c# - 来自 WebAPI 的服务器调用图像

Question

我有一个为 DMZ(互联网)服务器提供服务的 Intranet WebAPI 服务器。

API 操作:

[HttpGet]
public HttpResponseMessage ImagePath(string filePath)
{
    var result = new HttpResponseMessage(HttpStatusCode.OK);
    FileStream fileStream = new FileStream(filePath, FileMode.Open);
    Image image = Image.FromStream(fileStream);
    MemoryStream memoryStream = new MemoryStream();
    image.Save(memoryStream, ImageFormat.Jpeg);
    result.Content = new ByteArrayContent(memoryStream.ToArray());
    result.Content.Headers.ContentType = new MediaTypeHeaderValue("image/jpeg");

    return result;
}

该 api 确实成功返回了图像。 我想继续从 DMZ 到 Intranet 的请求，但我不知道如何编写操作，我的代码如下:

public async Task<HttpResponseMessage> ImagePath(string filePath)
{ 
    HttpClientHandler handler = new HttpClientHandler()
    {
        UseDefaultCredentials = true,
    };

    using (var client = new HttpClient(handler)) {

        client.BaseAddress = new Uri(apiUrl); //apiUrl is my intranet domain
        client.DefaultRequestHeaders.Accept.Clear();
        client.DefaultRequestHeaders.Accept.Add(new System.Net.Http.Headers.MediaTypeWithQualityHeaderValue("image/jpeg"));

        HttpResponseMessage fs = await client.GetAsync("cipap/api/baseapi/ImagePath?filePath=" + filePath);
        return fs;

    }

    //FileStream fs = new FileStream(filePath, FileMode.Open);
    //return File(fs, "image/jpeg");
}

有人能帮帮我吗？非常感谢。

Answer 1

终于找到答案了，
只需执行 FileResult 类型的操作， 并通过以下方式返回文件:

File(fs.Content.ReadAsByteArrayAsync().Result, "image/jpeg");   

还有一件事是在 webapi 操作中，我需要如下配置文件流，否则文件将在第一次请求后被锁定:

FileStream fileStream = new FileStream(filePath, FileMode.Open, FileAccess.Read, FileShare.Read);

---

public async Task<FileResult> ImagePath(string filePath)
{

    HttpClientHandler handler = new HttpClientHandler()
    {
        UseDefaultCredentials = true,
    };

    using (var client = new HttpClient(handler)) {

        client.BaseAddress = new Uri(apiUrl);
        client.DefaultRequestHeaders.Accept.Clear();
        client.DefaultRequestHeaders.Accept.Add(new System.Net.Http.Headers.MediaTypeWithQualityHeaderValue("image/jpeg"));
        HttpResponseMessage fs = await client.GetAsync("cipap/api/baseapi/ImagePath?filePath=" + filePath);

        return File(fs.Content.ReadAsByteArrayAsync().Result, "image/jpeg");               
    }

}

引用: Download file prompt when using WebAPI HttpResponseMessage