private void NavigateContent(string tag)
{
if (!ContentMap.ContainsKey(tag))
{
Debug.WriteLine($"未知的内容: {tag}");
return;
}
if (NavigateHistory.ContainsKey(tag))
{
// has history
if (previousTag != null)
{
// save previous content history
NavigateHistory[previousTag] = ContentFrame.GetNavigationState();
}
// restore history
ContentFrame.SetNavigationState(NavigateHistory[tag]);
}
else
{
// navigate to new content
ContentFrame.Navigate(ContentMap[tag]);
}
previousTag = tag;
}
