Question

我做了两项活动，主要活动和GPS活动。

我在主要活动中使用意图定向到GPS活动，但每当我按下按钮时，它会一直重定向回主要活动。我不知道为什么。

我尝试了其他活动的意图并且成功了。此外，GPS活动单独工作。有人可以帮忙吗？

我试图创建一个新项目，但它也没有成功并且它没有显示任何错误或例外。

我正在使用min SDK 21。

主要活动：

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    Button two = (Button) findViewById(R.id.button2);
    two.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            Intent Intent = new Intent(MainActivity.this,Gps.class);

            startActivity( Intent);
        }
    });
}

GPS活动：

import android.content.Intent;
import android.content.pm.PackageManager;
import android.location.Location;
import android.support.v4.app.ActivityCompat;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.TextView;
import android.widget.Toast;

import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.api.GoogleApiClient.*;
import com.google.android.gms.common.api.GoogleApiClient;
import com.google.android.gms.location.LocationServices;
import com.google.android.gms.location.LocationRequest;
import com.google.android.gms.location.LocationListener;

public class Gps extends AppCompatActivity implements ConnectionCallbacks, OnConnectionFailedListener, LocationListener {
    TextView x;
    TextView y;
    LocationRequest LR;
    private GoogleApiClient GAC;
    //public  String lat="Latitude";
    //public  String lon="Longitude";

    @Override
    public void onConnected(Bundle connectionHint) {
        createLocationRequest();
        startLocationUpdates();
        if (ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
            return;
        }
        Location Location = LocationServices.FusedLocationApi.getLastLocation(GAC);
        if (Location != null) {
            Double Lat = Location.getLatitude();
            Double lon = Location.getLongitude();
            x = (TextView) findViewById(R.id.textView);
            y = (TextView) findViewById(R.id.textView2);
            x.setText("Ltitude is " + String.valueOf(Lat));
            y.setText("Longitude is " + String.valueOf(lon));
        }


    }


    @Override
    protected void onStart() {
        super.onStart();
        if (GAC != null) {
            GAC.connect();
        }
    }

    @Override

    protected void onStop() {
        GAC.disconnect();
        super.onStop();
    }

    @Override
    public void onConnectionSuspended(int cause) {
        Toast.makeText(this, "the connection suspended", Toast.LENGTH_LONG).show();
    }

    @Override
    public void onConnectionFailed(ConnectionResult result) {

        Toast.makeText(this, "the connection failed", Toast.LENGTH_LONG).show();

    }

    @Override
    public void onLocationChanged(Location location) {
        x = (TextView) findViewById(R.id.textView);
        y = (TextView) findViewById(R.id.textView2);
        x.setText("latitude is " + String.valueOf(location.getLatitude()));
        y.setText("longitude is " + String.valueOf(location.getLongitude()));
    }

    protected void createLocationRequest() {
        LR = new LocationRequest();
        LR.setInterval(5000);
        LR.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
    }

    protected void startLocationUpdates() {

        if (ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {

            return;
        }
        LocationServices.FusedLocationApi.requestLocationUpdates(
                GAC, LR, (this));

    }



    protected void build_GAC(){
        GAC =new GoogleApiClient.Builder(this)
                .addApi(LocationServices.API)
                .addConnectionCallbacks(this)
                .addOnConnectionFailedListener(this)
                .build();

    }



    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        build_GAC();


    }
}

app.gradle：

apply plugin: 'com.android.application'

android {
    compileSdkVersion 24
    buildToolsVersion "24.0.3"
    defaultConfig {
        applicationId "com.example.toshiba.intent"
        minSdkVersion 21
        targetSdkVersion 24
        versionCode 1
        versionName "1.0"
        multiDexEnabled  true
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    compile fileTree(include: ['*.jar'], dir: 'libs')
    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:10.2.1'
    compile 'com.android.support:multidex:1.0.0'

}

Answer 1

 @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        build_GAC();


    }

您在R.layout.activity_main中使用了主要活动的布局（Gps Activity），因此活动正在发生变化，但您无法看到差异。

意图重定向到同一个活动

1 个答案: