android 获取地图中心点的经纬度坐标

最近项目中需要让用户在 地图上选择 商户的位置，需要有一个图标一直在屏幕的正中央，然后用户拖动地图的时候，动态解析中心点的地址信息，效果图如下：



废话不多说了，直接上代码吧

界面布局文件 select_shoplocation.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >

<RelativeLayout
android:id="@+id/rl_topbar"
android:layout_width="match_parent"
android:layout_height="@dimen/list_topbar_height"
android:background="@drawable/list_bar" >

<Button
android:id="@+id/bt_back"
android:layout_width="35dp"
android:layout_height="35dp"
android:layout_alignParentLeft="true"
android:layout_centerVertical="true"
android:layout_marginLeft="@dimen/list_topbar_margin"
android:layout_marginRight="@dimen/favorite_op_margin"
android:background="@drawable/list_icon_back" />

<TextView
android:id="@+id/tv_map_title"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:layout_centerVertical="true"
android:text="@string/know_shop"
android:textColor="@color/white"
android:textSize="22sp" />

<Button
android:id="@+id/bt_save"
android:layout_width="35dp"
android:layout_height="35dp"
android:layout_alignParentRight="true"
android:layout_centerVertical="true"
android:layout_marginLeft="@dimen/list_topbar_margin"
android:layout_marginRight="@dimen/favorite_op_margin"
android:background="@drawable/icon_ok" />
</RelativeLayout>

<RelativeLayout
android:layout_width="fill_parent"
android:layout_height="0dp"
android:layout_weight="1" >

<com.yulore.yellowpage.view.MyMapView
android:id="@+id/mapView"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:apiKey="@string/maps_api_key"
android:clickable="true" />

<com.yulore.yellowpage.view.MyCenterPoint
android:id="@+id/bt_mapCenter"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"/>

</RelativeLayout>

<RelativeLayout
android:layout_width="fill_parent"
android:layout_height="50dp"
android:background="#3D3F49" >

<TextView
android:id="@+id/tv_address"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerVertical="true"
android:layout_marginLeft="15dp"
android:textColor="@color/white"
android:textSize="13sp" />
</RelativeLayout>

</LinearLayout>

这里我自定义了两个View：MyMapView、MyCenterPoint，MyMapView继承自 MapView，因为我们需要拦截触摸事件。

MyMapView.java 

import android.content.Context;
import android.util.AttributeSet;
import android.view.MotionEvent;
import com.mapabc.mapapi.core.GeoPoint;
import com.mapabc.mapapi.map.MapView;

public class MyMapView extends MapView {
private OnMapViewChangedListener mListener;

public void setOnMapViewChangedListener(OnMapViewChangedListener mListener) {
this.mListener = mListener;
}

public MyMapView(Context arg0, AttributeSet arg1) {
super(arg0, arg1);
// TODO Auto-generated constructor stub
}

public MyMapView(Context arg0, AttributeSet arg1, int arg2) {
super(arg0, arg1, arg2);
// TODO Auto-generated constructor stub
}

public MyMapView(Context arg0, String arg1, String arg2) {
super(arg0, arg1, arg2);
// TODO Auto-generated constructor stub
}

public MyMapView(Context arg0, String arg1) {
super(arg0, arg1);
// TODO Auto-generated constructor stub
}

@Override
public boolean onTouchEvent(MotionEvent arg0) {

GeoPoint g = this.getProjection().fromPixels(MyCenterPoint.w, MyCenterPoint.h);

if(mListener!=null)
mListener.onMapViewChanged(g);

return super.onTouchEvent(arg0);
}
/**
* 回调接口
* @author FX_SKY
*
*/
public interface OnMapViewChangedListener{

public void onMapViewChanged(GeoPoint point);
}

}

MyCenterPoint.java

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.util.AttributeSet;
import android.view.View;

import com.yulore.yellowpage.R;

public class MyCenterPoint extends View {

public static int w;
public static int h;
public static  Bitmap mBitmap;

public MyCenterPoint(Context context) {
super(context);
}

public MyCenterPoint(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}

public MyCenterPoint(Context context, AttributeSet attrs) {
super(context, attrs);
}

@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);

mBitmap = BitmapFactory.decodeResource(getResources(), R.drawable.icon_map);

w = this.getWidth() / 2 - mBitmap.getWidth() / 2;
h = this.getHeight() / 2 - mBitmap.getHeight() / 2;
canvas.drawBitmap(mBitmap, w, h, null);
}

