HttpClient从URL下载图片然后上传图片

Question

I have an image that sits in a url.

https://somecdn/content/myimage.png

I want to pass this string to my API,Download the image into memory then upload to another API.

I'm using an api client that is generated from our swagger that takes a type of IO.stream.

Code is as follows.

    public async Task<int> UploadPicture(string fileUrl)
    {
        
        var otherApiClient = await _otherApiClient.Build();
        var fileRetrievalClient = new HttpClient();           

        var fileResponse = await fileRetrievalClient.GetAsync(fileUrl);
        

        var newId = await otherApiClient.UploadPictureAsync(file: await fileResponse.Content.ReadAsStreamAsync());

        return newId;
    }

Normally when this is called via the front end the types are set correctly correctly.

Content-Disposition: form-data; name="file"; filename="yadayada.png" Content-Type: image/png

However in my code the Content-Type is wrong.

Content-Type: application/octet-stream Content-Disposition: form-data; name=file; filename= unknown

How can I correct this.

Answer 1

you can do something like this:

var fileResponse = await fileRetrievalClient.GetAsync(fileUrl);
byte[] bytes = await fileResponse.Content.ReadAsByteArrayAsync();
using (var content = new ByteArrayContent(bytes))
{
    content.Headers.ContentType = new MediaTypeHeaderValue("application/octet-stream");
    content.Headers.TryAddWithoutValidation("Content-Disposition", "application/octet-stream name=test");
    var postResponse = await otherApiClient.PostAsync(uri, content);
}

Answer 2

HttpClient doesn't have a method called UploadPictureAsync . This indicates that the Type of variable otherApiClient is not HttpClient .

You need to check what other parameters you can pass to UploadPictureAsync and see how you can pass custom headers using the values from fileResponse.Headers