float[] m = new float[6];
int size = sizeof(float) * m.Length;
IntPtr ptr = Marshal.AllocHGlobal(size);
Marshal.Copy(m, 0, ptr, m.Length);

------解决方案--------------------
float[]a={0.231,0.154};
IntPtr p;
Marshal.Copy(a,0,p,a.Length);

------解决方案--------------------
C# code
            float[] f = new float[] {1f,2f,3f};
            unsafe
            {
                fixed (float* pf = f)
                {
                    IntPtr address = new IntPtr(pf);
                }
            }

------解决方案--------------------
float[] f = new float[10];
           IntPtr[] intptr = f.Select(t => new IntPtr(Convert.ToInt32(t))).ToArray();