基本地图应用程序导致classNotFoundException

Question

我正在尝试构建一个只显示地图的非常简单的Google地图应用程序。当项目构建正常时，它会强制关闭模拟器。代码：

helloMaps.java：

package com.example.hellomaps;

import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.view.Menu;

import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.SupportMapFragment;

public class helloMaps extends FragmentActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
       super.onCreate(savedInstanceState);
       setContentView(R.layout.activity_hello_maps);
       GoogleMap map = ((SupportMapFragment)  getSupportFragmentManager().findFragmentById(R.id.map)).getMap();
       map.setMyLocationEnabled(true);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.activity_hello_maps, menu);
        return true;
    }
}

helloMaps.manifest：

    <manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.hellomaps"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="11"
        android:targetSdkVersion="15" />

    <permission
        android:name="com.example.hellomaps.permission.MAPS_RECEIVE"
        android:protectionLevel="signature" />

    <uses-permission android:name="com.example.hellomaps.permission.MAPS_RECEIVE"/>
    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-permission android:name="com.google.android.providers.gsf.permission.READ_GSERVICES" />
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />

    <uses-feature
        android:glEsVersion="0x00020000"
        android:required="true"/>

    <application
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >

        <uses-library android:name="com.google.android.maps"/>

        <activity
            android:name=".helloMaps"
            android:label="@string/title_activity_hello_maps" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <meta-data 
            android:name="com.google.android.maps.v2.API_KEY"
            android:value="api key here"
            />
    </application>

</manifest>

activity_hello_maps.xml：

  <?xml version="1.0" encoding="utf-8"?>
<fragment xmlns:android="http://schemas.android.com/apk/res/android"
 android:id="@+id/map"
 android:layout_width="fill_parent"
 android:layout_height="fill_parent"
 class="com.google.android.gms.maps.SupportMapFragment"/>

启动应用程序会导致classNotFoundException。 logCat输出为：

05-11 10:43:09.614: D/AndroidRuntime(336): Shutting down VM
05-11 10:43:09.614: W/dalvikvm(336): threadid=3: thread exiting with uncaught exception (group=0x4001b188)
05-11 10:43:09.614: E/AndroidRuntime(336): Uncaught handler: thread main exiting due to uncaught exception
05-11 10:43:09.624: E/AndroidRuntime(336): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.hellomaps/com.example.hellomaps.helloMaps}: android.view.InflateException: Binary XML file line #2: Error inflating class fragment
05-11 10:43:09.624: E/AndroidRuntime(336):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2496)
05-11 10:43:09.624: E/AndroidRuntime(336):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2512)
05-11 10:43:09.624: E/AndroidRuntime(336):  at android.app.ActivityThread.access$2200(ActivityThread.java:119)
05-11 10:43:09.624: E/AndroidRuntime(336):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1863)
05-11 10:43:09.624: E/AndroidRuntime(336):  at android.os.Handler.dispatchMessage(Handler.java:99)
05-11 10:43:09.624: E/AndroidRuntime(336):  at android.os.Looper.loop(Looper.java:123)
05-11 10:43:09.624: E/AndroidRuntime(336):  at android.app.ActivityThread.main(ActivityThread.java:4363)
05-11 10:43:09.624: E/AndroidRuntime(336):  at java.lang.reflect.Method.invokeNative(Native Method)
05-11 10:43:09.624: E/AndroidRuntime(336):  at java.lang.reflect.Method.invoke(Method.java:521)
05-11 10:43:09.624: E/AndroidRuntime(336):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:860)
05-11 10:43:09.624: E/AndroidRuntime(336):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)
05-11 10:43:09.624: E/AndroidRuntime(336):  at dalvik.system.NativeStart.main(Native Method)
05-11 10:43:09.624: E/AndroidRuntime(336): Caused by: android.view.InflateException: Binary XML file line #2: Error inflating class fragment
05-11 10:43:09.624: E/AndroidRuntime(336):  at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:582)
05-11 10:43:09.624: E/AndroidRuntime(336):  at android.view.LayoutInflater.inflate(LayoutInflater.java:385)
05-11 10:43:09.624: E/AndroidRuntime(336):  at android.view.LayoutInflater.inflate(LayoutInflater.java:320)
05-11 10:43:09.624: E/AndroidRuntime(336):  at android.view.LayoutInflater.inflate(LayoutInflater.java:276)
05-11 10:43:09.624: E/AndroidRuntime(336):  at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:198)
05-11 10:43:09.624: E/AndroidRuntime(336):  at android.app.Activity.setContentView(Activity.java:1622)
05-11 10:43:09.624: E/AndroidRuntime(336):  at com.example.hellomaps.helloMaps.onCreate(helloMaps.java:12)
05-11 10:43:09.624: E/AndroidRuntime(336):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
05-11 10:43:09.624: E/AndroidRuntime(336):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2459)
05-11 10:43:09.624: E/AndroidRuntime(336):  ... 11 more
05-11 10:43:09.624: E/AndroidRuntime(336): Caused by: java.lang.NullPointerException
05-11 10:43:09.624: E/AndroidRuntime(336):  at java.lang.VMClassLoader.findLoadedClass(Native Method)
05-11 10:43:09.624: E/AndroidRuntime(336):  at java.lang.ClassLoader.findLoadedClass(ClassLoader.java:404)
05-11 10:43:09.624: E/AndroidRuntime(336):  at java.lang.ClassLoader.loadClass(ClassLoader.java:563)
05-11 10:43:09.624: E/AndroidRuntime(336):  at java.lang.ClassLoader.loadClass(ClassLoader.java:532)
05-11 10:43:09.624: E/AndroidRuntime(336):  at android.support.v4.app.Fragment.instantiate(Fragment.java:391)
05-11 10:43:09.624: E/AndroidRuntime(336):  at android.support.v4.app.Fragment.instantiate(Fragment.java:369)
05-11 10:43:09.624: E/AndroidRuntime(336):  at android.support.v4.app.FragmentActivity.onCreateView(FragmentActivity.java:272)
05-11 10:43:09.624: E/AndroidRuntime(336):  at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:558)
05-11 10:43:09.624: E/AndroidRuntime(336):  ... 19 more
05-11 10:43:09.644: I/dalvikvm(336): threadid=7: reacting to signal 3
05-11 10:43:09.644: E/dalvikvm(336): Unable to open stack trace file '/data/anr/traces.txt': Permission denied

