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我必须从磁盘或网络链接中检索图像,调整其大小并将其流式传输到客户端应用程序。这是我的控制器方法。如何在asp.net web api中将图像流式传输到客户端应用程序?
[HttpPost]
[ActionName("GetImage")]
public HttpResponseMessage RetrieveImage(ImageDetails details)
{
if (!details.Filename.StartsWith("http"))
{
if (!FileProvider.Exists(details.Filename))
{
throw new HttpResponseException(Request.CreateResponse(HttpStatusCode.NotFound, "File not found"));
}
var filePath = FileProvider.GetFilePath(details.Filename);
details.Filename = filePath;
}
var image = ImageResizer.RetrieveResizedImage(details);
MemoryStream stream = new MemoryStream();
// Save image to stream.
image.Save(stream, System.Drawing.Imaging.ImageFormat.Jpeg);
var response = new HttpResponseMessage();
response.Content = new StreamContent(stream);
response.Content.Headers.ContentDisposition
= new ContentDispositionHeaderValue("attachment");
response.Content.Headers.ContentDisposition.FileName = details.Filename;
response.Content.Headers.ContentType
= new MediaTypeHeaderValue("application/octet-stream");
return response;
}
这是怎么了发送的网页链接(在这种情况下),并在客户端应用程序结束接收图像。
HttpClient client = new HttpClient();
client.BaseAddress = new Uri("http://localhost:27066");
client.DefaultRequestHeaders.Accept.Add(
new MediaTypeWithQualityHeaderValue("application/octet-stream"));
ImageDetails img = new ImageDetails { Filename = "http://2.bp.blogspot.com/-W6kMpFQ5pKU/TiUwJJc8iSI/AAAAAAAAAJ8/c3sJ7hL8SOw/s1600/2011-audi-q7-review-3.jpg", Height = 300, Width = 200 };
var response = await client.PostAsJsonAsync("api/Media/GetImage", img);
response.EnsureSuccessStatusCode(); // Throw on error code.
var stream = await response.Content.ReadAsStreamAsync();
FileStream fileStream = System.IO.File.Create("ImageName");
// Initialize the bytes array with the stream length and then fill it with data
byte[] bytesInStream = new byte[stream.Length];
stream.Read(bytesInStream, 0, (int)bytesInStream.Length);
// Use write method to write to the specified file
fileStream.Write(bytesInStream, 0, (int) bytesInStream.Length);
MessageBox.Show("Uploaded");
的图像从网页链接检索和调整大小得当,但如果它被proeprly流作为它的创造与当客户端应用程序收到“ImageName”一个0KB文件我不知道。任何人都可以告诉我哪里错了?我一直在敲打我的脑袋一下一整天:(
客户端流stream.Length的值是什么 –
零:(这就是为什么我认为流处理没有正确完成,但是当我把一个断点放在“image.Save “在控制器方法中,流显示相当长的时间,这意味着图像正被保存到流中。问题可能在于流没有正确地连接到HttpContent或其他东西。有什么建议么? – Bitsian
你在小提琴手中看到了什么?服务器是否向响应流发送了一些内容? –