Converting DoubleArray To IntPtr and then to Byte Array

Question

Hi I have requirement to convert double array to IntPtr and this IntPtr to byte array. I want to do the reversal also just confirm values stored in byte array is of correct int array. The steps I am following is double[] dmanagedArray = new double[length]; for (int intI = 0; intI { dmanagedArray[intI] = intI * 10; } int size = Marshal.SizeOf(dmanagedArray[0]) * dmanagedArray.Length; IntPtr srcPtr1 = Marshal.AllocHGlobal(size); // This will copy double array to IntPtr. Marshal.Copy(dmanagedArray 0 srcPtr1 dmanagedArray.Length); // Now let's convert this IntPtr to byte array byte[] byteArray = new byte[dmanagedArray.Length] //Marshal.Copy(srcPtr1 byteArray 0 byteArray.Length); In my case what is happening is  byte[] now contains all the values as 0. which I think is wrong. How to do right conversion.

Nilesh Shah · Answer

Hi I think direct conversion of double array to byte array will always result in 0 this way. Because you need a byte[] to hold value of one double variable. So if you need to store value of doulbe[] then you will need two dimentional byte array i.e. byte[][]. Also you will need another double array to hold intermediate result as direct conversion of double[] to byte[][] is not possible. See following code which I modified from your code: int len = 5; double [] dmanagedArray = new double [len]; for ( int intI = 0; intI { dmanagedArray[intI] = intI * 10; } int size = Marshal.SizeOf(dmanagedArray[0]) * dmanagedArray.Length; IntPtr srcPtr1 = Marshal.AllocHGlobal(size); // This will copy double array to IntPtr. Marshal.Copy(dmanagedArray 0 srcPtr1 dmanagedArray.Length); double [] anotherDoubleArray = new double [len]; Marshal.Copy(srcPtr1 anotherDoubleArray 0 dmanagedArray.Length); byte [][] byteArray = new byte [dmanagedArray.Length][]; for ( int i = 0; i { byteArray[i] = BitConverter.GetBytes(anotherDoubleArray[i]); }