android - 当我添加谷歌分析时，发生classcastException

Question

现在，我在我的应用程序中添加了Google Analytics（分析）。

我已经完成了Google Analytics（分析）首页的所有操作。
（https://developers.google.com/analytics/devguides/collection/android/v4/#manifest）

但是在我在MainActivity中添加Tracker代码后，运行我的应用程序时会发生ClassCastException。

请给我一个答案。

我已经在搜索谷歌和堆栈溢出。

后面是我的代码。

ApplicationTrackers.java

package com.zla.android;

import java.util.HashMap;
import android.app.Application;
import com.google.android.gms.analytics.GoogleAnalytics;
import com.google.android.gms.analytics.Tracker;
import com.zla.android.R;

public class ApplicationTrackers extends Application {

	private static final String PROPERTY_ID = "UA-XXXXXXXX-2";

	public enum TrackerName {
		APP_TRACKER, // Tracker used only in this app.
		GLOBAL_TRACKER, // Tracker used by all the apps from a company. eg: roll-up tracking.
		ECOMMERCE_TRACKER, // Tracker used by all ecommerce transactions from a company.
	}
	HashMap<TrackerName, Tracker> mTrackers = new HashMap<TrackerName, Tracker>();
	
	synchronized Tracker getTracker(TrackerName trackerId) {
		if (!mTrackers.containsKey(trackerId)) {			
			GoogleAnalytics analytics = GoogleAnalytics.getInstance(this);
			Tracker t = (trackerId == TrackerName.APP_TRACKER) ? analytics.newTracker(PROPERTY_ID)
					: (trackerId == TrackerName.GLOBAL_TRACKER) ? analytics.newTracker(R.xml.global_tracker)
					: analytics.newTracker(R.xml.ecommerce_tracker);
			mTrackers.put(trackerId, t);					
		}
		return mTrackers.get(trackerId);
	}
}

global_tracker.xml

<?xml version="1.0" encoding="utf-8"?>
<resources xmlns:tools="http://schemas.android.com/tools"
tools:ignore="TypographyDashes">
	
	<integer name="ga_sessionTimeout">300</integer>

    <!-- Enable automatic Activity measurement -->
    <bool name="ga_autoActivityTracking">true</bool>

    <!-- The screen names that will appear in reports -->
    <screenName name="com.zla.android.MainActivity">
        MainActivity
    </screenName>
    
    <string name="ga_trackingId">UA-XXXXXXXX-2</string>
</resources>

ecommerce_tracker.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
	<integer name="ga_sessionTimeout">300</integer>
	<string name="ga_trackingId">UA-XXXXXXXX-2</string>    
</resources>

MainActivity.java

package com.zla.android;

import com.google.android.gms.analytics.HitBuilders;
import com.google.android.gms.analytics.Tracker;
import android.app.ActionBar;
import android.app.Activity;
import android.content.Intent;
import android.database.Cursor;
import android.graphics.Color;
import android.os.Bundle;
import android.view.Gravity;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.TextView;
import android.widget.ToggleButton;

public class MainActivity extends Activity {
	
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		
		
		/* add google analytics --------------------------------------------- */
		Tracker t = ((ApplicationTrackers)getApplication()).getTracker(ApplicationTrackers.TrackerName.APP_TRACKER);
		t.setScreenName("MainActivity");
		t.send(new HitBuilders.AppViewBuilder().build());
		/* ------------------------------------------------------------------ */

androidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.zla.android"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="16"
        android:targetSdkVersion="21" />
    
    <!-- about google analytics -->
	<uses-permission android:name="android.permission.INTERNET" />
	<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
		
    <application
        android:allowBackup="true"
        android:icon="@drawable/app_icon"
        android:label="@string/app_name"
        android:theme="@style/AppTheme"
        android:largeHeap="true"  >

        <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>
        
        <activity
            android:name="com.zla.android.SearchBrandActivity"
            android:label="search page" />
        
