android - 无法转换为com.google.android.gms.common.api.GoogleApiClient $ ConnectionCallback

我正试着像这本手册中那样做，但出了点问题。
致命异常：main

java.lang.RuntimeException: Unable to start activity ComponentInfo{tk.i7otep9wka.testgeo/tk.i7otep9wka.testgeo.MainActivity}: java.lang.ClassCastException: tk.i7otep9wka.testgeo.MainActivity cannot be cast to com.google.android.gms.common.api.GoogleApiClient$ConnectionCallbacks

主要活动

package tk.i7otep9wka.testgeo;

import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;


import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.GooglePlayServicesClient;
import com.google.android.gms.common.api.GoogleApiClient;
import com.google.android.gms.location.LocationServices;


public class MainActivity extends ActionBarActivity implements
        GooglePlayServicesClient.ConnectionCallbacks,
        GooglePlayServicesClient.OnConnectionFailedListener {

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


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }
    protected synchronized void buildGoogleApiClient() {
            GoogleApiClient mGoogleApiClient = new GoogleApiClient.Builder(this)
                .addConnectionCallbacks((GoogleApiClient.ConnectionCallbacks) this)
                .addOnConnectionFailedListener((GoogleApiClient.OnConnectionFailedListener) this)
                .addApi(LocationServices.API)
                .build();
    }

    @Override
    public void onConnected(Bundle bundle) {

    }

    @Override
    public void onDisconnected() {

    }

    @Override
    public void onConnectionFailed(ConnectionResult connectionResult) {

    }
}

显示：

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="tk.i7otep9wka.testgeo" >

    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <meta-data android:name="com.google.android.gms.version"
            android:value="@integer/google_play_services_version" />
        <activity
            android:name=".MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

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

</manifest>

全输出

01-23 02:38:52.230  14704-14704/tk.i7otep9wka.testgeo E/AndroidRuntime﹕ FATAL EXCEPTION: main
    java.lang.RuntimeException: Unable to start activity ComponentInfo{tk.i7otep9wka.testgeo/tk.i7otep9wka.testgeo.MainActivity}: java.lang.ClassCastException: tk.i7otep9wka.testgeo.MainActivity cannot be cast to com.google.android.gms.common.api.GoogleApiClient$ConnectionCallbacks
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2342)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2417)
            at android.app.ActivityThread.access$600(ActivityThread.java:148)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1355)
            at android.os.Handler.dispatchMessage(Handler.java:99)
            at android.os.Looper.loop(Looper.java:150)
            at android.app.ActivityThread.main(ActivityThread.java:5390)
            at java.lang.reflect.Method.invokeNative(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:525)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
            at dalvik.system.NativeStart.main(Native Method)
     Caused by: java.lang.ClassCastException: tk.i7otep9wka.testgeo.MainActivity cannot be cast to com.google.android.gms.common.api.GoogleApiClient$ConnectionCallbacks
            at tk.i7otep9wka.testgeo.MainActivity.buildGoogleApiClient(MainActivity.java:49)
            at tk.i7otep9wka.testgeo.MainActivity.onCreate(MainActivity.java:23)
            at android.app.Activity.performCreate(Activity.java:5303)
            at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2296)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2417)
            at android.app.ActivityThread.access$600(ActivityThread.java:148)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1355)
            at android.os.Handler.dispatchMessage(Handler.java:99)
            at android.os.Looper.loop(Looper.java:150)
            at android.app.ActivityThread.main(ActivityThread.java:5390)
            at java.lang.reflect.Method.invokeNative(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:525)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
            at dalvik.system.NativeStart.main(Native Method)

最佳答案

public class MainActivity extends ActionBarActivity implements
    GoogleApiClient.ConnectionCallbacks,
    GoogleApiClient.OnConnectionFailedListener {}

 protected synchronized void buildGoogleApiClient() {
        GoogleApiClient mGoogleApiClient = new GoogleApiClient.Builder(this)
            .addConnectionCallbacks(this)
            .addOnConnectionFailedListener(this)
            .addApi(LocationServices.API)
            .build();
}

关于android - 无法转换为com.google.android.gms.common.api.GoogleApiClient $ ConnectionCallback，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/28101330/