I have an object array containing array of a different type that is not known at compile time, but turns out to be int[], double[] etc.
I want to save these arrays to disk and I don't really need to process their contents online, so I looking for a way to cast the object[] to a byte[] that I then can write to disk.
How can I achieve this?
You may use binary serialization and deserialization for Serializable types.
using System.Runtime.Serialization.Formatters.Binary;
BinaryFormatter binary = BinaryFormatter();
using (FileStream fs = File.Create(file))
{
bs.Serialize(fs, objectArray);
}
Edit: If all these elements of an array are simple types then use BitConverter.
object[] arr = { 10.20, 1, 1.2f, 1.4, 10L, 12 };
using (MemoryStream ms = new MemoryStream())
{
foreach (dynamic t in arr)
{
byte[] bytes = BitConverter.GetBytes(t);
ms.Write(bytes, 0, bytes.Length);
}
}
MemoryStream instead of FileStream. You could add sample data in your post.BitConverter.GetBytes(for all simple types) method.You could do it the old fashioned way.
static void Main()
{
object [] arrayToConvert = new object[] {1.0,10.0,3.0,4.0, 1.0, 12313.2342};
if (arrayToConvert.Length > 0) {
byte [] dataAsBytes;
unsafe {
if (arrayToConvert[0] is int) {
dataAsBytes = new byte[sizeof(int) * arrayToConvert.Length];
fixed (byte * dataP = &dataAsBytes[0])
// CLR Arrays are always aligned
for(int i = 0; i < arrayToConvert.Length; ++i)
*((int*)dataP + i) = (int)arrayToConvert[i];
} else if (arrayToConvert[0] is double) {
dataAsBytes = new byte[sizeof(double) * arrayToConvert.Length];
fixed (byte * dataP = &dataAsBytes[0]) {
// CLR Arrays are always aligned
for(int i = 0; i < arrayToConvert.Length; ++i) {
double current = (double)arrayToConvert[i];
*((long*)dataP + i) = *(long*)¤t;
}
}
} else {
throw new ArgumentException("Wrong array type.");
}
}
Console.WriteLine(dataAsBytes);
}
}
However, I would recommend that you revisit your design. You should probably be using generics, rather than object arrays.
From here:
List<object> list = ...
byte[] obj = (byte[])list.ToArray(typeof(byte));
or if your list is complex type:
list.CopyTo(obj);
