public static Task InvokeAsync(DeviceFeature deviceFeature, DeviceFeatureInvocationContext ctx, ActionCommand actionCommand)
{
var actionCommandType = actionCommand.GetType();
var invoker = _invokerCache.GetOrAdd(actionCommandType, _ =>
{
var actionCommandSupportType = typeof(IActionCommandSupport <>).MakeGenericType(actionCommandType);
var method = actionCommandSupportType.GetMethod("InvokeAsync");
var thisArg = Expression.Parameter(typeof(object));
var arg0 = Expression.Parameter(typeof(DeviceFeatureInvocationContext));
var arg1 = Expression.Parameter(typeof(ActionCommand));
// (thisArg, arg0, arg1) => (thisArg is IActionCommandSupport<T>)
// ? ((IActionCommandSupport<T>)thisArg).InvokeAsync(arg0, (<ActionCommand>)arg1)
// : Task.CompletedTask;
var call = Expression.Condition(Expression.TypeIs(thisArg, actionCommandSupportType),
Expression.Call(Expression.Convert(thisArg, actionCommandSupportType), method, arg0, Expression.Convert(arg1, actionCommandType)),
Expression.Property(null, typeof(Task).GetProperty("CompletedTask")));
var lambda = Expression.Lambda(call, thisArg, arg0, arg1);
return((Func <object, DeviceFeatureInvocationContext, ActionCommand, Task>)lambda.Compile());
});
return(invoker(deviceFeature.Instance, ctx, actionCommand));
}
public Task InvokeAsync(ActionCommand actionCommand)
{
if (actionCommand == null)
{
return(Task.CompletedTask);
}
if (ActionCommand.ByType.TryGetValue(actionCommand.GetType(), out var command))
{
if (FeatureByCommand.TryGetValue(command, out var feature))
{
var ctx = new DeviceFeatureInvocationContext(this);
return(feature.InvokeAsync(ctx, actionCommand));
}
}
return(Task.CompletedTask);
}