Android 该应用程序在安卓4.0.3上不起作用，但在安卓2.3.4上起作用

我有一个在Android 2.3.4（仿真器/手机）上完美运行的应用程序。但我试着将它安装在Android 4.0.3（模拟器/手机）上，当我运行它时，它不起作用。它向我显示了这条信息

"Unfortunately AppName has stopped"

当出现错误时，应用程序正在执行以下类：

public class EmpleadosAct extends Activity {

private ArrayList<String> datos;
private ListView list;

public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    ActualizarVehiculos();

}

public void ActualizarVehiculos() {

    try {
        NotesCenter messageCenter = new NotesCenterImpl();

        List<Vehiculo> vehiculo = messageCenter.getVehiculo();

        for (Vehiculo v : vehiculo) {
            AndroidOpenDbHelper androidOpenDbHelperObj = new AndroidOpenDbHelper(
                    this);

            SQLiteDatabase sqliteDatabase = androidOpenDbHelperObj
                    .getWritableDatabase();

            ContentValues contentValues = new ContentValues();
            contentValues.put(AndroidOpenDbHelper.matricula, v.matricula);

            long affectedColumnId = sqliteDatabase.insert("Vehiculos",
                    null, contentValues);
            sqliteDatabase.close();
        }
    } catch (Exception ex) {
        Log.v("blah", ex.getMessage());

    }

}
}

第二个日志：

06-04 21:40:03.225: V/blah(720): Error happened: 
06-04 21:40:03.225: V/blah(720): android.os.NetworkOnMainThreadException
06-04 21:40:03.225: V/blah(720):    at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1099)
06-04 21:40:03.225: V/blah(720):    at libcore.io.BlockGuardOs.connect(BlockGuardOs.java:84)
06-04 21:40:03.225: V/blah(720):    at libcore.io.IoBridge.connectErrno(IoBridge.java:127)
06-04 21:40:03.225: V/blah(720):    at libcore.io.IoBridge.connect(IoBridge.java:112)
06-04 21:40:03.225: V/blah(720):    at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:192)
06-04 21:40:03.225: V/blah(720):    at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:459)
06-04 21:40:03.225: V/blah(720):    at java.net.Socket.connect(Socket.java:842)
06-04 21:40:03.225: V/blah(720):    at org.apache.http.conn.scheme.PlainSocketFactory.connectSocket(PlainSocketFactory.java:119)
06-04 21:40:03.225: V/blah(720):    at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:144)
06-04 21:40:03.225: V/blah(720):    at org.apache.http.impl.conn.AbstractPoolEntry.open(AbstractPoolEntry.java:164)
06-04 21:40:03.225: V/blah(720):    at org.apache.http.impl.conn.AbstractPooledConnAdapter.open(AbstractPooledConnAdapter.java:119 )
06-04 21:40:03.225: V/blah(720):    at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:360)
06-04 21:40:03.225: V/blah(720):    at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:555)
06-04 21:40:03.225: V/blah(720):    at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:487)
06-04 21:40:03.225: V/blah(720):    at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:465)
06-04 21:40:03.225: V/blah(720):    at myapp.net.HttpNote.doGet(HttpNote.java:32)
06-04 21:40:03.225: V/blah(720):    at myapp.net.NotesCenterImpl.getVehiculo(NotesCenterImpl.java:23)
06-04 21:40:03.225: V/blah(720):    at myapp.net.EmpleadosAct.ActualizarVehiculo(EmpleadosAct.java:91)
06-04 21:40:03.225: V/blah(720):    at myapp.net.EmpleadosAct.onCreate(EmpleadosAct.java:24)
06-04 21:40:03.225: V/blah(720):    at android.app.Activity.performCreate(Activity.java:4465)
06-04 21:40:03.225: V/blah(720):    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049)
06-04 21:40:03.225: V/blah(720):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1920)
06-04 21:40:03.225: V/blah(720):    at  android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1981)
06-04 21:40:03.225: V/blah(720):    at android.app.ActivityThread.access$600(ActivityThread.java:123)
06-04 21:40:03.225: V/blah(720):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1147)
06-04 21:40:03.225: V/blah(720):    at android.os.Handler.dispatchMessage(Handler.java:99)
06-04 21:40:03.225: V/blah(720):    at android.os.Looper.loop(Looper.java:137)
06-04 21:40:03.225: V/blah(720):    at android.app.ActivityThread.main(ActivityThread.java:4424)
06-04 21:40:03.225: V/blah(720):    at java.lang.reflect.Method.invokeNative(Native Method)
06-04 21:40:03.225: V/blah(720):    at java.lang.reflect.Method.invoke(Method.java:511)
06-04 21:40:03.225: V/blah(720):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
06-04 21:40:03.225: V/blah(720):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
06-04 21:40:03.225: V/blah(720):    at dalvik.system.NativeStart.main(Native Method)

那么，是什么原因导致android在2.3.4中一切正常，而在4.0.3中一切都不正常？我的代码不支持4.0.3版本，有问题吗

谢谢你的回答或建议

Log.v("blah", ex.getMessage());

问题是

ex.getMessage（）

返回

null

。您可以检查

null

，但更好的方法是将异常作为第三个参数显式传递给log方法：

Log.v("blah", "Error happened: ", ex);

问题是

ex.getMessage（）

返回

null

。您可以检查

null

，但更好的方法是将异常作为第三个参数显式传递给log方法：

Log.v("blah", "Error happened: ", ex);

---

更妙的是，将异常作为根本原因传递：

Log.v（标记为“Error while”\uuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuux）谢谢您的时间。我修改了我的代码并添加了第二个日志。更妙的是，将异常作为根本原因传递：
Log.v（标记“Error while”，ex）谢谢您的时间。我修改了代码并添加了第二个日志。
Log.v("blah", "Error happened: ", ex);