public void Add(DownloadListBoxItem item)
{
CheckIfNotContains(item, item.DownloadButton, item.CancelButton, item.RemoveButton);
downloadToItems.Add(item.DownloadButton, item);
cancelToItems.Add(item.CancelButton, item);
removeToItems.Add(item.RemoveButton, item);
}
private void CheckIfNotContains(DownloadListBoxItem item, Button downloadButton, Button cancelButton, Button removeButton)
{
if (downloadToItems == null || cancelToItems == null || removeToItems == null)
{
throw new NullReferenceException("Dictionary cannot be null");
}
if (item == null || downloadButton == null || cancelButton == null || removeButton == null)
{
throw new ArgumentNullException("Argument cannot be null");
}
if (downloadToItems.ContainsKey(downloadButton) ||
cancelToItems.ContainsKey(cancelButton) ||
removeToItems.ContainsKey(removeButton))
{
throw new ArgumentException("An element with the same key already exists in the dictionary");
}
if (downloadToItems.ContainsValue(item) ||
cancelToItems.ContainsValue(item) ||
removeToItems.ContainsValue(item))
{
throw new ArgumentException("An element with the same value already exists in the dictionary");
}
}