无法解析 Android 上的 MapActivity 类

我有一个包含 11 种不同活动的应用程序。这些活动之一是 MapActivity 的扩展（它是用于数据可视化的地图）。要进入此活动，用户必须首先完成启动活动，然后完成其他 3 个活动。启动MapActivity的代码是：

Intent i = new Intent(getBaseContext(), MapVis.class);
i.putExtra("edu.uml.cs.isense.visualizations.session_list", sessions);
startActivity(i);

执行此操作后，我从日志中得到以下输出：

09-01 14:36:22.389: WARN/dalvikvm(592): Class resolved by unexpected DEX: Ledu/uml/cs/isense/visualizations/MapVis;(0x44981910):0x128260 ref [Lcom/google/android/maps/MapActivity;] Lcom/google/android/maps/MapActivity;(0x44981910):0x13d330
09-01 14:36:22.389: WARN/dalvikvm(592): (Ledu/uml/cs/isense/visualizations/MapVis; had used a different Lcom/google/android/maps/MapActivity; during pre-verification)
09-01 14:36:22.389: WARN/dalvikvm(592): Unable to resolve superclass of Ledu/uml/cs/isense/visualizations/MapVis; (118)
09-01 14:36:22.389: WARN/dalvikvm(592): Link of class 'Ledu/uml/cs/isense/visualizations/MapVis;' failed
09-01 14:36:22.389: DEBUG/AndroidRuntime(592): Shutting down VM
09-01 14:36:22.389: WARN/dalvikvm(592): threadid=1: thread exiting with uncaught exception (group=0x4001d7f0)
09-01 14:36:22.399: ERROR/AndroidRuntime(592): FATAL EXCEPTION: main
09-01 14:36:22.399: ERROR/AndroidRuntime(592): java.lang.NoClassDefFoundError: edu.uml.cs.isense.visualizations.MapVis
09-01 14:36:22.399: ERROR/AndroidRuntime(592):     at edu.uml.cs.isense.visualizations.Visualizations.onOptionsItemSelected(Visualizations.java:213)
09-01 14:36:22.399: ERROR/AndroidRuntime(592):     at android.app.Activity.onMenuItemSelected(Activity.java:2195)
09-01 14:36:22.399: ERROR/AndroidRuntime(592):     at com.android.internal.policy.impl.PhoneWindow.onMenuItemSelected(PhoneWindow.java:730)
09-01 14:36:22.399: ERROR/AndroidRuntime(592):     at com.android.internal.view.menu.MenuItemImpl.invoke(MenuItemImpl.java:143)
09-01 14:36:22.399: ERROR/AndroidRuntime(592):     at com.android.internal.view.menu.MenuBuilder.performItemAction(MenuBuilder.java:855)
09-01 14:36:22.399: ERROR/AndroidRuntime(592):     at com.android.internal.view.menu.IconMenuView.invokeItem(IconMenuView.java:532)
09-01 14:36:22.399: ERROR/AndroidRuntime(592):     at com.android.internal.view.menu.IconMenuItemView.performClick(IconMenuItemView.java:122)
09-01 14:36:22.399: ERROR/AndroidRuntime(592):     at android.view.View$PerformClick.run(View.java:8816)
09-01 14:36:22.399: ERROR/AndroidRuntime(592):     at android.os.Handler.handleCallback(Handler.java:587)
09-01 14:36:22.399: ERROR/AndroidRuntime(592):     at android.os.Handler.dispatchMessage(Handler.java:92)
09-01 14:36:22.399: ERROR/AndroidRuntime(592):     at android.os.Looper.loop(Looper.java:123)
09-01 14:36:22.399: ERROR/AndroidRuntime(592):     at android.app.ActivityThread.main(ActivityThread.java:4627)
09-01 14:36:22.399: ERROR/AndroidRuntime(592):     at java.lang.reflect.Method.invokeNative(Native Method)
09-01 14:36:22.399: ERROR/AndroidRuntime(592):     at java.lang.reflect.Method.invoke(Method.java:521)
09-01 14:36:22.399: ERROR/AndroidRuntime(592):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
09-01 14:36:22.399: ERROR/AndroidRuntime(592):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
09-01 14:36:22.399: ERROR/AndroidRuntime(592):     at dalvik.system.NativeStart.main(Native Method)
09-01 14:36:22.399: ERROR/AndroidRuntime(592): Caused by: java.lang.IllegalAccessError: Class ref in pre-verified class resolved to unexpected implementation
09-01 14:36:22.399: ERROR/AndroidRuntime(592):     at dalvik.system.DexFile.defineClass(Native Method)
09-01 14:36:22.399: ERROR/AndroidRuntime(592):     at dalvik.system.DexFile.loadClassBinaryName(DexFile.java:209)
09-01 14:36:22.399: ERROR/AndroidRuntime(592):     at dalvik.system.PathClassLoader.findClass(PathClassLoader.java:203)
09-01 14:36:22.399: ERROR/AndroidRuntime(592):     at java.lang.ClassLoader.loadClass(ClassLoader.java:573)
09-01 14:36:22.399: ERROR/AndroidRuntime(592):     at java.lang.ClassLoader.loadClass(ClassLoader.java:532)
09-01 14:36:22.399: ERROR/AndroidRuntime(592):     ... 17 more
09-01 14:36:22.409: WARN/ActivityManager(92):   Force finishing activity edu.uml.cs.isense/.visualizations.Visualizations
09-01 14:36:22.909: WARN/ActivityManager(92): Activity pause timeout for HistoryRecord{44c84a90 edu.uml.cs.isense/.visualizations.Visualizations}

