不幸的是应用程序停止了android模拟器genymotion
我是Android应用程序开发的新手（从昨天起我才开始学习android）。
我在AVD中收到消息 – 不幸的是已经停止了，请帮我解决这个错误，我想在android中学到更多但是被这个错误所吸引.. plz..plz ..帮助我来制作这个。
我的main.java是
package com.example.first; public class MainActivity extends Activity { int counter = 0 ; Button add,sub; TextView total; public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); add = (Button) findViewById(R.id.bt_add); sub = (Button) findViewById(R.id.bt_sub); total = (TextView) findViewById(R.id.textView1); add.setOnClickListener(new View.OnClickListener() { public void onClick(View v) { counter++; total.setText("ur total is "+ counter); } }); } @Override public boolean onCreateOptionsMenu(Menu menu) { // Inflate the menu; this adds items to the action bar if it is present. getMenuInflater().inflate(R.menu.main, menu); return true; } @Override public boolean onOptionsItemSelected(MenuItem item) { // Handle action bar item clicks here. The action bar will // automatically handle clicks on the Home/Up button, so long // as you specify a parent activity in AndroidManifest.xml. int id = item.getItemId(); if (id == R.id.action_settings) { return true; } return super.onOptionsItemSelected(item); } /** * A placeholder fragment containing a simple view. */ public static class PlaceholderFragment extends Fragment { public PlaceholderFragment() { } @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { View rootView = inflater.inflate(R.layout.fragment_main, container, false); return rootView; } } }
我的main.xml是
而日志是
03-29 21:33:13.494: D/AndroidRuntime(1256): Shutting down VM 03-29 21:33:13.494: W/dalvikvm(1256): threadid=1: thread exiting with uncaught exception (group=0xa4d6cb20) 03-29 21:33:13.494: E/AndroidRuntime(1256): FATAL EXCEPTION: main 03-29 21:33:13.494: E/AndroidRuntime(1256): Process: com.example.first, PID: 1256 03-29 21:33:13.494: E/AndroidRuntime(1256): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.first/com.example.first.MainActivity}: java.lang.NullPointerException 03-29 21:33:13.494: E/AndroidRuntime(1256): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195) 03-29 21:33:13.494: E/AndroidRuntime(1256): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245) 03-29 21:33:13.494: E/AndroidRuntime(1256): at android.app.ActivityThread.access$800(ActivityThread.java:135) 03-29 21:33:13.494: E/AndroidRuntime(1256): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196) 03-29 21:33:13.494: E/AndroidRuntime(1256): at android.os.Handler.dispatchMessage(Handler.java:102) 03-29 21:33:13.494: E/AndroidRuntime(1256): at android.os.Looper.loop(Looper.java:136) 03-29 21:33:13.494: E/AndroidRuntime(1256): at android.app.ActivityThread.main(ActivityThread.java:5017) 03-29 21:33:13.494: E/AndroidRuntime(1256): at java.lang.reflect.Method.invokeNative(Native Method) 03-29 21:33:13.494: E/AndroidRuntime(1256): at java.lang.reflect.Method.invoke(Method.java:515) 03-29 21:33:13.494: E/AndroidRuntime(1256): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779) 03-29 21:33:13.494: E/AndroidRuntime(1256): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595) 03-29 21:33:13.494: E/AndroidRuntime(1256): at dalvik.system.NativeStart.main(Native Method) 03-29 21:33:13.494: E/AndroidRuntime(1256): Caused by: java.lang.NullPointerException 03-29 21:33:13.494: E/AndroidRuntime(1256): at com.example.first.MainActivity.onCreate(MainActivity.java:39) 03-29 21:33:13.494: E/AndroidRuntime(1256): at android.app.Activity.performCreate(Activity.java:5231) 03-29 21:33:13.494: E/AndroidRuntime(1256): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087) 03-29 21:33:13.494: E/AndroidRuntime(1256): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159) 03-29 21:33:13.494: E/AndroidRuntime(1256): ... 