为什么我的int类型属性设置为null?

Hopefully I've just done something dumb but I get an int array and I want to assign that to a property - but even though the int array is not null, when I assign it to the property it is null. Note this is broken into several statements as I was testing that my select statement worked ok.

希望我做了一些蠢事，但我得到了一个int数组，我想把它赋值给一个属性——但即使int数组不是null，当我赋值给这个属性时，它也是空的。注意，在我测试select语句是否正常时，这被分成了几个语句。

int[] placementslist = selfSelPlacements.Select(p => p == null ? 0 : p.PlacementId).ToArray<int>();

I have tried

我有试过

UnitOfferingListCriteria.Placements = new int[placementslist.Length];

as well as just assigning

除了分配

UnitOfferingListCriteria.Placements = placementslist;

But UnitOfferingListCriteria.Placements is always null despite placementslist having 1 item.

但UnitOfferingListCriteria。尽管placement.com有一个条目，但它始终是空的。

In my class for the property

在我的课上

public int[] Placements { get; set; }

If someone could point out what I'm doing wrong - thanks!

如果有人能指出我做错了什么-谢谢!

Edit - thanks for the suggestions, been swamped with other stuff so haven't had a chance to get back to it yet.

编辑-谢谢你的建议，被其他的东西淹没了，所以还没有机会回到它。

3 个解决方案

#1

public int[] Placements { get; set; }

will have a default value of null.

默认值为null。

Is UnitOfferingListCriteria a class or a class instance? It looks like you are doing something with a static property? Or are you accessing a property on a property?

UnitOfferingListCriteria是类还是类实例?看起来你在用静态属性做什么?或者你正在访问一个属性上的属性?

#2

This works for me

这适合我

int[] placementslist = selfSelPlacements.Select(p => p == null ? 0 : p.PlacementId).ToArray<int>();
UnitOfferingListCriteria.Placements = new int[placementslist.Length];
placementslist.CopyTo(UnitOfferingListCriteria.Placements, 0);

And the class

和类

public class UnitOfferingListCriteria
{
    public static int[] Placements{ get; set; }
}

Are you doing anything different?

你有什么不同吗?

#3

The instance you are trying to reference in the property must not be null when you do it. This is obvious, but sometimes obvious is just much obvious.

您试图在属性中引用的实例在执行时一定不能为空。这是显而易见的，但有时显然是显而易见的。

#1

public int[] Placements { get; set; }