我确实将目标设置为 Google API，这是一个适用于 Android 1.5 的应用程序，并在清单文件中将 minsdk 指定为级别 3。地图的使用库也在清单文件中。

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
      package="edu.uml.cs.isense"
      android:versionCode="1"
      android:versionName="1.0">
    <uses-permission android:name="android.permission.WRITE_SETTINGS" />
    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
    <uses-permission android:name="android.permission.CONTROL_LOCATION_UPDATES"/>
    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>
    <uses-permission android:name="android.permission.ACCESS_LOCATION_EXTRA_COMMANDS"/>
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <application android:icon="@drawable/icon" android:label="@string/app_name">
        <activity android:name=".Isense" 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=".experiments.Experiments" android:label="@string/app_name_experiments"/>
  <activity android:name=".sessions.Sessions" android:label="@string/app_name"/>
  <activity android:name=".people.People" android:label="@string/app_name_people"/>
  <activity android:name=".profile.Profile" android:label="@string/app_name"/>
  <activity android:name=".sensors.Sensors" android:label="@string/app_name_sensors"/>
  <activity android:name=".visualizations.DataTable" android:label="@string/app_name"/>
  <activity android:name=".visualizations.Visualizations" android:label="@string/app_name"/>
  <activity android:name=".sensors.DataListActivity"
                  android:label="@string/selectFile"
                  android:theme="@android:style/Theme.Dialog"
                  android:configChanges="orientation|keyboardHidden" />
        <activity android:name=".sensors.Upload" android:label="@string/app_name_uploader"/>
        <activity android:name=".visualizations.MapVis" android:label="@string/app_name"
            android:theme="@android:style/Theme.NoTitleBar" />
        <uses-library android:name="com.google.android.maps"/>
</application>
    <uses-sdk android:minSdkVersion="3"/>
</manifest>

我已经这样做了将近两天，但没有任何结果。似乎很多人在从其他活动启动 MapActivity 时遇到问题，但没有任何解决方案。有人有线索吗？谢谢。

问题是你的MapVis班级可能会延长com.google.android.maps.MapActivity。为了让系统能够找到这个类，你需要做两件事：

首先确保您的项目包含 Androidmaps.jar在你的构建路径中。从Eclipse中找到

Project > Properties > Android

然后选择适合您的应用的“Google API”之一。您可以通过检查以下内容来确认maps.jar位于您的构建路径中：

Project > Properties > Java Build Path > Libraries > Expand "Google Apis"

其次浏览到您的清单文件并确保您拥有uses-library嵌套在<application>标签如下：

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

愿原力与你同在！