c# - c#中的托管指针数组

Question

我在创建托管指针数组时遇到了问题。

我试过了

public unsafe class Car
{
    public int speed;

    public Car()
    {
        speed = 0;
    }

    public Car(int speed)
    {
        this.speed = speed;
    }
}

class Program
{
    public static unsafe void Main(string[] args)
    {
        var arr = new Car[10]; // 1st way
        fixed(Car* ptr = arr)
        {}

        Car* arr = stackalloc Car[10]; // 2nd way
    }
}

两次尝试后，我得到相同的错误:“无法获取地址或大小或定义托管类型的指针”。有人知道如何解决吗？

Answer 1

嗯，作为C# specs说:

Unlike references (values of reference types), pointers are nottracked by the garbage collector—the garbage collector has noknowledge of pointers and the data to which they point.

For thisreason a pointer is not permitted to point to a reference or to astruct that contains references, and the referent type of a pointermust be an unmanaged-type. An unmanaged-type is any type that isn’t areference-type and doesn’t contain reference-type fields at any levelof nesting. In other words, an unmanaged-type is one of the following:

sbyte, byte, short, ushort, int, uint, long, ulong, char, float,double, decimal, or bool.

Any enum-type.

Any pointer-type. Any user-defined struct-type that contains fields of unmanaged-types only.