I am using a 2D array to display Sudoku grids in command line and I want to change the colour of a number which is selected by the user through arrow keys. I have everything except the highlighting part.

Is there a way to change the colour of a selected number in a 2d array? Or would there be some other, more efficient way of doing that?

CodePudding user response：

Thank you all for your input, I have found the solution:

• Get position of the item to be highlighted
• Call the Display function again
• Add an if statement in the 2D array's for loop and pass it the coordinates
• Change the color in the if statement and change it right back again outside of it

Its not efficient and looks ugly but it works well.

Sorry I couldn't share the code.

CodePudding user response：

If you want an effect like this

then you have to handle it in the drawing routine.

The example above is done with

public class Matrix
{
    int[,] data;

    public Matrix(int rows, int columns)
    {
        Rows = rows;
        Columns = columns;
        data = new int[rows, columns];
    }

    internal int[,] Data => data;

    public int Rows { get; }
    public int Columns { get; }

    public ref int this[int row, int col]
        => ref data[row, col];

    public void DrawConsole(int rowCurrent, int colCurrent)
    {
        var fg = Console.ForegroundColor;
        var bk = Console.BackgroundColor;
        var curX = Console.CursorLeft;
        var curY = Console.CursorTop;

        const int width = 7;

        for (int i = 0; i < Rows; i  )
        {
            for (int j = 0; j < Columns; j  )
            {
                Console.SetCursorPosition(width * j   3, i * 2   2);
                Console.ForegroundColor = ConsoleColor.Gray;
                Console.BackgroundColor = ConsoleColor.Black;
                Console.Write(" ");
                if (i == rowCurrent && j == colCurrent)
                {
                    Console.ForegroundColor = ConsoleColor.Black;
                    Console.BackgroundColor = ConsoleColor.DarkCyan;
                }
                else
                {
                    Console.ForegroundColor = ConsoleColor.DarkBlue;
                    Console.BackgroundColor = ConsoleColor.Gray;
                }
                Console.Write(CenteredText(this[i, j].ToString(), width-1));
            }
        }

        Console.SetCursorPosition(curX, curY);
        Console.ForegroundColor = fg;
        Console.BackgroundColor = bk;
    }

    public static string CenteredText(string text, int width)
    {
        if (text.Length >= width) return text;
        int spaces = width- text.Length;
        return text.PadRight(spaces / 2   text.Length).PadLeft(width);
    }
}
class Program
{
    static void Main(string[] args)
    {
        var grid = new Matrix(9, 9);
        int index = 0;
        for (int i = 0; i < grid.Rows; i  )
        {
            for (int j = 0; j < grid.Columns; j  )
            {
                grid[i, j] =   index;
            }
        }

        grid.DrawConsole(3, 6);
    }
}

The if (i == rowCurrent && j == colCurrent) line branches off for the highlighted cell changing the display colors before writing the text out.