我目前正在根据不同的 GeoPoints 在 MapView 上绘制线条以指示扇区。使用以下代码(这是在覆盖范围内):
@Override
public void draw(Canvas canvas, MapView mapView, boolean shadow)
{
for(Polygon polygonTemp : polygonList)
{
Path p = new Path();
Projection projection = mapView.getProjection();
boolean firstTime = true;
for(GeoPoint geoPoint : polygonTemp.getGeoPointList())
{
Point drawPoint = new Point();
projection.toPixels(geoPoint, drawPoint);
if(firstTime)
{
p.moveTo(drawPoint.x, drawPoint.y);
firstTime = false;
}
else
{
p.lineTo(drawPoint.x, drawPoint.y);
}
}
p.setFillType(Path.FillType.EVEN_ODD);
Paint polyPaint = new Paint();
polyPaint.setStrokeWidth(1);
polyPaint.setStyle(Paint.Style.FILL_AND_STROKE);
polyPaint.setAntiAlias(true);
polyPaint.setColor(Color.parseColor(polygonTemp.getColor()));
canvas.drawPath(p, polyPaint);
firstTime = true;
}
super.draw(canvas, mapView, shadow);
}
问题是,我希望它们填充一定程度的透明度,所以我仍然可以看到填充扇区下的地图。我尝试将 polyPaint.setAlpha() 设置为 255(应该是完全透明的),但它什么也没做,完全不透明。
有人知道我在做什么错吗?