fr****@terra.com.br wrote:
With Marshal you can copy data from a one-dimensional array to
BitmapData.Scan0.
What do I do if my array is two-dimensional?
Or, alternatively, can I create somehow two variables
byte[] arr1; // size 480*640
byte[,] arr2; // size [480,640]
which are references to the same memory block and allow me to access
it at will with one or two indices, e.g. arr1[640] or arr2[1,0]?
Hi Frank. Because arrays in C# are not pointer-based, unlike in C, it is not
possible to have two arrays share the same underlying data (and in fact, I'm
not sure if multidimensional arrays even have a linear memory
representation). However, one simple solution that achieves a similar effect
is to create a class that wraps a one-dimensional array and performs index
calculations for you in an indexer like this:
public class Array2D<T> {
T[] a;
int columns;
public Array2D(int rows, int columns) {
this.columns = columns;
this.a = new T[rows * columns];
}
public T this[int row, int column] {
get {
return a[row * columns + column];
}
set {
a[row * columns + column] = value;
}
}
public T[] ToArray() {
return a;
}
}
This code is untested and uses generics, a feature of C# 2.0, but you could
use "object" in place of T at the expense of type safety and added casts.
You simply use it like a normal two-dimensional array until you want the
underlying one-dimensional array, then you call ToArray(). If the calls are
inlined, the efficiency hit should be relatively small. I hope this helps.
--
Derrick Coetzee, MCP, MSFT (Speech Server)
This posting is provided "AS IS" with no warranties, and confers no
rights. Use of included code samples are subject to the terms
specified at
http://www.microsoft.com/info/cpyright.htm 