我的问题：
1.我如何使这项工作？

Answer 1

将其添加到应用程序元素内的清单中：

<uses-library android:name="com.google.android.maps"/>

例如：

 <application
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name"
    android:theme="@style/AppTheme" >

    <uses-library android:name="com.google.android.maps"/>

    <activity
        android:name=".helloMaps"
        android:label="@string/title_activity_hello_maps" >
        <intent-filter>

Answer 2

你正在使用谷歌地图的API混乱。如果您尝试引用android-support-v4.jar am，假设您正在尝试实施Google Maps API V2。现在，如果是这种情况，那么您的代码中存在很多问题，这些问题很可能导致classNotFoundException错误。

例如，您缺少一些权限：

<permission android:name="your.application.package.permission.MAPS_RECEIVE"  android:protectionLevel="signature"/>
<uses-permission android:name="your.application.package.permission.MAPS_RECEIVE"/>
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="com.google.android.providers.gsf.permission.READ_GSERVICES"/>
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />

接下来，您必须使用MapFragment或SupportMapFragment对象，这些对象是Google Maps API v2对象，而不是您正在使用的MapView对象，即API V1对象。

通过阅读我在此主题上撰写的博客文章，您可以获得有关如何正确实现它的更多信息：

Google Maps API V2

<强>更新

1。首先，如果您定位SupportMapFragment，则无需使用API => 11。

2。删除此权限：

  <uses-library android:name="com.google.android.maps"/>

在 API V2 中不需要 Google Map API V1 权限nad。

3。从你的错误：Error inflating class fragment中膨胀片段存在一些问题。

首先尝试将片段放置在以下布局中：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >

<fragment
    android:name="com.google.android.gms.maps.SupportMapFragment"
    xmlns:map="http://schemas.android.com/apk/res-auto"
    android:id="@+id/map"
    android:layout_width="match_parent"
    android:layout_height="match_parent" />
</LinearLayout>

如果这对您没有帮助，那么在大多数情况下，您在引用Google Map API V2所需的库之前会遇到一些问题，请再次阅读我的指南并确保您正确地执行前4个步骤。