如何在非托管内存中分配IntPtr []数组？

Question

To allocate memory in managed code i use:

IntPtr [] params_list_n = new IntPtr [5];

But for unmanaged memory i use Marshal.AllocHGlobal And I do not understand how, in this case to allocate memory for the array.

Ideally I want to use the function call Marshal.GetNativeVariantForObject (o, params_list_n[i]); For each element of the array.

Answer 1

Creating unmanaged memory using Marshal.AllocHGlobal is simple.

IntPtr pointer = Marshal.AllocHGlobal(1024);

If you need to calculate the amount of space you can use Marshal.SizeOf .

int size = Marshal.SizeOf(typeof(IntPtr));
IntPtr pointer = Marshal.AllocHGlobal(size);

You will also need to enable unsafe code in your project for this to run.

1. Right click on your project and select Properties .
2. Open the Build tab.
3. Select Allow unsafe code .

Answer 2

The array will be a pointer to the elements. You use it the same way:

IntPtr results = Marshal.AllocHGlobal(5 * IntPtr.Size);