/// <summary>
/// 跳转到指定的 <paramref name="viewModelPage" /> 添加消息
/// </summary>
/// <param name="sender"></param>
/// <param name="viewModelPage"></param>
/// <param name="parameter"></param>
public void Navigate(INavigateable sender, ViewModelPage viewModelPage, object parameter = null)
{
if (viewModelPage == null)
{
throw new ArgumentNullException(nameof(viewModelPage));
}
if (sender == null)
{
throw new ArgumentNullException(nameof(sender));
}
var receiveMessage = sender as IReceiveMessage;
var lastViewModel = _lastViewModelPage?.ViewModel?.GetViewModel();
if (lastViewModel is INavigable lastNavigableViewModel)
{
lastNavigableViewModel.NavigatedFrom(sender, parameter);
}
if (receiveMessage != null && lastViewModel is ISendMessage lastSendMessage)
{
lastSendMessage.Send -= receiveMessage.ReceiveMessage;
}
// 开始跳转
var viewModel = viewModelPage.ViewModel.GetViewModel();
if (viewModel == null)
{
throw new ArgumentException("无法从ViewModel.GetViewModel拿到ViewModel值");
}
if (receiveMessage != null)
{
if (viewModel is ISendMessage sendMessage)
{
sendMessage.Send -= receiveMessage.ReceiveMessage;
sendMessage.Send += receiveMessage.ReceiveMessage;
}
}
if (viewModel is INavigable navigable)
{
navigable.NavigatedTo(sender, parameter);
}
Frame.Navigate(viewModelPage.Page, viewModel);
_lastViewModelPage = viewModelPage;
}
/// <inheritdoc />
public override void ReceiveMessage(object sender, IMessage message)
{
ViewModelBase viewModel = this;
var composite = message as ICombinationComposite;
composite?.Run(viewModel, message);
var run = MVVM.Framework.ViewModel.Composite.Run(viewModel, message, Composite);
if (run)
{
return;
}
// 所有在这个 ViewModel 的 ViewModel 判断是否需要
// 解决 A B 两个通信
foreach (var temp in ViewModelPage.Where(/*如果 ViewModel 没有使用，就不收消息*/ temp => temp.ViewModel.IsLoaded)
.Select(temp => temp.ViewModel.GetViewModel()))
{
ViewModel.Composite.Run(temp, message, Composite);
}
}
