地图

基本原理就是用ItemizedOverlay来附加物，在OnTap方法中向MapView上一个自定义的View（如果已存在就直接设为可见），下体来介绍我的实现方法：
　　一、自定义覆盖物类：MyPopupOverlay，这个类是最关键的一个类ItemizedOverlay，用于设置Marker，并定义Marker的点击，弹出窗口，至于弹出窗口的内容，则通过定义Listener，放到Activity中去构造。如果没有特殊需求，这个类不需要做什么改动。代如下，popupLinear这个对象，就是加到地图上的自定义View：
　　public class MyPopupOverlay extends ItemizedOverlay {

　　private Context context = null;
// 这是弹出窗口， 包括内容部分还有下面那个角
private LinearLayout popupLinear = null;
// 这是弹出窗口的内容部分
private View popupView = null;
private MapView mapView = null;
private Projection projection = null;
　　// 这是弹出窗口内容部分使用的layoutId，在Activity中设置
private int layoutId = 0;
// 是否使用百度带有A-J字样的Marker
private boolean useDefaultMarker = false;
private int[] defaultMarkerIds = { R.drawable.icon_marka,
R.drawable.icon_markb, R.drawable.icon_markc,
R.drawable.icon_markd, R.drawable.icon_marke,
R.drawable.icon_markf, R.drawable.icon_markg,
R.drawable.icon_markh, R.drawable.icon_marki,
R.drawable.icon_markj, };
　　// 这个Listener用于在Marker被点击时让Activity填充PopupView的内容
private OnTapListener onTapListener = null;
　　public MyPopupOverlay(Context context, Drawable marker, MapView mMapView) {
super(marker, mMapView);
this.context = context;
this.popupLinear = new LinearLayout(context);
this.mapView = mMapView;
popupLinear.setOrientation(LinearLayout.VERTICAL);
popupLinear.setVisibility(View.GONE);
projection = mapView.getProjection();
}
　　@Override
public boolean onTap(GeoPoint pt, MapView mMapView) {
// 点击窗口以外的区域时，当前窗口关闭
if (popupLinear != null && popupLinear.getVisibility() == View.VISIBLE) {
LayoutParams lp = (LayoutParams) popupLinear.getLayoutParams();
Point tapP = new Point();
projection.toPixels(pt, tapP);
Point popP = new Point();
projection.toPixels(lp.point, popP);
int xMin = popP.x - lp.width / 2 + lp.x;
int yMin = popP.y - lp.height + lp.y;
int xMax = popP.x + lp.width / 2 + lp.x;
int yMax = popP.y + lp.y;
if (tapP.x < xMin || tapP.y < yMin || tapP.x > xMax
|| tapP.y > yMax)
popupLinear.setVisibility(View.GONE);
}
return false;
}
　　@Override
protected boolean onTap(int i) {
// 点击Marker时，该Marker滑动到地图中央偏下的位置，并显示Popup窗口
OverlayItem item = getItem(i);
if (popupView == null) {
// 如果popupView还没有创建，则构造popupLinear
if (!createPopupView()){
return true;
}
}
if (onTapListener == null)
return true;
popupLinear.setVisibility(View.VISIBLE);
onTapListener.onTap(i, popupView);
　　popupLinear.measure(0, 0);
int viewWidth = popupLinear.getMeasuredWidth();
int viewHeight = popupLinear.getMeasuredHeight();
　　LayoutParams layoutParams = new LayoutParams(viewWidth, viewHeight,
item.getPoint(), 0, -60, LayoutParams.BOTTOM_CENTER);
layoutParams.mode = LayoutParams.MODE_MAP;
　　popupLinear.setLayoutParams(layoutParams);
Point p = new Point();
projection.toPixels(item.getPoint(), p);
p.y = p.y - viewHeight / 2;
GeoPoint point = projection.fromPixels(p.x, p.y);
　　mapView.getController().animateTo(point);
return true;
}
　　private boolean createPopupView() {
// TODO Auto-generated method stub
if (layoutId == 0)
return false;
popupView = LayoutInflater.from(context).inflate(layoutId, null);
popupView.setBackgroundResource(R.drawable.popupborder);
ImageView dialogStyle = new ImageView(context);
dialogStyle.setImageDrawable(context.getResources().getDrawable(
R.drawable.iw_tail));
popupLinear.addView(popupView);
android.widget.LinearLayout.LayoutParams lp = new android.widget.LinearLayout.LayoutParams(
LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT);
lp.topMargin = -2;
lp.leftMargin = 60;
popupLinear.addView(dialogStyle, lp);
mapView.addView(popupLinear);
return true;
}
　　@Override
public void addItem(List items) {
// TODO Auto-generated method stub
int startIndex = getAllItem().size();
for (OverlayItem item : items){
if (startIndex >= defaultMarkerIds.length)
startIndex = defaultMarkerIds.length - 1;
if (useDefaultMarker && item.getMarker() == null){
item.setMarker(context.getResources().getDrawable(
defaultMarkerIds[startIndex++]));
}
}
super.addItem(items);
}
　　@Override
public void addItem(OverlayItem item) {
// TODO Auto-generated method stub
// 重载这两个addItem方法，主要用于设置自己默认的Marker
int index = getAllItem().size();
if (index >= defaultMarkerIds.length)
index = defaultMarkerIds.length - 1;
if (useDefaultMarker && item.getMarker() == null){
item.setMarker(context.getResources().getDrawable(
defaultMarkerIds[getAllItem().size()]));
}
super.addItem(item);
}
　　public void setLayoutId(int layoutId) {
this.layoutId = layoutId;
}
　　public void setUseDefaultMarker(boolean useDefaultMarker) {
this.useDefaultMarker = useDefaultMarker;
}
　　public void setOnTapListener(OnTapListener onTapListener) {
this.onTapListener = onTapListener;
}
　　public interface OnTapListener {
public void onTap(int index, View popupView);
}
}