Question

I cannot load image from Zend server with following code:

Console.WriteLine(">" + url);
Console.WriteLine(">" + NSUrl.FromString(url));
Console.WriteLine(">" + NSData.FromUrl(NSUrl.FromString(url))); // Null on this line

It appears only when I’m trying to load image from my server, any other source works fine. Here is my Zend controller code:

public function getAction()
{
    $file_id = (int)$this->_getParam('id');
    $file = $this->fileModel->getById($file_id);

    $this->getResponse()
        ->setHttpResponseCode(200)
        ->setHeader('Pragma', 'public', true)
        ->setHeader('Expires', '', true)
        ->setHeader('Cache-Control', 'public', true)
        ->setHeader('Cache-Control', 'max-age=3800')
        ->setHeader('Content-type', $file->CONTENT_TYPE, true)
        ->setHeader('Content-Length', $file->FILE_SIZE)
        ->clearBody();
    $this->getResponse()->sendHeaders();

    echo base64_decode($file->FILEBODY);
    exit;
}

Image showed fine in browser. What’s wrong with my code?

PS: my server works throught HTTPS without any signed certificate

Answer 1

NSData.FromUrl (dataWithContentsOfURL: in Objective-C) will return null for any error.

From Apple documentation:

Returns nil if the data object could not be created.

So something went wrong…

PS: my server works throught HTTPS without any signed certificate

Doubtful. You likely have a self-signed certificate (or your server should not be happy). Anyway…

If, when trying your URL, Safari (from your iPhone/iPad) warns you about your site then it falls into the something went wrong category and the null value you get is normal.

You might want to try HTTP: to make sure it’s not related to something else (e.g. networking issues).

Now if you *really want to use an untrusted SSL server you can use some .NET API, e.g. WebClient.

 var wc = new WebClient ();
 byte[] data = wc.DownloadData (url);

That alone will get you an exception (untrusted SSL server) but IMO that’s already better than simply a null.

Next you’ll need to vouch for the untrusted certificate. There’s a few different ways to do it (some much better than others). I fairly complete list of them (with source) code can be found in this article.