Marshall double[] to IntPtr in C#?

Question

I am trying to convert double[] to IntPtr in C#. Here is the data I am going to convert:

double[] rotX = { 1.0, 0.0, 0.0 };
double[] rotY = { 0.0, 1.0, 0.0 };
double[] rotZ = { 0.0, 0.0, 1.0 };

Here is the function I am going to feed in the IntPtr, which is converted from the array above:

SetRotationDirection(IntPtr rotX, IntPtr rotY, IntPtr rotZ);

How should I do the job?

Answer 1

using System.Runtime.InteropServices;

/* ... */

double[] rotX = { 1.0, 0.0, 0.0 };
double[] rotY = { 0.0, 1.0, 0.0 };
double[] rotZ = { 0.0, 0.0, 1.0 };

var gchX = default(GCHandle);
var gchY = default(GCHandle);
var gchZ = default(GCHandle);

try
{
    gchX = GCHandle.Alloc(rotX, GCHandleType.Pinned);
    gchY = GCHandle.Alloc(rotY, GCHandleType.Pinned);
    gchZ = GCHandle.Alloc(rotZ, GCHandleType.Pinned);

    SetRotationDirection(
        gchX.AddrOfPinnedObject(),
        gchY.AddrOfPinnedObject(),
        gchZ.AddrOfPinnedObject());
}
finally
{
    if(gchX.IsAllocated) gchX.Free();
    if(gchY.IsAllocated) gchY.Free();
    if(gchZ.IsAllocated) gchZ.Free();
}