我正在关注this教程。我试过关注最终失败的youtube视频。 当我注释掉实现locationlistener，locationcallbacks以及为获取位置而运行的所有代码的代码时，该应用程序正常工作。
这是我的清单文件：
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="tc.elicz.roadpal">
<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
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>
这是我的main_activity.java文件：
package tc.elicz.roadpal;
import android.Manifest;
import android.app.Dialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Build;
import android.provider.Settings;
import android.support.annotation.NonNull;
import android.support.v4.app.ActivityCompat;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.Button;
import android.widget.TextView;
import com.google.android.gms.common.api.GoogleApi;
import com.google.android.gms.common.api.GoogleApiClient;
import com.google.android.gms.location.LocationRequest;
import com.google.android.gms.location.LocationServices;
import com.google.android.gms.common.api.GoogleApiClient.ConnectionCallbacks;
import org.xml.sax.helpers.LocatorImpl;
import java.util.Map;
import static com.google.android.gms.location.LocationServices.FusedLocationApi;
public abstract class MainActivity extends AppCompatActivity implements GoogleApiClient.ConnectionCallbacks, GoogleApiClient.OnConnectionFailedListener{
private Button button;
private TextView textView1;
private LocationManager locationManager;
private LocationListener locationListener;
private GoogleApiClient mapo = null;
private Location lastloc = null;
private String lat = null;
private String lon = null;
private LocationRequest locreq= new LocationRequest();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
System.out.println("sosll");
setContentView(R.layout.activity_main);
textView1 = (TextView) findViewById(R.id.textView);
if (mapo == null) {
mapo = new GoogleApiClient.Builder(this)
.addConnectionCallbacks(this)
.addOnConnectionFailedListener(this)
.addApi(LocationServices.API)
.build();
}
}
protected void onStart() {
super.onStart();
mapo.connect();
}
protected void onStop() {
super.onStop();
mapo.disconnect();
}
@Override
public void onConnected(Bundle connectionHint) {
if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
textView1.append("No permission");
System.out.println("No perm");
return;
}
lastloc = LocationServices.FusedLocationApi.getLastLocation(mapo);
if (lastloc != null) {
lat=(String.valueOf(lastloc.getLatitude()));
lon=(String.valueOf(lastloc.getLongitude()));
textView1.append("Lat:" + lat +"lon:" +lon);
}
}
}
我还根据教程对gradle文件进行了一些更改：
apply plugin: 'com.android.application'
android {
compileSdkVersion 24
buildToolsVersion "24.0.3"
defaultConfig {
applicationId "tc.elicz.roadpal"
minSdkVersion 22
targetSdkVersion 24
versionCode 1
versionName "1.0"
testInstrumentationRunner
"android.support.test.runner.AndroidJUnitRunner"
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
}
}
}
dependencies {
compile fileTree(dir: 'libs', include: ['*.jar'])
androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
exclude group: 'com.android.support', module: 'support-annotations'
})
compile 'com.android.support:appcompat-v7:24.2.1'
testCompile 'junit:junit:4.12'
compile 'com.google.android.gms:play-services:11.0.4'
}
这是我的日志文件：
11-05 23:00:41.825 16961-16961/? I/art: Late-enabling -Xcheck:jni
11-05 23:00:41.891 16961-16961/tc.elicz.roadpal W/System:ClassLoader
referenced unknown path: /data/app/tc.elicz.roadpal-1/lib/arm
11-05 23:00:41.906 16961-16961/tc.elicz.roadpal I/InstantRun: Instant Run
Runtime started. Android package is tc.elicz.roadpal, real application class
is null.
11-05 23:00:42.049 16961-16961/tc.elicz.roadpal W/System: ClassLoader
referenced unknown path: /data/app/tc.elicz.roadpal-1/lib/arm
11-05 23:00:42.091 16961-16961/tc.elicz.roadpal I/FirebaseInitProvider:
FirebaseApp initialization unsuccessful
11-05 23:00:42.119 16961-16961/tc.elicz.roadpal D/AndroidRuntime: Shutting
down VM
11-05 23:00:42.119 16961-16961/tc.elicz.roadpal E/AndroidRuntime: FATAL
EXCEPTION: main
Process:
tc.elicz.roadpal, PID: 16961
java.lang.RuntimeException: Unable to instantiate activity
ComponentInfo{tc.elicz.roadpal/tc.elicz.roadpal.MainActivity}:
java.lang.InstantiationException:
java.lang.Class<tc.elicz.roadpal.MainActivity> cannot be instantiated
at
android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2601)
at
android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2766)
at
android.app.ActivityThread.-wrap12(ActivityThread.java)
at
android.app.ActivityThread$H.handleMessage(ActivityThread.java:1507)
at
android.os.Handler.dispatchMessage(Handler.java:102)
at
android.os.Looper.loop(Looper.java:154)
at
android.app.ActivityThread.main(ActivityThread.java:6236)
at
java.lang.reflect.Method.invoke(Native Method)
at
com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run
(ZygoteInit.java:891)
at
com.android.internal.os.ZygoteInit.main(ZygoteInit.java:781)
Caused by:
java.lang.InstantiationException:
java.lang.Class<tc.elicz.roadpal.MainActivity> cannot be instantiated
at
java.lang.Class.newInstance(Native Method)
at
android.app.Instrumentation.newActivity(Instrumentation.java:1079)
at
android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2591)
at
android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2766)
at
android.app.ActivityThread.-wrap12(ActivityThread.java)
at
android.app.ActivityThread$H.handleMessage(ActivityThread.java:1507)
at
android.os.Handler.dispatchMessage(Handler.java:102)
at
android.os.Looper.loop(Looper.java:154)
at
android.app.ActivityThread.main(ActivityThread.java:6236)
at
java.lang.reflect.Method.invoke(Native Method)
at
com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run
(ZygoteInit.java:891)
at
com.android.internal.os.ZygoteInit.main(ZygoteInit.java:781)
答案 0 :(得分：0)
我不能说这会起作用，但过去它对我有用
我认为您需要在主活动类中添加无参数构造函数。
在主要活动中，
MainActivity(){
super();
}
如果这样做有用，请尝试删除该行（仅作为最终手段进行测试）：
private LocationRequest locreq= new LocationRequest();