基于位置的服务——百度地图SDK练习

时间 2020-06-02

标签基于位置服务百度地图 sdk 练习繁體版

原文原文链接

基于位置的服务所围绕的核心就是要先肯定出用户所在的位置。一般有两种技术方式能够实现：一种是经过GPS定位，一种是经过网络定位。Android对这两种定位方式都提供了相应的API支持。但因为众所周知的缘由，Google的网络服务不能使用，而GPS定位必需要在室外才能够使用。因此使用了国内第三方公司——百度的SDK。java

首先是申请百度地图API Key，以后下载SDK，将解压的文件放到下图所示的位置。android

接下来直接放代码：git

AndroidManifest.xml——用户权限：
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.lbstest">
    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
    <uses-permission android:name="android.permission.ACCESS_WIFI_STATE"/>
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
    <uses-permission android:name="android.permission.ACCESS_CHANGE_WIFI_STATE"/>
    <uses-permission android:name="android.permission.READ_PHONE_STATE"/>
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
    <uses-permission android:name="android.permission.INTERNET"/>
    <uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS"/>
    <uses-permission android:name="android.permission.WAKE_LOCK"/>

    <application android:allowBackup="true" android:icon="@mipmap/ic_launcher" android:label="@string/app_name" android:roundIcon="@mipmap/ic_launcher_round" android:supportsRtl="true" android:theme="@style/AppTheme">
        <meta-data android:name="com.baidu.lbsapi.API_KEY" android:value="A07VXXmueNToMFnf6q7xXBjHfyDc1sGA"/>
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

        <service android:name="com.baidu.location.f" android:enabled="true" android:process=":remote">
        </service>
    </application>


</manifest>

其中android:value=”A07VXXmueNToMFnf6q7xXBjHfyDc1sGA”是申请后由百度提供的API Key。api

activity_main.xml——布局文件：
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.example.lbstest.MainActivity">

    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:orientation="vertical"
        android:layout_width="368dp"
        android:layout_height="495dp"
        tools:layout_editor_absoluteY="8dp"
        tools:layout_editor_absoluteX="8dp">
        <TextView
            android:id="@+id/position_text_view"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:visibility="gone"/>

        <com.baidu.mapapi.map.MapView
            android:id="@+id/bmapView"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:clickable="true"/>
    </LinearLayout>
</android.support.constraint.ConstraintLayout>

MainActivity.java：
package com.example.lbstest;

import android.Manifest;
import android.content.pm.PackageManager;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.TextView;
import android.widget.Toast;

import com.baidu.location.BDLocation;
import com.baidu.location.BDLocationListener;
import com.baidu.location.LocationClient;
import com.baidu.location.LocationClientOption;
import com.baidu.mapapi.SDKInitializer;
import com.baidu.mapapi.map.BaiduMap;
import com.baidu.mapapi.map.MapStatus;
import com.baidu.mapapi.map.MapStatusUpdate;
import com.baidu.mapapi.map.MapStatusUpdateFactory;
import com.baidu.mapapi.map.MapView;
import com.baidu.mapapi.map.MyLocationData;
import com.baidu.mapapi.model.LatLng;

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

public class MainActivity extends AppCompatActivity {
    public LocationClient mLocationClient;
    private TextView positionText;
    private MapView mapView;
    private BaiduMap baiduMap;
    private boolean isFirstLocate=true;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        mLocationClient = new LocationClient(getApplicationContext());
        mLocationClient.registerLocationListener(new MyLocationListener());
        SDKInitializer.initialize(getApplicationContext());
        setContentView(R.layout.activity_main);
        mapView=(MapView) findViewById(R.id.bmapView);
        baiduMap=mapView.getMap();
        baiduMap.setMyLocationEnabled(true);
        positionText = (TextView) findViewById(R.id.position_text_view);
        List<String> permissionList = new ArrayList<>();
        if (ContextCompat.checkSelfPermission(MainActivity.this, Manifest.
                permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
            permissionList.add(Manifest.permission.ACCESS_FINE_LOCATION);
        }
        if (ContextCompat.checkSelfPermission(MainActivity.this, Manifest.
                permission.READ_PHONE_STATE) != PackageManager.PERMISSION_GRANTED) {
            permissionList.add(Manifest.permission.READ_PHONE_STATE);
        }
        if (ContextCompat.checkSelfPermission(MainActivity.this, Manifest.
                permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
            permissionList.add(Manifest.permission.WRITE_EXTERNAL_STORAGE);
        }
        if (!permissionList.isEmpty()) {
            String[] permission = permissionList.toArray(new String[permissionList.size()]);
            ActivityCompat.requestPermissions(MainActivity.this, permission, 1);
        } else {
            requestLocation();
        }
    }

