高效的地图叠加在Android的谷歌地图 [英] Efficient Map Overlays in Android Google Map
问题描述
我要做到以下几点和我对这些样卡了好几天:
-
我是想为绘制折线(我有恩codeD折线,而是设法去$ C C的$)的这一举动,当我移动地图。
我发现的唯一的解决办法是Geopoints要转换为屏幕坐标,如果我移动地图将不会移动。 -
我用
HelloItemizedOverlay
添加关于 150标记,它会非常非常慢。
任何想法怎么办?我在想线程(处理器)。 -
我一直在寻找某种的执行给定函数周期性,比如一个定时器功能,每隔1分钟左右。
-
我也在寻找各种方法来清除了谷歌地图的所有标记/行等。
下面给出答案:
1),下面是我用了一个解决方案:
/ **第一次创建活动时调用。 * /
私人名单,其中,叠加> mapOverlays;
私人投影的投影;
@覆盖
公共无效的onCreate(包savedInstanceState){
super.onCreate(savedInstanceState);
的setContentView(R.layout.main);
的LinearLayout =(的LinearLayout)findViewById(R.id.zoomview);
图形页面=(图形页面)findViewById(R.id.mapview);
mapView.setBuiltInZoomControls(真正的);
mapOverlays =调用MapView.getOverlays();
投影= MapView.getProjection()在;
mapOverlays.add(新MyOverlay());
}
@覆盖
保护的布尔isRouteDisplayed(){
返回false;
}
类MyOverlay扩展覆盖{
公共MyOverlay(){
}
公共无效画(油画画布,图形页面mapv,布尔影子){
super.draw(帆布,mapv,阴影);
油漆mPaint =新的油漆();
mPaint.setDither(真正的);
mPaint.setColor(Color.RED);
mPaint.setStyle(Paint.Style.FILL_AND_STROKE);
mPaint.setStrokeJoin(Paint.Join.ROUND);
mPaint.setStrokeCap(Paint.Cap.ROUND);
mPaint.setStrokeWidth(2);
的GeoPoint GP1 =新的GeoPoint(19240000,-99120000);
的GeoPoint GP2 =新的GeoPoint(37423157,-122085008);
点P1 =新的点();
点P2 =新的点();
路径path =新路径();
投影projection.toPixels(GP1,P1);
projection.toPixels(GP2,P2);
path.moveTo(p2.x,p2.y);
path.lineTo(p1.x,p1.y);
canvas.drawPath(路径,mPaint);
}
礼遇:借鉴谷歌地图线/路径
2)这里就是为我工作:
createMarkers()
{
对于(ELEM:bigList)
{
GeoPoint对象的GeoPoint =新的GeoPoint((INT)(elem.getLat()* 1000000),(INT)(elem.getLon()* 1000000));
OverlayItem overlayItem =新OverlayItem(的GeoPoint,elem.getName(),elem.getData());
itemizedOverlay.addOverlay(overlayItem);
}
itemizedOverlay.populateNow();
mapOverlays.add(itemizedOverlay); //为外循环
}
和在MyOverlay:
公共无效addOverlay(OverlayItem叠加)
{
m_overlays.add(叠加);
}
公共无效populateNow()
{
填充();
}
礼遇:stackoverflow.com不明链接
3)的最佳方法是使用一个计时器类。 Timer类的很详细的说明,以及如何使用它被赋予在此链接:
<一个href="http://life.csu.edu.au/java-tut/essential/threads/timer.html">http://life.csu.edu.au/java-tut/essential/threads/timer.html
4)我用这个code:
如果(!mapOverlays.isEmpty())
{
mapOverlays.clear();
mapView.invalidate();
}
希望这些答案可以帮助用于至少一个其他人。谢谢你。
I want to do the following and am kind of stuck on these for a few days:
I was trying to draw polylines (I have encoded polylines, but have managed to decode those) that move when I move the map.
The only solution that I found was for Geopoints to be transformed into screen coordinates... which won't move if I move the map.I used
HelloItemizedOverlay
to add about 150 markers and it gets very very slow.
Any idea what to do? I was thinking about threads (handler).I was looking for some sort of a timer function that executes a given function periodically, say, every 1 minute or so.
I was also looking for ways to clear the Google map from all the markers/lines, etc.
Answers given below :
1) Here's a solution that I used :
/** Called when the activity is first created. */
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);
}
courtesy: Drawing a line/path on Google Maps
2) Here's what worked for me :
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
}
and in MyOverlay:
public void addOverlay(OverlayItem overlay)
{
m_overlays.add(overlay);
}
public void populateNow()
{
populate();
}
courtesy: stackoverflow.com unknown link
3) The best way is to use a timer class. A very detailed description of the timer class and how to use it is given at this link :
http://life.csu.edu.au/java-tut/essential/threads/timer.html
4) I used this code :
if(!mapOverlays.isEmpty())
{
mapOverlays.clear();
mapView.invalidate();
}
Hope these answers help atleast one other person. Thanks.
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