以下是给出的答案:
1)这是我使用的解决方案:
private List<Overlay> mapOverlays;
private Projection projection;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
linearLayout = (LinearLayout) findViewById(R.id.zoomview);
mapView = (MapView) findViewById(R.id.mapview);
mapView.setBuiltInZoomControls(true);
mapOverlays = mapView.getOverlays();
projection = mapView.getProjection();
mapOverlays.add(new MyOverlay());
}
@Override
protected boolean isRouteDisplayed() {
return false;
}
class MyOverlay extends Overlay{
public MyOverlay(){
}
public void draw(Canvas canvas, MapView mapv, boolean shadow){
super.draw(canvas, mapv, shadow);
Paint mPaint = new Paint();
mPaint.setDither(true);
mPaint.setColor(Color.RED);
mPaint.setStyle(Paint.Style.FILL_AND_STROKE);
mPaint.setStrokeJoin(Paint.Join.ROUND);
mPaint.setStrokeCap(Paint.Cap.ROUND);
mPaint.setStrokeWidth(2);
GeoPoint gP1 = new GeoPoint(19240000,-99120000);
GeoPoint gP2 = new GeoPoint(37423157, -122085008);
Point p1 = new Point();
Point p2 = new Point();
Path path = new Path();
Projection projection.toPixels(gP1, p1);
projection.toPixels(gP2, p2);
path.moveTo(p2.x, p2.y);
path.lineTo(p1.x,p1.y);
canvas.drawPath(path, mPaint);
}
致谢:如何在Google地图上绘制线条/路径
2)以下是我实际使用的方法:
createMarkers()
{
for(elem:bigList)
{
GeoPoint geoPoint = new GeoPoint((int)(elem.getLat()*1000000), (int) (elem.getLon()*1000000));
OverlayItem overlayItem = new OverlayItem(geoPoint, elem.getName(), elem.getData());
itemizedOverlay.addOverlay(overlayItem);
}
itemizedOverlay.populateNow();
mapOverlays.add(itemizedOverlay); //outside of for loop
}
并且在MyOverlay中:
public void addOverlay(OverlayItem overlay)
{
m_overlays.add(overlay);
}
public void populateNow()
{
populate();
}
参考:stackoverflow.com 不知名链接
3) 最好的方法是使用计时器类。该链接详细描述了计时器类及其使用方法:
http://life.csu.edu.au/java-tut/essential/threads/timer.html
4) 我使用了以下代码:
if(!mapOverlays.isEmpty())
{
mapOverlays.clear();
mapView.invalidate();
}
希望这些答案能够帮助至少一个人。谢谢。