/// <summary>
/// Create Attachment data object using the give parameters.
/// </summary>
/// <param name="name">Attachment name.</param>
/// <param name="content">Attachment content url.</param>
/// <param name="contentType">Attachment content type.</param>
/// <returns>A valid AttachmentData instance.</returns>
private async Task <AttachmentData> CreateAttachmentDataAsync(string name, string content, string contentType)
{
if (string.IsNullOrEmpty(contentType))
{
throw new ArgumentNullException(nameof(contentType), "Content type can not be null.");
}
if (string.IsNullOrEmpty(content))
{
throw new ArgumentNullException(nameof(content), "Content url can not be null.");
}
// ContentUrl can contain a url or dataUrl of the form "data:image/jpeg;base64,XXXXXXXXX..."
byte[] bytesData;
if (AttachmentHelper.IsUrl(content))
{
bytesData = await _wechatClient.SendHttpRequestAsync(HttpMethod.Get, content, timeout : 60000).ConfigureAwait(false);
}
else
{
bytesData = AttachmentHelper.DecodeBase64String(content, out contentType);
}
name = name ?? Guid.NewGuid().ToString();
// should be lower by WeChat.
#pragma warning disable CA1308
contentType = contentType.ToLowerInvariant();
#pragma warning restore CA1308
return(new AttachmentData(contentType, name, bytesData, bytesData));
}