我需要帮助！ ：）
我已经创建了一个差不多完成的应用程序，我已经在许多设备和许多Android版本上进行了测试。在Android L和KitKat上一切正常，但是当我尝试在Gingerbread上打开它时，它将无法启动。
这是我的主要活动：
public class MainActivity extends FragmentActivity {
private GoogleMap googleMap;
LocationManager locationManager;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final LocationManager manager = (LocationManager)getSystemService(Context.LOCATION_SERVICE );
if ( !manager.isProviderEnabled( LocationManager.GPS_PROVIDER ) ) {
showGPSDisabledAlertToUser();
} else {
setUpMapIfNeeded();
}
TextView txView = (TextView)findViewById(R.id.calculate);
... ECC
那是日志猫：
09-28 09:53:01.320: E/AndroidRuntime(2766): FATAL EXCEPTION: main
09-28 09:53:01.320: E/AndroidRuntime(2766): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.lifeapps.speedcalc/com.lifeapps.speedcalc.MainActivity}: android.view.InflateException: Binary XML file line #78: Error inflating class fragment
09-28 09:53:01.320: E/AndroidRuntime(2766): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1651)
09-28 09:53:01.320: E/AndroidRuntime(2766): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1667)
09-28 09:53:01.320: E/AndroidRuntime(2766): at android.app.ActivityThread.access$1500(ActivityThread.java:117)
09-28 09:53:01.320: E/AndroidRuntime(2766): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:935)
09-28 09:53:01.320: E/AndroidRuntime(2766): at android.os.Handler.dispatchMessage(Handler.java:99)
09-28 09:53:01.320: E/AndroidRuntime(2766): at android.os.Looper.loop(Looper.java:130)
09-28 09:53:01.320: E/AndroidRuntime(2766): at android.app.ActivityThread.main(ActivityThread.java:3687)
09-28 09:53:01.320: E/AndroidRuntime(2766): at java.lang.reflect.Method.invokeNative(Native Method)
09-28 09:53:01.320: E/AndroidRuntime(2766): at java.lang.reflect.Method.invoke(Method.java:507)
09-28 09:53:01.320: E/AndroidRuntime(2766): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:842)
09-28 09:53:01.320: E/AndroidRuntime(2766): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:600)
09-28 09:53:01.320: E/AndroidRuntime(2766): at dalvik.system.NativeStart.main(Native Method)
09-28 09:53:01.320: E/AndroidRuntime(2766): Caused by: android.view.InflateException: Binary XML file line #78: Error inflating class fragment
09-28 09:53:01.320: E/AndroidRuntime(2766): at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:581)
09-28 09:53:01.320: E/AndroidRuntime(2766): at android.view.LayoutInflater.rInflate(LayoutInflater.java:623)
09-28 09:53:01.320: E/AndroidRuntime(2766): at android.view.LayoutInflater.rInflate(LayoutInflater.java:626)
09-28 09:53:01.320: E/AndroidRuntime(2766): at android.view.LayoutInflater.inflate(LayoutInflater.java:408)
09-28 09:53:01.320: E/AndroidRuntime(2766): at android.view.LayoutInflater.inflate(LayoutInflater.java:320)
09-28 09:53:01.320: E/AndroidRuntime(2766): at android.view.LayoutInflater.inflate(LayoutInflater.java:276)
09-28 09:53:01.320: E/AndroidRuntime(2766): at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:209)
09-28 09:53:01.320: E/AndroidRuntime(2766): at android.app.Activity.setContentView(Activity.java:1657)
09-28 09:53:01.320: E/AndroidRuntime(2766): at com.lifeapps.speedcalc.MainActivity.onCreate(MainActivity.java:38)
09-28 09:53:01.320: E/AndroidRuntime(2766): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
09-28 09:53:01.320: E/AndroidRuntime(2766): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1615)
09-28 09:53:01.320: E/AndroidRuntime(2766): ... 11 more
09-28 09:53:01.320: E/AndroidRuntime(2766): Caused by: java.lang.ClassNotFoundException: android.view.fragment in loader dalvik.system.PathClassLoader[/data/app/com.lifeapps.speedcalc-1.apk]
09-28 09:53:01.320: E/AndroidRuntime(2766): at dalvik.system.PathClassLoader.findClass(PathClassLoader.java:240)
09-28 09:53:01.320: E/AndroidRuntime(2766): at java.lang.ClassLoader.loadClass(ClassLoader.java:551)
09-28 09:53:01.320: E/AndroidRuntime(2766): at java.lang.ClassLoader.loadClass(ClassLoader.java:511)
09-28 09:53:01.320: E/AndroidRuntime(2766): at android.view.LayoutInflater.createView(LayoutInflater.java:471)
09-28 09:53:01.320: E/AndroidRuntime(2766): at android.view.LayoutInflater.onCreateView(LayoutInflater.java:549)
09-28 09:53:01.320: E/AndroidRuntime(2766): at com.android.internal.policy.impl.PhoneLayoutInflater.onCreateView(PhoneLayoutInflater.java:66)
09-28 09:53:01.320: E/AndroidRuntime(2766): at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:568)
09-28 09:53:01.320: E/AndroidRuntime(2766): ... 21 more
问题在于：
setContentView(R.layout.activity_main);
但我不知道为什么。关于如何解决我的问题的任何想法？
P.S。 Android Manifest设置为minsdkversion：10。