android cnfException

Question

我正在尝试编写一个在地图上显示当前设备位置的应用程序。当我尝试将其安装到设备上时，它说找不到我的主要活动类。它还说 dalvikvm 无法解析该类的超类，这显然是 MapActivity。有什么想法吗？谢谢。

import java.util.List;

import com.google.android.maps.GeoPoint;
import com.google.android.maps.MapActivity;
import com.google.android.maps.MapController;
import com.google.android.maps.MapView;
import com.google.android.maps.Overlay;

import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Point;
import android.graphics.drawable.Drawable;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.view.KeyEvent;
import android.view.ViewGroup;
import android.view.ViewGroup.LayoutParams;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ZoomControls;

public class WcFinderActivity extends MapActivity implements LocationListener {
    /** Called when the activity is first created. */

    EditText        txted           = null;

    Button          btnSimple       = null;

    MapView         gMapView        = null;

    MapController   mc              = null;

    Drawable        defaultMarker   = null;

    GeoPoint        p               = null;

    double          latitude        = 18.9599990845, longitude = 72.819999694;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        // Creating TextBox displying Lat, Long
        txted = (EditText) findViewById(R.id.id1);
        String currentLocation = "Lat: " + latitude + " Lng: " + longitude;
        txted.setText(currentLocation);

        // Creating and initializing Map
        gMapView = (MapView) findViewById(R.id.myGMap);
        p = new GeoPoint((int) (latitude * 1000000), (int) (longitude * 1000000));
        gMapView.setSatellite(true);
        mc = gMapView.getController();
        mc.setCenter(p);
        mc.setZoom(14);

        // Add a location mark
        MyLocationOverlay myLocationOverlay = new MyLocationOverlay();
        List<Overlay> list = gMapView.getOverlays();
        list.add(myLocationOverlay);

        // Adding zoom controls to Map
        ZoomControls zoomControls = (ZoomControls) gMapView.getZoomControls();
        zoomControls.setLayoutParams(new ViewGroup.LayoutParams(LayoutParams.WRAP_CONTENT,
                LayoutParams.WRAP_CONTENT));

        gMapView.addView(zoomControls);
        gMapView.displayZoomControls(true);

        // Getting locationManager and reflecting changes over map if distance travel by
        // user is greater than 500m from current location.
        LocationManager lm = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
        lm.requestLocationUpdates(LocationManager.GPS_PROVIDER, 1000L, 500.0f, this);
    }

    /* This method is called when use position will get changed */
    public void onLocationChanged(Location location) {
        if (location != null) {
            double lat = location.getLatitude();
            double lng = location.getLongitude();
            String currentLocation = "Lat: " + lat + " Lng: " + lng;
            txted.setText(currentLocation);
            p = new GeoPoint((int) lat * 1000000, (int) lng * 1000000);
            mc.animateTo(p);
        }
    }

    public void onProviderDisabled(String provider) {
        // required for interface, not used
    }

    public void onProviderEnabled(String provider) {
        // required for interface, not used
    }

    public void onStatusChanged(String provider, int status, Bundle extras) {
        // required for interface, not used
    }

    protected boolean isRouteDisplayed() {
        // TODO Auto-generated method stub
        return false;
    }

    /* User can zoom in/out using keys provided on keypad */
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        if (keyCode == KeyEvent.KEYCODE_I) {
            gMapView.getController().setZoom(gMapView.getZoomLevel() + 1);
            return true;
        } else if (keyCode == KeyEvent.KEYCODE_O) {
            gMapView.getController().setZoom(gMapView.getZoomLevel() - 1);
            return true;
        } else if (keyCode == KeyEvent.KEYCODE_S) {
            gMapView.setSatellite(true);
            return true;
        } else if (keyCode == KeyEvent.KEYCODE_T) {
            gMapView.setTraffic(true);
            return true;
        }
        return false;
    }

    /* Class overload draw method which actually plot a marker,text etc. on Map */
    protected class MyLocationOverlay extends com.google.android.maps.Overlay {

        @Override
        public boolean draw(Canvas canvas, MapView mapView, boolean shadow, long when) {
            Paint paint = new Paint();

            super.draw(canvas, mapView, shadow);
            // Converts lat/lng-Point to OUR coordinates on the screen.
            Point myScreenCoords = new Point();
            mapView.getProjection().toPixels(p, myScreenCoords);

            paint.setStrokeWidth(1);
            paint.setARGB(255, 255, 255, 255);
            paint.setStyle(Paint.Style.STROKE);

            Bitmap bmp = BitmapFactory.decodeResource(getResources(), R.drawable.ic_launcher);

            canvas.drawBitmap(bmp, myScreenCoords.x, myScreenCoords.y, paint);
            canvas.drawText("I am here...", myScreenCoords.x, myScreenCoords.y, paint);
            return true;
        }
    }
}

