下载和显示PDF文件，一个非常相似的代码剪辑如下:

  private downloadFile(data: Response): void {
    let blob = new Blob([data.blob()], { type: "application/pdf" });
    let url = window.URL.createObjectURL(blob);
    window.open(url);
  }

  public showFile(fileEndpointPath: string): void {
    let reqOpt: RequestOptions = this.getAcmOptions();  //  getAcmOptions is our helper method. Change this line according to request headers you need.
    reqOpt.responseType = ResponseContentType.Blob;
    this.http
      .get(fileEndpointPath, reqOpt)
      .subscribe(
        data => this.downloadFile(data),
        error => alert("Error downloading file!"),
        () => console.log("OK!")
      );
  }

这个怎么样?

this.http.get(targetUrl,{responseType:ResponseContentType.Blob})
        .catch((err)=>{return [do yourself]})
        .subscribe((res:Response)=>{
          var a = document.createElement("a");
          a.href = URL.createObjectURL(res.blob());
          a.download = fileName;
          // start download
          a.click();
        })

我可以接受。 不需要额外包装。

如果您尝试在订阅内部调用新方法，效果会更好

this._reportService.getReport()
    .subscribe((data: any) => {
        this.downloadFile(data);
    },
        (error: any) => сonsole.log(error),
        () => console.log('Complete')
    );

在downloadFile(data)函数中，我们需要创建block, link, href和文件名

downloadFile(data: any, type: number, name: string) {
    const blob = new Blob([data], {type: 'text/csv'});
    const dataURL = window.URL.createObjectURL(blob);

    // IE doesn't allow using a blob object directly as link href
    // instead it is necessary to use msSaveOrOpenBlob
    if (window.navigator && window.navigator.msSaveOrOpenBlob) {
      window.navigator.msSaveOrOpenBlob(blob);
      return;
    }

    const link = document.createElement('a');
    link.href = dataURL;
    link.download = 'export file.csv';
    link.click();

    setTimeout(() => {

      // For Firefox it is necessary to delay revoking the ObjectURL
      window.URL.revokeObjectURL(dataURL);
      }, 100);
    }
}

对于较新的angular版本:

npm install file-saver --save
npm install @types/file-saver --save


import {saveAs} from 'file-saver';

this.http.get('endpoint/', {responseType: "blob", headers: {'Accept': 'application/pdf'}})
  .subscribe(blob => {
    saveAs(blob, 'download.pdf');
  });

虽然这个问题很老了，但没有一个答案是可行的。 据我所知，所有的文件都是先加载到内存中，然后保存。 这样我们:

导致延迟，为此必须实现自定义加载。 将文件加载到内存中，这意味着对于大文件，浏览器将崩溃。 请勿使用已实现的浏览器下载功能。

前端端非常简单(Angular 12):

downloadFile(url: string, fileName: string): void {
   const downloadLink = document.createElement('a');
   downloadLink.download = fileName;
   downloadLink.href = url;
   downloadLink.click();
}

在后端(。NET 6)我们需要使用流并写入响应体:

public void Get(string fileId)
{
    var fileName = fileService.GetFileName(fileId);
    var fileContentType = fileService.GetFileContentType(fileId);
    this.Response.Headers.Add(HeaderNames.ContentType, fileContentType);
    this.Response.Headers.Add(HeaderNames.ContentDisposition, $"attachment; filename=\"{fileName}\"");
    fileService.GetFile(Response.Body, fileId);
}

文件内容类型和名称可以从DB(如果您将文件信息保存在其中)或文件系统中检索。 从扩展解析内容类型。

我像这样写入流:

public void GetFile(Stream writeStream, string fileId)
{
    var file = GetFileInfo(fileId);
    try
    {
        var fileStream = File.OpenRead(file.FullName);
        byte[] buffer = new byte[32768];
        int read;
        while ((read = fileStream.Read(buffer, 0, buffer.Length)) > 0)
        {
            writeStream.Write(buffer, 0, read);
        }
        writeStream.Flush();
    }
    catch (Exception e)
    {
        throw new CustomException($"Error occured while reading the file. Inner Exception Message: ({e.Message}) Stack Trace: ({e.StackTrace})", ErrorCode.FileReadFailure, e);
    }
}

请记住，为了表示目的，我简化了我的实现，所以还没有对其进行测试。

到目前为止，我发现这些答案既缺乏洞察力，也缺乏警告。你可以也应该注意与IE10+的不兼容性(如果你在乎的话)。

这是完整的示例，其中包括应用程序部分和服务部分。注意，我们设置了observe: "response"来捕捉文件名的头信息。还要注意，Content-Disposition报头必须由服务器设置并公开，否则当前的Angular HttpClient将不会传递它。我在下面添加了一段dotnet核心代码。

public exportAsExcelFile(dataId: InputData) {
    return this.http.get(this.apiUrl + `event/export/${event.id}`, {
        responseType: "blob",
        observe: "response"
    }).pipe(
        tap(response => {
            this.downloadFile(response.body, this.parseFilename(response.headers.get('Content-Disposition')));
        })
    );
}

private downloadFile(data: Blob, filename: string) {
    const blob = new Blob([data], {type: 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet;charset=utf-8;'});
    if (navigator.msSaveBlob) { // IE 10+
        navigator.msSaveBlob(blob, filename);
    } else {
        const link = document.createElement('a');
        if (link.download !== undefined) {
            // Browsers that support HTML5 download attribute
            const url = URL.createObjectURL(blob);
            link.setAttribute('href', url);
            link.setAttribute('download', filename);
            link.style.visibility = 'hidden';
            document.body.appendChild(link);
            link.click();
            document.body.removeChild(link);
        }
    }
}

private parseFilename(contentDisposition): string {
    if (!contentDisposition) return null;
    let matches = /filename="(.*?)"/g.exec(contentDisposition);

    return matches && matches.length > 1 ? matches[1] : null;
}

Dotnet核心，具有内容处理和媒体类型

 private object ConvertFileResponse(ExcelOutputDto excelOutput)
    {
        if (excelOutput != null)
        {
            ContentDisposition contentDisposition = new ContentDisposition
            {
                FileName = excelOutput.FileName.Contains(_excelExportService.XlsxExtension) ? excelOutput.FileName : "TeamsiteExport.xlsx",
                Inline = false
            };
            Response.Headers.Add("Access-Control-Expose-Headers", "Content-Disposition");
            Response.Headers.Add("Content-Disposition", contentDisposition.ToString());
            return File(excelOutput.ExcelSheet, "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
        }
        else
        {
            throw new UserFriendlyException("The excel output was empty due to no events.");
        }
    }