在android中单击按钮显示地图

Question

嘿，伙计们，我想在单击按钮时显示地图...为此，我实现了 2 个类。一个类有一个按钮和一个意图调用，而第二个类显示地图。在运行应用程序时该按钮正在显示，但单击它时应用程序崩溃。 onclick.java

 
public class onclick extends Activity
{
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        Button btnOpen = (Button) findViewById(R.id.btnSave);
        btnOpen.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
               // TODO Auto-generated method stub
               Intent myIntent=new Intent(onclick.this,a.class);
               startActivity(myIntent);

            }
         });
    }
}

a.java

package com.onclick; 
public class a extends MapActivity{
   private MapView mapView;

@Override
   protected boolean isRouteDisplayed() {
      // TODO Auto-generated method stub
      return false;
   }
   @Override
   public void onCreate(Bundle savedInstanceState) {
   super.onCreate(savedInstanceState);
   setContentView(R.layout.f);
   mapView = (MapView)findViewById(R.id.map_view);
   mapView.setStreetView(true);
   }
   }

在 AndroidManifest.xml 中我提供了互联网权限，还使用了 com.google.android.maps 和声明<activity android:name=".a"></activity>

各位请帮帮我...任何帮助将不胜感激

我的 logcat 错误 03-06 16:22:41.812：错误/AndroidRuntime(219)：未捕获的处理程序：线程主因未捕获的异常而退出

03-06 16:22:41.883: 错误/AndroidRuntime(219): java.lang.NoClassDefFoundError: com.onclick.a

03-06 16:22:41.883: 错误/AndroidRuntime(219):at com.onclick.onclick$1.onClick(onclick.java:22)

03-06 16:22:41.883: 错误/AndroidRuntime(219):at android.view.View.performClick(View.java:2364)

03-06 16:22:41.883: 错误/AndroidRuntime(219) 在 android.view.View.onTouchEvent(View.java:4179) 03-06 16:22:41.883: 错误/AndroidRuntime(219): 在 android.widget.TextView.onTouchEvent(TextView.java:6540)

03-06 16:22:41.883: 错误/AndroidRuntime(219): 在 android.view.View.dispatchTouchEvent(View.java:3709)

03-06 16:22:41.883: 错误/AndroidRuntime(219):at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:884)

03-06 16:22:41.883: 错误/AndroidRuntime(219): 在 android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:884)

03-06 16:22:41.883: 错误/AndroidRuntime(219):at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:884)

03-06 16:22:41.883: 错误/AndroidRuntime(219):at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:884)

03-06 16:22:41.883: ERROR/AndroidRuntime(219):at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:1659)

03-06 16:22:41.883: ERROR/AndroidRuntime(219):at com.android.internal.policy.impl.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1107)

03-06 16:22:41.883: 错误/AndroidRuntime(219):at android.app.Activity.dispatchTouchEvent(Activity.java:2061)

03-06 16:22:41.883: ERROR/AndroidRuntime(219):at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:1643)

03-06 16:22:41.883: 错误/AndroidRuntime(219): 在 android.view.ViewRoot.handleMessage(ViewRoot.java:1691)

03-06 16:22:41.883: 错误/AndroidRuntime(219): 在 android.os.Handler.dispatchMessage(Handler.java:99)

03-06 16:22:41.883: 错误/AndroidRuntime(219): 在 android.os.Looper.loop(Looper.java:123)

03-06 16:22:41.883: 错误/AndroidRuntime(219): 在 android.app.ActivityThread.main(ActivityThread.java:4363)

03-06 16:22:41.883: ERROR/AndroidRuntime(219): at java.lang.reflect.Method.invokeNative(Native Method)

03-06 16:22:41.883: 错误/AndroidRuntime(219):at java.lang.reflect.Method.invoke(Method.java:521)

03-06 16:22:41.883: ERROR/AndroidRuntime(219): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:860)

03-06 16:22:41.883: ERROR/AndroidRuntime(219):at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)

03-06 16:22:41.883: ERROR/AndroidRuntime(219):at dalvik.system.NativeStart.main(Native Method)

Answer 1

确保清单和所有 java 文件中的包名称正确