    private void requestLocation() {
        initLocation();
        mLocationClient.start();
        mLocationClient.requestLocation();
    }
    private void initLocation(){
        LocationClientOption option=new LocationClientOption();
        option.setScanSpan(5000);
        option.setIsNeedAddress(true);
        mLocationClient.setLocOption(option);
    }
    @Override
    protected void onResume(){
        super.onResume();
        mapView.onResume();
    }
    @Override
    protected void onPause(){
        super.onPause();
        mapView.onPause();
    }
    @Override
    protected void onDestroy(){
        super.onDestroy();
        mLocationClient.stop();
        mapView.onDestroy();
        baiduMap.setMyLocationEnabled(false);
    }
    @Override
    public void onRequestPermissionsResult(int requestCode,String[] permission,int[] grantResults) {
        switch (requestCode) {
            case 1:
                if (grantResults.length > 0) {
                    for (int result : grantResults) {
                        if (result != PackageManager.PERMISSION_GRANTED) {
                            Toast.makeText(this, "必须赞成全部权限才能使用本程序",
                                    Toast.LENGTH_SHORT).show();
                            finish();
                            return;
                        }
                    }
                    requestLocation();
                } else {
                    Toast.makeText(this, "发生未知错误", Toast.LENGTH_SHORT).show();
                    finish();
                }
                break;
            default:
        }
    }
    private void navigateTo(BDLocation location){
        if (isFirstLocate){
            LatLng ll=new LatLng(location.getLatitude(),location.getLongitude());
            MapStatusUpdate update= MapStatusUpdateFactory.newLatLng(ll);
            baiduMap.animateMapStatus(update);
            update=MapStatusUpdateFactory.zoomTo(16f);
            baiduMap.animateMapStatus(update);
            isFirstLocate=false;
        }
        MyLocationData.Builder locationBuilder=new MyLocationData.Builder();
        locationBuilder.latitude(location.getLatitude());
        locationBuilder.longitude(location.getLongitude());
        MyLocationData locationData=locationBuilder.build();
        baiduMap.setMyLocationData(locationData);
    }
    public class MyLocationListener implements BDLocationListener{
        @Override
        public void onReceiveLocation(BDLocation location){

            if (location.getLocType()==BDLocation.TypeGpsLocation
                    ||location.getLocType()==BDLocation.TypeNetWorkLocation){
                navigateTo(location);
            }
        }
    }
}

上述程序是最终的程序，在最初的程序运行中出现了如下问题：网络

一、界面空白，只显示网格app

缘由一是没能成功调用百度api，缘由在于申请百度地图key时的包名与建立项目的包名不一致。在建立项目时，填入的包名是com.example.lbstest，然而在打开project时个人包名变成了lbstest.example.com.lbstest，致使api没法导入。缘由二是建立的项目名与包名必须与你在百度地图key上申请的一致，后来又从新申请了一个key，以后便显示出了地图。另外我觉得建立项目时填入的Company Domain就是包名，从而形成错误的产生，其实Company Domain表示公司域名，并非所谓包名称，包名在公司域名的下面。ide

二、没法定位到本身的位置，只显示默认地点布局

在mLocationClient.start();后加mLocationClient.requestLocation();发起定位。ui

三、定位不许确，偏差大this

从上图中看出偏差较大，实际位置为一教，却偏移了几千米。解决方法：要用百度地图的定位坐标，不然是有误差的。在BDLocation location 获取坐标系的时候，在代码LocationClientOption option = new LocationClientOption();后加上option.setCoorType(“bd09ll”);进行坐标转换，不加的话option类型默认gcj02，会产生偏移，须要注意的是bd09ll的l是L的小写，不是数字1。

最终结果：