Question

I am using the drawpath function outside the ondraw function .I am calling this in my own function where I am calculating the screen co-ordinates.But draw path is not paiinting anything.

Is it true that the drawpath is functional only inside ondraw?

Answer 1

Yes, when you want to draw a Path you have to use a Canvas which you can only use in the onDraw(Canvas canvas) method. However it is possible to call you method from within the onDraw(Canvas canvas) method like this

@Override
public void onDraw(Canvas canvas) {
    drawPath(canvas);
}

public void drawPath(Canvas canvas) {

    Paint paint = new Paint();
    paint.setColor(Color.BLACK);

    Path path = new Path();
    path.moveTo(4, -10);
    path.lineTo(20, 0);
    path.lineTo(-9, 0);
    path.close();

    canvas.drawPath(path, paint);
}

see also How to use canvas in your android apps for more information on Path