尝试在AndroidStudio中绘制矩形矩阵。 没用

Question

I'm programming a mobile game, something like the Arkanoid game. I've started trying to draw a matrix made by rectangles, so I wrote a "for" which goes over the columns and other "for" within the first one which goes over the rows. When I execute the App, this just draw an only row. I don't know what's wrong. Help please!

     private void dibujarLadrillos(Canvas canvas, Paint paint)
{
    int width = 0;
    int height = 0;
    Rect[] ladrillos;

    for(int j = 0; j<= 2; j++) {
        ladrillos = new Rect[5];
        for (int i = 0; i <= ladrillos.length - 1; i++) {
            ladrillos[i] = new Rect(width, height, width + getWidth() / 5 - 10, height + getHeight()/10 );
            width += ladrillos[i].width() + 10;
            canvas.drawRect(ladrillos[i], paint);
        }
        height+= ladrillos[0].height() + 10;
    }
}

Answer 1

For each "j" you repeat the "i" loop.

So all but the last of the new Rect[5] you generate and fill are unreachable for you. The last one can be accessed via "ladrillos".

You need a 2-dimensional array like this:

Rect[][] ladrillos = new Rect[5][5];

The for loop has to be changed accordingly (I'm sure this needs some fine tuning but unfortunately I'm not familiar with Arkanoid ;-) )

for(int j = 0; j<= 2; j++) {
    for (int i = 0; i <= ladrillos[j].length - 1; i++) {
        ladrillos[j][i] = ...
        width += ladrillos[j][i].width() + 10;
        canvas.drawRect(ladrillos[j][i], paint);
    }
    height+= ladrillos[j][0].height() + 10;
}