如何从asp.net web api 2返回文件(PDF)

public HttpResponseMessage GetPdfFile()
{
    // 读取PDF文件的内容
    byte[] fileBytes = System.IO.File.ReadAllBytes("path_to_pdf_file.pdf");

    // 创建HttpResponseMessage对象
    HttpResponseMessage response = new HttpResponseMessage(HttpStatusCode.OK);

    // 设置响应内容为PDF文件的内容
    response.Content = new ByteArrayContent(fileBytes);

    // 设置响应内容的MIME类型为application/pdf
    response.Content.Headers.ContentType = new MediaTypeHeaderValue("application/pdf");

    // 返回HttpResponseMessage对象
    return response;
}

using (HttpClient client = new HttpClient())
{
    HttpResponseMessage response = await client.GetAsync("api/controllername/getpdffile");

    if (response.IsSuccessStatusCode)
    {
        byte[] fileBytes = await response.Content.ReadAsByteArrayAsync();

        // 将文件保存到本地
        System.IO.File.WriteAllBytes("path_to_save_pdf_file.pdf", fileBytes);
    }
}