java Android - 在 MapView 上绘制路径作为叠加层
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Android - drawing path as overlay on MapView
提问by Rabas
I have a class that extends Overlay and implemments Overlay.Snappable. I have overriden its drawmethod:
我有一个扩展 Overlay 并实现 Overlay.Snappable 的类。我已经覆盖了它的draw方法：
@Override
public void draw(Canvas canvas, MapView mv, boolean shadow)
{
Projection projection = mv.getProjection();
ArrayList<GeoPoint> geoPoints = new ArrayList<GeoPoint>();
//Creating geopoints - ommited for readability
Path p = new Path();
for (int i = 0; i < geoPoints.size(); i++) {
if (i == geoPoints.size() - 1) {
break;
}
Point from = new Point();
Point to = new Point();
projection.toPixels(geoPoints.get(i), from);
projection.toPixels(geoPoints.get(i + 1), to);
p.moveTo(from.x, from.y);
p.lineTo(to.x, to.y);
}
Paint mPaint = new Paint();
mPaint.setStyle(Style.FILL);
mPaint.setColor(0xFFFF0000);
mPaint.setAntiAlias(true);
canvas.drawPath(p, mPaint);
super.draw(canvas, mv, shadow);
}
As you can see, I make a list of points on a map and I want them to form a polygonal shape.
正如你所看到的，我在地图上列出了一个点，我希望它们形成一个多边形。
Now, the problem is that when I set paint style to be FILL or FILL_AND_STROKE nothing shows up on the screen, but when I set it to be just stroke, and set stroke width, it acctually draws what it is supposed to draw.
现在，问题是当我将绘画样式设置为 FILL 或 FILL_AND_STROKE 时，屏幕上没有任何显示，但是当我将其设置为笔画并设置笔画宽度时，它实际上绘制了它应该绘制的内容。
Now, I looked for solution, but nothing comes up. Can you tell me if I something missed to set in the code itself, or are there some sorts of constraints when drawing on Overlay canvases?
现在，我寻找解决方案，但没有任何结果。你能告诉我我是否遗漏了代码本身的设置，或者在叠加画布上绘制时是否存在某种限制？
Thanks
谢谢
采纳答案by Soumya Simanta
A few things. You should use p.moveTo(from.x, from.y);only once i.e., first time when you want to do it for the first time.
一些东西。您应该p.moveTo(from.x, from.y);只使用一次，即，当您第一次想这样做时第一次使用。
Try this to set attributes for the paintobject used for painting the polygon.
试试这个来设置paint用于绘制多边形的对象的属性。
polygonPaint = new Paint();
polygonPaint.setStrokeWidth(2);
polygonPaint.setStyle(Paint.Style.STROKE);
polygonPaint.setAntiAlias(true);
Hope this helps.
希望这可以帮助。
