C#将指针作为参数传递不安全代码

using System;

namespace UnsafeCodeApplication {

   class TestPointer {

      public unsafe void swap(int* p, int *q) {
         int temp = *p;
         *p = *q;
         *q = temp;
      }

      public unsafe static void Main() {
         TestPointer p = new TestPointer();
         int var1 = 10;
         int var2 = 20;
         int* x = &var1;
         int* y = &var2;

         Console.WriteLine("Before Swap: var1:{0}, var2: {1}", var1, var2);
         p.swap(x, y);

         Console.WriteLine("After Swap: var1:{0}, var2: {1}", var1, var2);
         Console.ReadKey();
      }
   }
}