c# - Lambda 表达式和 InvokeOperation

Question

我有这段代码，但不知道如何通过 Lambda 表达式简化它？

public void LoadEntities(QueryBuilder<Device> query, Action<ServiceLoadResult<Device>> callback, object state)
{
    InvokeOperation<List<DivisionHierarchy>> obj = this.Context.GetAllDivisions();

    obj.Completed += new EventHandler(obj_Completed);   
}

void obj_Completed(object sender, EventArgs e)
{
    try
    {
        if (sender is InvokeOperation<List<DivisionHierarchy>>)
        {
            ObservableCollection<DivisionHierarchy> divisions = 
                new ObservableCollection<DivisionHierarchy>((sender as InvokeOperation<List<DivisionHierarchy>>).Value);
        }
    }
    catch  
    {                 
    }
} 

Answer 1

你的问题有点太宽泛，所以我在这里猜测，但 lambda 表达式的唯一地方是 Hook 到事件中。因此，您可以这样做，而不是使用单独的 obj_Completed 方法:

    public void LoadEntities(QueryBuilder<Device> query, Action<ServiceLoadResult<Device>> callback, object state)
    {
        InvokeOperation<List<DivisionHierarchy>> obj = this.Context.GetAllDivisions();

        obj.Completed += (sender, e) =>
        {
           try
           {
               if (sender is InvokeOperation<List<DivisionHierarchy>>)
               {
                   ObservableCollection<DivisionHierarchy> divisions = 
                       new ObservableCollection<DivisionHierarchy>((sender as InvokeOperation<List<DivisionHierarchy>>).Value);

               }
           }
           catch  
           {                 
           }
       } 
     }