c# - 在 C# 中将参数传递给 Func<> 的最佳方法是什么？

Question

我有以下代码:

public void Test(Request request, Func<IEnumerable<Building>> buildings)
{
   vm.Buildings = Helper.GenerateDropdownList(request.BuildingId,() => buildings());
}

我现在想将一个额外的参数传递给 buildings() 回调

public void Test(Request request, Func<IEnumerable<Building>> buildings)
{
   var cityId = GetCity();
   vm.Buildings = Helper.GenerateDropdownList(request.BuildingId,() => buildings(cityId));
}

输入该参数的正确方法是什么？

Answer 1

你的 buildings代表需要是 Func<T, TResult> 而不是 Func<TResult> .

假设cityId是一个 int :

public void Test(Request request, Func<int, IEnumerable<Building>> buildings)
{
   var cityId = GetCity();
   m.Buildings = Helper.GenerateDropdownList(request.BuildingId,
                                             () => buildings(cityId));
}