如何访问大小不同的字节数组？

Question

i facing a problem when i try to access to an array of array with a pointer, i have several arrays declared as following :

BYTE a[5] = {0xcc,0xaa,0xbb,0xcc,0xff};
BYTE b[3] = {0xaa,0xbb,0xff};

thos BYTE arrays represents image that i want to load in memory from a dll, i can access them separately with no difficulty, but i want to access them from a loop with a pointer ...

i tried to put them into an array of array like this :

BYTE* c[2] = {a,b};

but when i want to loop through this pointer c[i] doesent load image at i index into memory, how could i fix it?

im trying to draw images with this method within a loop to avoid repating lines ( consider c is images[i])

void MenuIcon::drawIcons(LPDIRECT3DDEVICE9 npDevice)
{
    isMenuVisible = (Pos.x < 100) && (Pos.x > 0)?  true : false;

    if(isMenuVisible)
    for (int i = 0; i < 2; i++)
    {
        if (icon[i].img == NULL)D3DXCreateTextureFromFileInMemory(npDevice, &images[i], sizeof(images[i]), &icon[i].img);
        DrawTexture(icon[i].coord.x, icon[i].coord.y, icon[i].img);
    }

}

i try to use my method like this after reading your answer :

 void MenuIcon::drawIcons(LPDIRECT3DDEVICE9 npDevice)
{
    isMenuVisible = (Pos.x < 100) && (Pos.x > 0)?  true : false;

    if(isMenuVisible)
    for (size_t i = 0; i < images.size(); i++)
    {

        std::vector<BYTE>& curArray = images[i];
        if (icon[i].img == NULL)D3DXCreateTextureFromFileInMemory(npDevice, &curArray, curArray.size(), &icon[i].img);
        DrawTexture(icon[i].coord.x, icon[i].coord.y, icon[i].img);
    }

}

but it still not drawing nothing .... maybe &curArray is not called proprely?? NB -> i logged both image and size of arrayofarray and it return me correct values....

Answer 1

You can use std::vector :

#include <vector>
#include <iostream>
#include <iomanip>

typedef int BYTE;
typedef std::vector<BYTE> ByteArray;
typedef std::vector<ByteArray> ArrayOfByteArray;

using namespace std;

int main()
{
   // fill our array
   ArrayOfByteArray c = {{0xcc,0xaa,0xbb,0xcc,0xff}, 
                         {0xaa,0xbb,0xff}
                         // add more as desired...
                         };

   // loop on each entry
   for (size_t i = 0; i < c.size(); i++)
   {
      // get the byte array for entry i
      std::vector<BYTE>& curArray = c[i];

      // output the values found for this array
      for (size_t j = 0; j < curArray.size(); ++j)
         cout << std::hex << curArray[j] << " ";

      cout << "\n";
   }
}

Live Example

The std::vector knows the sizes of each of the entries, unlike an array.

Take the code here and add to it to suit what you're attempting to do with the images.