResponseMessage ExportPdf(string id)    {      string pdfName = "";　　　　　　　//id 查询条件，根据实际情况修改即可　　　　　　　//pdfName 例如download.pdf      byte[] pdfData= _policyGapManagerService.ExportPdf(id, out pdfName);//获得pdf字节      var result = new HttpResponseMessage(HttpStatusCode.OK)      {        Content = new ByteArrayContent(pdfData)      };      result.Content.Headers.ContentDisposition =        new ContentDispositionHeaderValue("attachment")        {          FileName = pdfName        };      result.Content.Headers.ContentType =new MediaTypeHeaderValue("application/pdf");      return result;    }

二.返回pdfbyte数组

1.下载http模式的pdf文件（以ASP.NET为例，将PDF存在项目的目录下，可以通过http直接打开项目下的pdf文件）

#region 调用本地文件使用返回pdfbyte数组    /// <summary>    /// 调用本地文件使用返回pdfbyte数组    /// </summary>    /// <param name="srcPdfFile">‘D:\in2434341555551.pdf'</param>    /// <returns></returns>    public static byte[] GetSignaturePDFByte(string srcPdfFile)    {      using (FileStream fsRead = new FileStream(srcPdfFile, FileMode.Open, FileAccess.Read, FileShare.Read))      {        int fsLen = (int)fsRead.Length;        byte[] hebyte = new byte[fsLen];        fsRead.Read(hebyte, 0, hebyte.Length);        return hebyte;      }    }    #endregion 调用本地文件使用返回pdfbyte数组    #region 从网站上下载pdf，转化为字节流    /// <summary>    /// 从网站上下载pdf，转化为字节流    /// </summary>    /// <param name="srcPdfFile">文件地址：'https://******/group2/M00/00/04/wKj-mlpcoZ2IUbK5AACrpaV6k98AAAB6gAAAAAAAKu9562.pdf'</param>    /// <returns></returns>    public static Byte[] GetByteByRemoteURL(string srcPdfFile)    {      byte[] arraryByte;      HttpWebRequest req = (HttpWebRequest)HttpWebRequest.Create(srcPdfFile);      req.Method = "GET";      using (WebResponse wr = req.GetResponse())      {        StreamReader responseStream = new StreamReader(wr.GetResponseStream(), Encoding.UTF8);        int length = (int)wr.ContentLength;        byte[] bs = new byte[length];        HttpWebResponse response = wr as HttpWebResponse;        Stream stream = response.GetResponseStream();        //读取到内存        MemoryStream stmMemory = new MemoryStream();        byte[] buffer1 = new byte[length];        int i;        //将字节逐个放入到Byte 中        while ((i = stream.Read(buffer1, 0, buffer1.Length)) > 0)        {          stmMemory.Write(buffer1, 0, i);        }        arraryByte = stmMemory.ToArray();        stmMemory.Close();      }      return arraryByte;    }    #endregion 从网站上下载pdf，转化为字节流    #region 从网站上下载文件，保存到其他路径    /// <summary>    /// 从网站上下载文件，保存到其他路径    /// </summary>    /// <param name="pdfFile">文件地址</param>    /// <param name="saveLoadFile">保存文件路径：D:\12221.pdf</param>    /// <returns></returns>    public string SaveRemoteFile( string saveLoadFile , string pdfFile)    {      //bool flag = false;      var f = saveLoadFile + Guid.NewGuid().ToString("D") + ".pdf";      Uri downUri = new Uri(pdfFile);      //建立一个ＷＥＢ请求，返回HttpWebRequest对象      HttpWebRequest hwr = (HttpWebRequest)WebRequest.Create(downUri);      //流对象使用完后自动关闭      using (Stream stream = hwr.GetResponse().GetResponseStream())      {        //文件流，流信息读到文件流中，读完关闭        using (FileStream fs = File.Create(f))        {          //建立字节组，并设置它的大小是多少字节          byte[] bytes = new byte[102400];          int n = 1;          while (n > 0)          {//一次从流中读多少字节，并把值赋给Ｎ，当读完后，Ｎ为０,并退出循环n = stream.Read(bytes, 0, 10240);fs.Write(bytes, 0, n);　//将指定字节的流信息写入文件流中          }        }      }      //return flag;      //return _outPath + saveLoadFile;      return f;    }    #endregion 从网站上下载文件，保存到其他路径

2.ftp模式的pdf文件

/// <summary>    /// 下载FTP文件。    /// </summary>    /// <param name="offsetPath">相对路径</param>    /// <param name="fileName">文件名称</param>    /// <returns>下载结果，本地文件路径</returns>    public string DownLoad(string offsetPath,string fileName)    {      try      {        FtpWebRequest ftpWeb = (FtpWebRequest)WebRequest.Create(_ftpRootPath + offsetPath + fileName);        ftpWeb.Method = WebRequestMethods.Ftp.DownloadFile;        ftpWeb.UseBinary = true;        var resp = ftpWeb.GetResponse();        using (FileStream fs = new FileStream(_outPath + fileName, FileMode.Create))        {          using (var s = resp.GetResponseStream())          {if (s == null) { return "文件不存在!"; }int readCout = 0;byte[] bytes = new byte[1024];readCout = s.Read(bytes, 0, 1024);while (readCout > 0){  fs.Write(bytes, 0, readCout);  readCout = s.Read(bytes, 0, 1024);}          }        }        resp.Close();        return _outPath + fileName;      }      catch (Exception e)      {        return e.Message;      }          }    /// <summary>    /// 判断文件是否存在    /// </summary>    /// <param name="offsetPath"></param>    /// <param name="fileName"></param>    /// <returns></returns>    public bool FileExists(string offsetPath, string fileName)    {      try      {        FtpWebRequest ftpWeb = (FtpWebRequest)WebRequest.Create(_ftpRootPath + offsetPath + fileName);        ftpWeb.Method = WebRequestMethods.Ftp.DownloadFile;        ftpWeb.UseBinary = true;        var resp = (FtpWebResponse)ftpWeb.GetResponse();        resp.Close();        return true;      }      catch (Exception)      {        return false;      }    }    /// <summary>    /// 获取目录下所有文件    /// </summary>    /// <returns></returns>    public string[] Files(string offsetPath)    {      try      {        FtpWebRequest ftpWeb = (FtpWebRequest)WebRequest.Create(_ftpRootPath + offsetPath);        ftpWeb.Method = WebRequestMethods.Ftp.ListDirectory;        Stream stream = ftpWeb.GetResponse().GetResponseStream();        if (stream == null)        {          return null;        }        List<string> fileList = new List<string>();        using (StreamReader sr = new StreamReader(stream))        {          StringBuilder sb = new StringBuilder();          do          {sb.Append(sr.ReadLine());if (sb.Length > 0){  fileList.Add(sb.ToString());  sb.Clear();}else{  break;}          } while (true);        }        return fileList.ToArray();      }      catch (Exception)      {         return null;      }    }

总结

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