如何通过 Kotlin 在 Android 上以编程方式获取当前 GPS 位置？

本示例介绍如何通过 Kotlin 在 Android 上以编程方式获取当前 GPS 位置。

步骤 1 − 在 Android Studio 中创建新项目，转到 File ⇒ New Project 填写所有必需的详细信息以创建新项目。

步骤 2 − 将以下代码添加到 res/layout/activity_main.xml。

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
   xmlns:tools="http://schemas.android.com/tools"
   android:layout_width="match_parent"
   android:layout_height="match_parent"
   android:padding="4dp"
   tools:context=".MainActivity">
   <TextView
      android:id="@+id/text"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_centerHorizontal="true"
      android:layout_marginTop="70dp"
      android:background="#008080"
      android:padding="5dp"
      android:text="TutorialsPoint"
      android:textColor="#fff"
      android:textSize="24sp"
      android:textStyle="bold" />
   <TextView
      android:id="@+id/textView"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_centerInParent="true"
      android:text="Current GPS Location"
      android:textColor="@color/colorPrimary"
      android:textSize="24sp"
      android:textStyle="bold" />
<Button
   android:id="@+id/getLocation"
   android:layout_width="wrap_content"
   android:layout_height="wrap_content"
   android:layout_below="@+id/text"
   android:layout_centerInParent="true"
   android:layout_marginTop="40dp"
   android:text="Get location" />
</RelativeLayout>

步骤 3 − 将以下代码添加到 src/MainActivity.kt

import android.Manifest
import android.content.Context
import android.content.pm.PackageManager
import android.location.Location
import android.location.LocationListener
import android.location.LocationManager
import android.os.Bundle
import android.widget.Button
import android.widget.TextView
import android.widget.Toast
import androidx.appcompat.app.AppCompatActivity
import androidx.core.app.ActivityCompat
import androidx.core.content.ContextCompat
class MainActivity : AppCompatActivity(), LocationListener {
   private lateinit var locationManager: LocationManager
   private lateinit var tvGpsLocation: TextView
   private val locationPermissionCode = 2
   override fun onCreate(savedInstanceState: Bundle?) {
      super.onCreate(savedInstanceState)
      setContentView(R.layout.activity_main)
      title = "KotlinApp"
      val button: Button = findViewById(R.id.getLocation)
      button.setOnClickListener {
         getLocation()
      }
   }
   private fun getLocation() {
      locationManager = getSystemService(Context.LOCATION_SERVICE) as LocationManager
      if ((ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED)) {
         ActivityCompat.requestPermissions(this, arrayOf(Manifest.permission.ACCESS_FINE_LOCATION), locationPermissionCode)
      }
      locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 5000, 5f, this)
   }
   override fun onLocationChanged(location: Location) {
      tvGpsLocation = findViewById(R.id.textView)
      tvGpsLocation.text = "Latitude: " + location.latitude + " , Longitude: " + location.longitude
   }
   override fun onRequestPermissionsResult(requestCode: Int, permissions: Array<out String>, grantResults: IntArray) {
      if (requestCode == locationPermissionCode) {
         if (grantResults.isNotEmpty() && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
            Toast.makeText(this, "Permission Granted", Toast.LENGTH_SHORT).show()
         }
         else {
            Toast.makeText(this, "Permission Denied", Toast.LENGTH_SHORT).show()
         }
      }
   }
}

步骤 4 − 将以下代码添加到 androidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.example.q11">
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
   <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">
      <activity android:name=".MainActivity">
         <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
         </intent-filter>
      </activity>
   </application>
</manifest>