}

地图界面 SelectLocationActivity

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;

import android.app.ProgressDialog;
import android.content.Context;
import android.content.Intent;
import android.graphics.Canvas;
import android.graphics.drawable.Drawable;
import android.location.Address;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.KeyEvent;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.RelativeLayout;
import android.widget.TextView;
import android.widget.Toast;

import com.mapabc.mapapi.core.GeoPoint;
import com.mapabc.mapapi.core.MapAbcException;
import com.mapabc.mapapi.core.OverlayItem;
import com.mapabc.mapapi.geocoder.Geocoder;
import com.mapabc.mapapi.map.ItemizedOverlay;
import com.mapabc.mapapi.map.MapActivity;
import com.mapabc.mapapi.map.MapController;
import com.mapabc.mapapi.map.MapView;
import com.umeng.analytics.MobclickAgent;
import com.yulore.yellowpage.http.BaseTask;
import com.yulore.yellowpage.http.NetUtil;
import com.yulore.yellowpage.http.RequestVo;
import com.yulore.yellowpage.parser.ResultParser;
import com.yulore.yellowpage.util.CommonUtil;
import com.yulore.yellowpage.util.Constant;
import com.yulore.yellowpage.util.LogUtil;
import com.yulore.yellowpage.util.ThreadPoolManager;
import com.yulore.yellowpage.view.MyCenterPoint;
import com.yulore.yellowpage.view.MyMapView;
import com.yulore.yellowpage.view.MyMapView.OnMapViewChangedListener;

/**
* 显示店铺位置 界面
*
* @author feng bingbing
*
*/
public class SelectLocationActivity extends MapActivity implements
OnClickListener {

private static final String TAG = SelectLocationActivity.class
.getSimpleName();
private MyMapView mMapView;
private MapController mMapController;
private ProgressDialog mProgressDialog = null;
double lat = 0.0f, lng = 0.0f;
double oldLat = 0.0f, oldLng = 0.0f;
private Geocoder coder;// 逆地理编码
private Handler handler = new Handler() {
public void handleMessage(android.os.Message msg) {
switch (msg.what) {
case Constant.QUERY_ADDRESS_SUCCESS:

address = (String) msg.obj;
if (address != null) {
tv_address.setText(address.concat("( ")
.concat(String.format("%.6f", lat)).concat(",")
.concat(String.format("%.6f", lng)).concat(" )"));
}

break;
case Constant.QUERY_ADDRESS_FAILED:
Toast.makeText(getApplicationContext(),
R.string.map_query_address_failed, 0).show();
break;

case Constant.REQUEST_SERVER_SUCCESS:
mProgressDialog.dismiss();
String result = msg.obj.toString();
if (result.equals("0")) {
Toast.makeText(getApplicationContext(), "您的更改已经提交成功",
Toast.LENGTH_SHORT).show();
finish();
overridePendingTransition(R.anim.back_left_in,
R.anim.back_right_out);
} else {
Toast.makeText(getApplicationContext(), "提交失败，请稍后重新提交",
Toast.LENGTH_SHORT).show();
}

break;

default:
if (mProgressDialog != null && mProgressDialog.isShowing()) {
mProgressDialog.dismiss();
}
break;
}
};
};
private TextView tv_address;
private int type;
private TextView tv_map_title;
private Button bt_save;
private Button bt_back;
private RelativeLayout rl_topbar;
private String address;
private String shopId;
private MyCenterPoint bt_mapCenter;

@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.select_shoplocation);

LogUtil.i(TAG, "onCreate");

findView();

Intent intent = getIntent();
if (intent != null) {
String location = intent.getStringExtra("location");

if (location != null && location.length() > 0) {
String[] arr = location.split(",");
lat = Double.parseDouble(arr[0]);
lng = Double.parseDouble(arr[1]);
oldLat = lat;
oldLng = lng;
}

type = intent.getIntExtra("type", 1);
address = intent.getStringExtra("address");

if (address != null) {
tv_address.setText(address.concat("( ")
.concat(String.valueOf(lat)).concat(",")
.concat(String.valueOf(lng)).concat(" )"));
}

shopId = intent.getStringExtra("shopId");
}

LogUtil.i(TAG, "onCreate:" + lat + ">>" + lng);

mMapView.setVectorMap(true);
mMapView.setBuiltInZoomControls(true);
mMapController = mMapView.getController();

coder = new Geocoder(this, getResources().getString(
R.string.maps_api_key)); // 根据给定的API Key 构造Geocoder 对象

mMapController.setZoom(15);
// 设为当前位置显示
GeoPoint p1 = new GeoPoint((int) (lat * 1E6), (int) (lng * 1E6));

