Android mapView ItemizedOverlay setFocus无法正常工作

在ItemizedOverlay上调用setFocus(null)不会“取消聚焦”当前标记.根据文件：

… If the Item is not found, this is a no-op. You can also pass null to remove focus.

这是我的代码：

MapItemizedOverlay

public class MapItemizedOverlay extends ItemizedOverlay<OverlayItem> {
    private ArrayList<OverlayItem> items = new ArrayList<OverlayItem>();

    public MapItemizedOverlay(Drawable defaultMarker) {
        super(defaultMarker);
    }

    public void addOverlay(OverlayItem overlay) {
        items.add(overlay);
        populate();
    }

    @Override
    protected OverlayItem createItem(int i) {
        return items.get(i);
    }

    @Override
    public int size() {
        return items.size();
    }

}

创建地图叠加层和一个标记：

StateListDrawable youIcon = (StateListDrawable)getResources().getDrawable(R.drawable.marker_icon);
int width = youIcon.getIntrinsicWidth();
int height = youIcon.getIntrinsicHeight();
youIcon.setBounds(-13, 0-height, -13+width, 0);
GeoPoint location = new GeoPoint(40800816,-74122009);

MapItemizedOverlay overlay = new MapItemizedOverlay(youIcon);
OverlayItem item = new OverlayItem(location, "title", "snippet");
overlay.addOverlay(item);
mapView.getOverlays().add(overlay);

R.drawable.marker_icon定义如下：

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_focused="true" android:drawable="@drawable/marker_selected" />
    <item android:state_selected="true" android:drawable="@drawable/marker_selected" />
    <item android:drawable="@drawable/marker_normal" />
</selector>

现在,为了测试setFocus()行为,我将按钮放在活动窗口上,使用以下onClick监听器：

Button focusBtn = (Button)findViewById(R.id.focusbtn);
focusBtn.setOnClickListener(new OnClickListener() {             
    @Override
    public void onClick(View v) {
        for(Overlay ov : mapView.getOverlays())
        {
            if(ov.getClass().getSimpleName().equals("MapItemizedOverlay") == true)
            {
                MapItemizedOverlay miv = (MapItemizedOverlay)ov;
                if(miv.getFocus() == null)
                    miv.setFocus(miv.getItem(0));
                else
                    miv.setFocus(null);
                break;
            }
        }
        mapView.invalidate();
    }
});

预期的行为是：单击按钮切换标记选择.

它只工作一次 – 第一次单击它选择标记,再次单击它不会取消选择标记.最奇怪的是,在调用setFocus(null)之后,getFocus()也返回null – 就像overlay没有焦点项(我调试它).但即使在调用mapView.invalidate()之后,标记仍然以“选定”(聚焦)状态绘制.

解决方法:

正如Rpond在对我的问题的评论中所说,它看起来像API中的一个漏洞.

与此同时,我自己解决了这个问题.以下是变通方法代码.您需要扩展OverlayItem类并检查overlay.getFocus()返回的内容.

public class MapOverlayItem extends OverlayItem {

    MapItemizedOverlay overlay = null;

    public MapOverlayItem(GeoPoint point, MapItemizedOverlay ov)
    {
        super(point, null, null);
        this.overlay = ov;
    }

    public MapOverlayItem(GeoPoint point, String title, String snippet) {
        super(point, title, snippet);
    }

    @Override
    public Drawable getMarker(int stateBitset) {
        Drawable icon = overlay.getDefaultMarker();

        if(stateBitset == 0)
            return icon;

        OverlayItem focusedItem = overlay.getFocus();

        if(focusedItem == null) {
            OverlayItem.setState(icon, 0);
            return icon;
        }

        if(focusedItem.equals(this) == true)
            OverlayItem.setState(icon, stateBitset);
        else
            OverlayItem.setState(icon, 0);

        return icon;        
    }
}

标签：android,google-maps,setfocus,itemizedoverlay
来源： https://codeday.me/bug/20190726/1546298.html