How to draw a line in android

Question

Can anybody tell how to draw a line in Android, perhaps with an example?

Answer 1

There are two main ways you can draw a line, by using a Canvas or by using a View.

Drawing a Line with Canvas

From the documentation we see that we need to use the following method:

drawLine (float startX, float startY, float stopX, float stopY, Paint paint)

Here is a picture:

The Paint object just tells Canvas what color to paint the line, how wide it should be, and so on.

Here is some sample code:

private Paint paint = new Paint();
....

private void init() {
    paint.setColor(Color.BLACK);
    paint.setStrokeWidth(1f);
}

@Override
protected void onDraw(Canvas canvas) {
    super.onDraw(canvas);

    startX = 20;
    startY = 100;
    stopX = 140;
    stopY = 30;

    canvas.drawLine(startX, startY, stopX, stopY, paint);
}

Drawing a Line with View

If you only need a straight horizontal or vertical line, then the easiest way may be to just use a View in your xml layout file. You would do something like this:

Here is a picture with two lines (one horizontal and one vertical) to show what it would look like:

And here is the complete xml layout for that: