如何 post 图像正确地 URL ？

Question

我正在尝试 post 将图像发送到 StockTwits API，但收到 422 错误作为响应，表示无法识别图像格式。该图像是 png 文件，因此它应该是有效的文件格式。我试过使用具有相同响应的 jpeg。

我是否对图像编码不正确，或者 HttpClient 中缺少某些配置？

public void Share(string text, string imageFilePath)
{
    using(HttpClient client = new HttpClient())
        using (MultipartFormDataContent formData = new MultipartFormDataContent())
        {
            string      url             = stocktwitsCreateMessageUrl + "&" +
                                            "body="         + Core.Globals.UrlEncode(twit)  + "&" +
                                            "sentiment="    + StockTwitsSentiment.ToString().ToLower();

            byte[]      imageBytes      = File.ReadAllBytes(imageFilePath);
            HttpContent imageContent    = new ByteArrayContent(imageBytes);
            string      fileName        = Path.GetFileName(imageFilePath);
            formData.Add(imageContent, "chart", fileName); 
            HttpResponseMessage stockTwitsResponse  = await client.PostAsync(url, formData);
            Stream              responseContent     = await stockTwitsResponse.Content.ReadAsStreamAsync();
            string              result              = new StreamReader(responseContent).ReadToEnd();
            Print(result); // helper method
            if (!stockTwitsResponse.IsSuccessStatusCode)
            {
                LogErrorResponse(result, stockTwitsResponse);
                return;
            }
            else
                LogAndPrint(typeof(Custom.Resource), "ShareStockTwitsSentSuccessfully", new[] { Name }, Cbi.LogLevel.Information);
        }
}

回复：

{

"response": { "status": 422 },

"errors": [ { "message": "We couldn't recognize the image format. Format must be one of: image/jpg image/jpeg image/pjpeg image/png image/x-png image/gif" } ]

}

Answer 1

别忘了将 Content-Type header 设置为 "image/png"！

参见：https://msdn.microsoft.com/en-us/library/system.net.httpwebrequest.contenttype(v=vs.110).aspx

如何 post 图像正确地 URL ？

How to post image to URL properly?

c#

http

stocktwits