switch (type) {
case 1: // 详情
rl_topbar.setBackgroundResource(R.drawable.bar);
bt_back.setBackgroundResource(R.drawable.icon_back);
tv_map_title.setText("商户位置");
tv_map_title.setTextColor(getResources().getColorStateList(
R.color.black));
bt_save.setVisibility(View.GONE);
bt_mapCenter.setVisibility(View.GONE);

if(lat>0 && lng>0){
newOverlay(lat, lng);
}else{
Toast.makeText(getApplicationContext(), "经纬度坐标信息有误", Toast.LENGTH_LONG).show();
}

break;
case 2: // 纠错
tv_map_title.setText("商户位置错误");
bt_save.setVisibility(View.VISIBLE);

mMapController.setCenter(p1); // 设置地图中心点
mMapController.setCenter(p1); // 设置地图中心点
mMapView.setOnMapViewChangedListener(new MyOnMapViewChangedListener());

if(lat>0 && lng>0){
reverseAddress(lat, lng);
}else{
Toast.makeText(getApplicationContext(), "经纬度坐标信息有误", Toast.LENGTH_LONG).show();
}

break;
case 3: // 我知道商户
tv_map_title.setText("请选择商户位置");
bt_save.setVisibility(View.VISIBLE);

mMapController.setCenter(p1); // 设置地图中心点
mMapView.setOnMapViewChangedListener(new MyOnMapViewChangedListener());

//初始化 地图中心点
if(lat>0 && lng>0){
reverseAddress(lat, lng);
}else{
Toast.makeText(getApplicationContext(), "经纬度坐标信息有误", Toast.LENGTH_LONG).show();
}
break;
default:
break;
}

}

private class MyOnMapViewChangedListener implements
OnMapViewChangedListener {

@Override
public void onMapViewChanged(GeoPoint point) {

if (point != null) {
lat = (float) (point.getLatitudeE6() / 1E6);
lng = (float) (point.getLongitudeE6() / 1E6);

// LogUtil.i(TAG, "lat:" + lat + ",lng" + lng);

reverseAddress(lat,lng);
}
}
}

/**
* 根据经纬度 解析地址信息
* @param lat
* @param lng
*/
private void reverseAddress(final double lat, final double lng) {

Runnable task = new Runnable() {

@Override
public void run() {
try {
List<Address> list = coder.getFromLocation(lat,
lng, 3);

StringBuffer sb = new StringBuffer();

if (list != null && list.size() > 0) {
Address address = list.get(0);
String adminArea = address.getAdminArea();
String locality = address.getLocality();
String subLocality = address.getSubLocality();
String feature = address.getFeatureName();

sb.append(adminArea).append(locality)
.append(subLocality).append(feature);

// LogUtil.e(TAG, "adminArea:" + adminArea
// + ",locality:" + locality + ",subLocality:"
// + subLocality + ",feature:" + feature);
}

Message msg = Message.obtain();
msg.what = Constant.QUERY_ADDRESS_SUCCESS;
msg.obj = sb.toString();
handler.sendMessage(msg);

} catch (MapAbcException e) {
e.printStackTrace();
handler.sendEmptyMessage(Constant.QUERY_ADDRESS_FAILED);
}
}
};
ThreadPoolManager.getInstance().addTask(task);
}

public void onResume() {
super.onResume();
MobclickAgent.onResume(this);
}

public void onPause() {
super.onPause();
MobclickAgent.onPause(this);
}

public void newOverlay(double lat, double lng) {

mMapView.getOverlays().clear();
Drawable marker = null;
if (type == 1) {
marker = getResources().getDrawable(R.drawable.icon_map_local); // 得到需要标在地图上的资源
} else {
marker = getResources().getDrawable(R.drawable.icon_map); // 得到需要标在地图上的资源
}

marker.setBounds(0, 0, marker.getIntrinsicWidth(),
marker.getIntrinsicHeight()); // 为maker定义位置和边界
mMapView.getOverlays().add(new OverItemT(marker, this)); // 添加ItemizedOverlay实例到mMapView

// 设为当前位置显示
GeoPoint p1 = new GeoPoint((int) (lat * 1E6), (int) (lng * 1E6));
// mMapController.animateTo(p1);
mMapController.setCenter(p1); // 设置地图中心点

