Converting 2 dimensional array to Single dimensional in C#?

Question

I am converting 2dimensional array to Single dimensional in C#. I receive the 2 dimensional array from device (C++) and then I convert it to 1 dimensional in C#. Here is my code:

int iSize = Marshal.SizeOf(stTransactionLogInfo); //stTransactionLogInfo is a structure
byte[,] bData = (byte[,])objTransLog; //objTransLog is 2 dimensionl array from device
byte[] baData = new byte[iSize];

for (int i = 0; i < bData.GetLength(0); i++)
{
    for (int j = 0; j < iSize; j++)
    {
        baData[j] = bData[i, j];
    }
}

I get the desired result from above code, but the problem is it is not the standard way of implementation. I want to know how it can be done in a standard way. May be doing Marshalling , I am not sure. Thanks in advance.

Solution 1

You can use the Buffer.BlockCopy Method:

byte[,] bData = (byte[,])objTransLog;

byte[] baData = new byte[bData.Length];

Buffer.BlockCopy(bData, 0, baData, 0, bData.Length);

---

Example:

byte[,] bData = new byte[4, 3]
{ 
    {  1,  2,  3 }, 
    {  4,  5,  6 }, 
    {  7,  8,  9 }, 
    { 10, 11, 12 } 
};

byte[] baData = new byte[bData.Length];

Buffer.BlockCopy(bData, 0, baData, 0, bData.Length);

// baData == { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 }

Solution 2

Simplest method

int iSize = Marshal.SizeOf(stTransactionLogInfo); //stTransactionLogInfo is a structure
byte[,] bData = (byte[,])objTransLog; //objTransLog is 2 dimensionl array from device
byte[] baData = bData.Cast<byte>().ToArray();

Solution 3

bData.Cast<byte>() will convert the multi-dimensional array to a single dimension.

This will do boxing, unboxing so isn't the most performant way, but is certainly the simplest and safest.

Solution 4

easy to understend and conver to a different language.

// Create 2D array (20 rows x 20 columns)
int row = 20; 
int column = 20;
int [,] array2D = new int[row, column];

// paste into array2D by 20 elements
int x = 0;  // row
int y = 0;  // column

for (int i = 0; i < my1DArray.Length; ++i)
{
     my2DArray[x, y] = my1DArray[i];
     y++;
     if (y == column)
     {
          y = 0;     // reset column
          x++;       // next row
     }
}

Solution 5

If 2-D array's column size is dynamic, below code is usable:

    public static T[] Convert2DArrayTo1D<T>(T[][] array2D)
    {
        List<T> lst = new List<T>();
        foreach(T[] a in array2D)
        {
            lst.AddRange(a);
        }
        return lst.ToArray();
    }

View more solutions

Comments

[Bokambo]

This is not giving me the desired result.Buffer.BlockCopy will be inside for loop ?

[Feidex]

I've added an example. A for loop is not needed.

[Bokambo]

Fine.Now the Problem is It will copy all the data at once. But I want data in blocks of My Structure size (suppose size is 270) because i am using this binary data to form My Structure.Structure consists of several fields that are getting filled with data and at the Last i am showing this data in a grid,Row by Row.

[Feidex]

So why aren't you using a stTransactionLogInfo[] instead of a byte[,]?

[MPaul]

What is the advantage of using the BlockCopy method as opposed to @Rakin 's answer? bData.Cast<byte>().ToArray();

[Nick Polyak]

The example works because it is a byte array. If you want some other types, e.g. integer arrays to work also, you need to get the byte length of the array int byteLength = Buffer.ByteLength(baData); and then pass it to the Buffer.BlockCopy as the last argument. The last argument should be the length in bytes not the length of the array.

[derHugo]

Adding to @NickPolyak ' comment: In general this only works for known base data types with a fix byte size. It will fail e.g. for string or any other dynamic sized type