        <activity
            android:name="com.zla.android.SearchFrameActivity"
            android:label="search page" />
        
        <activity
            android:name="com.zla.android.ListActivity"
            android:label="list page"
            android:parentActivityName="com.zla.android.MainActivity" >
        </activity>
        
        <activity
            android:name="com.zla.android.ListActivity_WishList"
            android:label="list page"
            android:parentActivityName="com.zla.android.MainActivity" >
        </activity>
        
        <activity
            android:name="com.zla.android.DetailActivity"
            android:label="detail page"
            android:parentActivityName="com.zla.android.ListActivity" />
        
        <!-- about google analytics -->
        <meta-data
			android:name="com.google.android.gms.version"
			android:value="@integer/google_play_services_version" />
                
        <activity
            android:name="com.zla.android.ApplicationTrackers"
            android:label="google analytics" />
        
    </application>

</manifest>

错误的LogCat

04-05 03:27:42.498: E/AndroidRuntime(22322): FATAL EXCEPTION: main
04-05 03:27:42.498: E/AndroidRuntime(22322): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.zla.android/com.zla.android.MainActivity}: java.lang.ClassCastException: android.app.Application cannot be cast to com.zla.android.ApplicationTrackers
04-05 03:27:42.498: E/AndroidRuntime(22322): 	at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2110)
04-05 03:27:42.498: E/AndroidRuntime(22322): 	at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2135)
04-05 03:27:42.498: E/AndroidRuntime(22322): 	at android.app.ActivityThread.access$700(ActivityThread.java:143)
04-05 03:27:42.498: E/AndroidRuntime(22322): 	at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1241)
04-05 03:27:42.498: E/AndroidRuntime(22322): 	at android.os.Handler.dispatchMessage(Handler.java:99)
04-05 03:27:42.498: E/AndroidRuntime(22322): 	at android.os.Looper.loop(Looper.java:137)
04-05 03:27:42.498: E/AndroidRuntime(22322): 	at android.app.ActivityThread.main(ActivityThread.java:4950)
04-05 03:27:42.498: E/AndroidRuntime(22322): 	at java.lang.reflect.Method.invokeNative(Native Method)
04-05 03:27:42.498: E/AndroidRuntime(22322): 	at java.lang.reflect.Method.invoke(Method.java:511)
04-05 03:27:42.498: E/AndroidRuntime(22322): 	at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:997)
04-05 03:27:42.498: E/AndroidRuntime(22322): 	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:764)
04-05 03:27:42.498: E/AndroidRuntime(22322): 	at dalvik.system.NativeStart.main(Native Method)
04-05 03:27:42.498: E/AndroidRuntime(22322): Caused by: java.lang.ClassCastException: android.app.Application cannot be cast to com.zla.android.ApplicationTrackers
04-05 03:27:42.498: E/AndroidRuntime(22322): 	at com.zla.android.MainActivity.onCreate(MainActivity.java:67)
04-05 03:27:42.498: E/AndroidRuntime(22322): 	at android.app.Activity.performCreate(Activity.java:5177)
04-05 03:27:42.498: E/AndroidRuntime(22322): 	at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1094)
04-05 03:27:42.498: E/AndroidRuntime(22322): 	at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2074)
04-05 03:27:42.498: E/AndroidRuntime(22322): 	... 11 more

Answer 1

您没有将com.zla.android.ApplicationTrackers用作应用程序实现。您需要在类名称扩展为android.app.Application的AndroidManifest.xml中的application元素中添加"name"属性。

<application
    ...
    android:name="com.zla.android.ApplicationTrackers">
    ...

没有name属性，Android无法知道哪个类实现了该应用程序，并将实例化默认的 android.app.Application。当您以后尝试将其强制转换为自定义应用程序类时，由于尝试将 android.app.Application强制转换为 com.zla.android.ApplicationTrackers，因此转换失败。