C#System.Runtime.InteropServices.Marshal.PtrToStructure不断出现“；System.ExecutionEngineeException”；错误消息

我做错了什么？

不清楚在StructureToPtr或PtrToStructure上哪里会出现错误？您能否在使用PtrToStructure（）执行相反操作的地方发布代码，即将数据从非托管封送到托管封送。

Node
{
  public object key;
  public object value;
}

int[] cache = new int[200*8];
int[] PtrList = new int[200];
int m_node_length = System.Runtime.InteropServices.Marshal.SizeOf(typeof(Node));

fixed (byte* array = m_cache)
{
    for(int i = 0; i < PtrList.Length; i++)
        PtrList[i] = (int)new IntPtr(array + i * (m_node_length));
}

Node n = new Node();
n.key = a // a is int number
n.value = b // b is int number
IntPtr p = (IntPtr)PtrList[X]; // X >= 0 & X < 200
System.Runtime.InteropServices.Marshal.StructureToPtr(n, p, true);

The exception of the "System.ExecutionEngineException" type is not handled in the mscorlib.dll