Drawing an empty polygon given a set of points on a Map Overylay (Android 2.1)

问题

I've set of n points and I want to draw a n-sided polygon using these points.

I tried using android.graphics.path (please see below).

Path path = new Path();
Vertex currVtx;

for (int j = 0; j < vertices.size(); j++) {
 currVtx = vertices.get(j);

 if (!currVtx.hasLatLong())
  continue;

 Point currentScreenPoint = getScreenPointFromGeoPoint(
   currVtx, mapview);
 if (j == 0)
  path.moveTo(currentScreenPoint.x, currentScreenPoint.y); 
          // vertex.
 else
  path.lineTo(currentScreenPoint.x, currentScreenPoint.y);

}

Currently I'm getting a solid (filled with the color of the canvas) polygon with this code. Is there a way that I can get an unfilled polygon. There is an alternative to android.graphics.Path

Thanks.

回答1:

Define a Paint object:

Paint mPaint = new Paint();
mPaint.setStrokeWidth(2);  //2 pixel line width
mPaint.setColor(0xFF097286); //tealish with no transparency
mPaint.setStyle(Paint.Style.STROKE); //stroked, aka a line with no fill
mPaint.setAntiAlias(true);  // no jagged edges, etc.

Then draw the path with:

yourCanvas.drawPath(path,mPaint);

You can look up the paint documentation but there are tons of options to control how its drawn.

来源：https://stackoverflow.com/questions/2815080/drawing-an-empty-polygon-given-a-set-of-points-on-a-map-overylay-android-2-1