}

private void findView() {
mMapView = (MyMapView) findViewById(R.id.mapView);
bt_back = (Button) findViewById(R.id.bt_back);
bt_save = (Button) findViewById(R.id.bt_save);
rl_topbar = (RelativeLayout) findViewById(R.id.rl_topbar);
bt_mapCenter = (MyCenterPoint) findViewById(R.id.bt_mapCenter);

tv_address = (TextView) findViewById(R.id.tv_address);
tv_map_title = (TextView) findViewById(R.id.tv_map_title);

bt_back.setOnClickListener(this);
bt_save.setOnClickListener(this);
}

/**
* 分条目覆盖物。当某个类型的覆盖物，包含多个类型相同、显示方式相同、处理方式相同的项时，使用此类。
*/
class OverItemT extends ItemizedOverlay<OverlayItem> {
private List<OverlayItem> GeoList = new ArrayList<OverlayItem>();
private Drawable marker;
private Context mContext;

public OverItemT(Drawable marker, Context context) {
super(boundCenterBottom(marker));
this.marker = marker;
this.mContext = context;
// 用给定的经纬度构造GeoPoint，单位是微度（度 * 1E6）
GeoPoint p1 = new GeoPoint((int) (lat * 1E6), (int) (lng * 1E6));
// 构造OverlayItem的三个参数依次为：item的位置，标题文本，文字片段
GeoList.add(new OverlayItem(p1, "", ""));
populate(); // createItem(int)方法构造item。一旦有了数据，在调用其它方法前，首先调用这个方法
}

@Override
public void draw(Canvas canvas, MapView mapView, boolean shadow) {

super.draw(canvas, mapView, false);
// 调整一个drawable边界，使得(0,0)是这个drawable底部最后一行中心的一个像素
boundCenterBottom(marker);
}

@Override
protected OverlayItem createItem(int i) {
// TODO Auto-generated method stub
return GeoList.get(i);
}

@Override
public int size() {
// TODO Auto-generated method stub
return GeoList.size();
}

@Override
public boolean onTap(GeoPoint point, MapView mapView) {

return super.onTap(point, mapView);
}
}

private HashMap<String, String> toJsonStr() {
HashMap<String, String> map = new HashMap<String, String>();
map.put("errortype", "mAddress");
map.put("shopid", shopId);
map.put("system", "2");
map.put("version",
CommonUtil.getAppVersionCode(getApplicationContext()));
map.put("uid", CommonUtil.getDeviceID(getApplicationContext()));
map.put("lat", String.valueOf(lat));
map.put("lng", String.valueOf(lng));
return map;
}

private void postData() {
mProgressDialog = new ProgressDialog(this);
mProgressDialog.setMessage("正在提交...");
mProgressDialog.setIndeterminate(false);
mProgressDialog.setMax(100);
mProgressDialog.setProgressStyle(ProgressDialog.STYLE_SPINNER);
mProgressDialog.setCancelable(false);
mProgressDialog.setCanceledOnTouchOutside(false);
mProgressDialog.show();
RequestVo requestVo = new RequestVo();
requestVo.context = getApplicationContext();
requestVo.requestUrl = Constant.APP_HOST
.concat(Constant.CORRECTION_INFO);
requestVo.jsonParser = new ResultParser();
requestVo.requestDataMap = toJsonStr();
requestVo.type = 1;
BaseTask task = new BaseTask(getApplicationContext(), requestVo,
handler);
ThreadPoolManager.getInstance().addTask(task);
}

@Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.bt_back:
this.finish();
overridePendingTransition(R.anim.back_left_in,
R.anim.back_right_out);
break;
case R.id.bt_save:
if (type == 2) {
if (oldLat != lat || oldLng != lng) {
if (NetUtil.hasNetwork(getApplicationContext())) {
postData();
} else {
Toast.makeText(getApplicationContext(), "网络环境不可用",
Toast.LENGTH_SHORT).show();
}
} else {
Toast.makeText(getApplicationContext(), "您的更改已经提交成功",
Toast.LENGTH_SHORT).show();
finish();
overridePendingTransition(R.anim.back_left_in,
R.anim.back_right_out);
}
} else {
Intent data = new Intent();
data.putExtra("address", address);
data.putExtra("lat", lat);
data.putExtra("lng", lng);
setResult(Constant.REQUEST_MAP_ADDRESS, data);

this.finish();
overridePendingTransition(R.anim.back_left_in,
R.anim.back_right_out);
}

break;

default:
break;
}
}

// 处理后退键的情况
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_BACK) {
this.finish(); // finish当前activity
// 设置切换动画，从上边进入，下边退出
overridePendingTransition(R.anim.back_left_in,
R.anim.back_right_out);
return true;
}
return super.onKeyDown(keyCode, event);
}
}


这里我使用的是Mapabc地图，其他的像 Baidu、Google 实现方式都是类似的，这里不贴了，有兴趣的同学 自己可以实现。