/// <summary>
/// 将某个 <see cref="ViewModelBase"/> 中创建的 <see cref="AsyncCommandBase"/> 加入到异步互斥命令集合中进行统一管理。
/// </summary>
/// <param name="viewModel">异步互斥命令的互斥边界，在此 ViewModel 中。</param>
/// <param name="asyncCommand">互斥的异步命令。</param>
private static void ManageExclusiveCommand(
[NotNull] ViewModelBase viewModel, [NotNull] AsyncCommandBase asyncCommand)
{
if (!ManagedAsyncCommandDictionary.TryGetValue(viewModel, out var commands))
{
commands = new HashSet <AsyncCommandBase>();
ManagedAsyncCommandDictionary[viewModel] = commands;
}
commands.Add(asyncCommand);
}
/// <summary>
/// 找到与指定 <see cref="AsyncCommandBase"/> 异步命令互斥的所有异步命令。
/// </summary>
/// <param name="asyncCommand">查找与之互斥的异步命令。</param>
/// <returns>与指定异步命令互斥的所有异步命令。</returns>
internal static IEnumerable <AsyncCommandBase> FindExclusiveCommandsFrom([NotNull] AsyncCommandBase asyncCommand)
{
if (asyncCommand == null)
{
throw new ArgumentNullException(nameof(asyncCommand));
}
foreach (var pair in ManagedAsyncCommandDictionary)
{
if (pair.Value.Contains(asyncCommand))
{
return(FindExclusiveCommandsFrom(pair.Key));
}
}
return(Enumerable.Empty <AsyncCommandBase>());
}