01-18 15:04:07.223：W/dalvikvm(3554)：无法解析 Lcom/tecmark/WcFinderActivity 的超类； (23) 01-18 15:04:07.238: W/dalvikvm(3554): 类“Lcom/tecmark/WcFinderActivity;”的链接失败的 01-18 15:04:07.238：D/AndroidRuntime(3554)：关闭虚拟机 01-18 15:04:07.238: W/dalvikvm(3554): threadid=3: 线程因未捕获的异常而退出 (group=0x4001b180) 01-18 15：04：07.238：E / AndroidRuntime（3554）：未捕获的处理程序：由于未捕获的异常，线程主退出 01-18 15:04:07.278: E/AndroidRuntime(3554): java.lang.RuntimeException: 无法实例化活动 ComponentInfo{com.tecmark/com.tecmark.WcFinderActivity}: java.lang.ClassNotFoundException: com.tecmark.WcFinderActivity在加载器 dalvik.system.PathClassLoader@43e57a18 中 01-18 15：04：07.278：E / AndroidRuntime（3554）：在android.app.ActivityThread.performLaunchActivity（ActivityThread.java：2417） 01-18 15：04：07.278：E / AndroidRuntime（3554）：在android.app.ActivityThread.handleLaunchActivity（ActivityThread.java：2512） 01-18 15:04:07.278: E/AndroidRuntime(3554): 在 android.app.ActivityThread.access$2200(ActivityThread.java:119) 01-18 15:04:07.278: E/AndroidRuntime(3554): 在 android.app.ActivityThread$H.handleMessage(ActivityThread.java:1863) 01-18 15:04:07.278: E/AndroidRuntime(3554): 在 android.os.Handler.dispatchMessage(Handler.java:99) 01-18 15:04:07.278: E/AndroidRuntime(3554): 在 android.os.Looper.loop(Looper.java:123) 01-18 15:04:07.278: E/AndroidRuntime(3554): 在 android.app.ActivityThread.main(ActivityThread.java:4363) 01-18 15：04：07.278：E / AndroidRuntime（3554）：在java.lang.reflect.Method.invokeNative（本机方法） 01-18 15:04:07.278: E/AndroidRuntime(3554): 在 java.lang.reflect.Method.invoke(Method.java:521) 01-18 15:04:07.278: E/AndroidRuntime(3554): 在 com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:860) 01-18 15:04:07.278: E/AndroidRuntime(3554): 在 com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618) 01-18 15：04：07.278：E / AndroidRuntime（3554）：在dalvik.system.NativeStart.main（本机方法） 01-18 15：04：07.278：E / AndroidRuntime（3554）：引起：java.lang.ClassNotFoundException：加载程序dalvik.system.PathClassLoader@43e57a18中的com.tecmark.WcFinderActivity 01-18 15：04：07.278：E / AndroidRuntime（3554）：在dalvik.system.PathClassLoader.findClass（PathClassLoader.java：243） 01-18 15:04:07.278: E/AndroidRuntime(3554): 在 java.lang.ClassLoader.loadClass(ClassLoader.java:573) 01-18 15:04:07.278: E/AndroidRuntime(3554): 在 java.lang.ClassLoader.loadClass(ClassLoader.java:532) 01-18 15:04:07.278: E/AndroidRuntime(3554): 在 android.app.Instrumentation.newActivity(Instrumentation.java:1021) 01-18 15：04：07.278：E / AndroidRuntime（3554）：在android.app.ActivityThread.performLaunchActivity（ActivityThread.java：2409） 01-18 15:04:07.278: E/AndroidRuntime(3554): ... 11 更多

。

<?xml version="1.0" ?>
        <manifest xmlns:android="http://schemas.android.com/apk/res/android"
            package="com.tecmark"
            android:versionCode="1"
            android:versionName="1.0" >

            <uses-sdk android:minSdkVersion="7" />
             <uses-permission android:name="android.permission.INTERNET"></uses-permission>
            <uses-library android:name="com.google.android.maps" />
            <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"></uses-permission>
            <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"></uses-permission>

            <application
                android:icon="@drawable/ic_launcher"
                android:label="@string/app_name" >
                <activity
                    android:name=".WcFinderActivity"
                    android:label="@string/app_name" >
                    <intent-filter>
                        <action android:name="android.intent.action.MAIN" />

                        <category android:name="android.intent.category.LAUNCHER" />
                    </intent-filter>
                </activity>

            </application>



        </manifest>

Answer 1

抱歉我犯了一个愚蠢的错误。我将 use-library 标签移至应用程序标签内，它现在可以编译并安装在手机上。我认为这也解释了超类不能被解析的错误。我的活动扩展了 MapActivity，这可能是在 google api 库中定义的，但未在应用程序标记之间声明。