11 more 03-29 21:34:01.629: D/dalvikvm(1310): Late-enabling CheckJNI 03-29 21:34:01.673: D/AndroidRuntime(1310): Shutting down VM 03-29 21:34:01.673: W/dalvikvm(1310): threadid=1: thread exiting with uncaught exception (group=0xa4d6cb20) 03-29 21:34:01.673: E/AndroidRuntime(1310): FATAL EXCEPTION: main 03-29 21:34:01.673: E/AndroidRuntime(1310): Process: com.example.first, PID: 1310 03-29 21:34:01.673: E/AndroidRuntime(1310): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.first/com.example.first.MainActivity}: java.lang.NullPointerException 03-29 21:34:01.673: E/AndroidRuntime(1310): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195) 03-29 21:34:01.673: E/AndroidRuntime(1310): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245) 03-29 21:34:01.673: E/AndroidRuntime(1310): at android.app.ActivityThread.access$800(ActivityThread.java:135) 03-29 21:34:01.673: E/AndroidRuntime(1310): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196) 03-29 21:34:01.673: E/AndroidRuntime(1310): at android.os.Handler.dispatchMessage(Handler.java:102) 03-29 21:34:01.673: E/AndroidRuntime(1310): at android.os.Looper.loop(Looper.java:136) 03-29 21:34:01.673: E/AndroidRuntime(1310): at android.app.ActivityThread.main(ActivityThread.java:5017) 03-29 21:34:01.673: E/AndroidRuntime(1310): at java.lang.reflect.Method.invokeNative(Native Method) 03-29 21:34:01.673: E/AndroidRuntime(1310): at java.lang.reflect.Method.invoke(Method.java:515) 03-29 21:34:01.673: E/AndroidRuntime(1310): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779) 03-29 21:34:01.673: E/AndroidRuntime(1310): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595) 03-29 21:34:01.673: E/AndroidRuntime(1310): at dalvik.system.NativeStart.main(Native Method) 03-29 21:34:01.673: E/AndroidRuntime(1310): Caused by: java.lang.NullPointerException 03-29 21:34:01.673: E/AndroidRuntime(1310): at com.example.first.MainActivity.onCreate(MainActivity.java:38) 03-29 21:34:01.673: E/AndroidRuntime(1310): at android.app.Activity.performCreate(Activity.java:5231) 03-29 21:34:01.673: E/AndroidRuntime(1310): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087) 03-29 21:34:01.673: E/AndroidRuntime(1310): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159) 03-29 21:34:01.673: E/AndroidRuntime(1310): ... 11 more 03-29 21:36:56.615: D/AndroidRuntime(1358): Shutting down VM 03-29 21:36:56.615: W/dalvikvm(1358): threadid=1: thread exiting with uncaught exception (group=0xa4d6cb20) 03-29 21:36:56.615: E/AndroidRuntime(1358): FATAL EXCEPTION: main 03-29 21:36:56.615: E/AndroidRuntime(1358): Process: com.example.first, PID: 1358 03-29 21:36:56.615: E/AndroidRuntime(1358): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.first/com.example.first.MainActivity}: java.lang.NullPointerException 03-29 21:36:56.615: E/AndroidRuntime(1358): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195) 03-29 21:36:56.615: E/AndroidRuntime(1358): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245) 03-29 21:36:56.615: E/AndroidRuntime(1358): at android.app.ActivityThread.access$800(ActivityThread.java:135) 03-29 21:36:56.615: E/AndroidRuntime(1358): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196) 03-29 21:36:56.615: E/AndroidRuntime(1358): at android.os.Handler.dispatchMessage(Handler.java:102) 03-29 21:36:56.615: E/AndroidRuntime(1358): at android.os.Looper.loop(Looper.java:136) 03-29 21:36:56.615: E/AndroidRuntime(1358): at android.app.ActivityThread.main(ActivityThread.java:5017) 03-29 21:36:56.615: E/AndroidRuntime(1358): at java.lang.reflect.Method.invokeNative(Native Method) 03-29 21:36:56.615: E/AndroidRuntime(1358): at java.lang.reflect.Method.invoke(Method.java:515) 03-29 21:36:56.615: E/AndroidRuntime(1358): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779) 03-29 21:36:56.615: E/AndroidRuntime(1358): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595) 03-29 21:36:56.615: E/AndroidRuntime(1358): at dalvik.system.NativeStart.main(Native Method) 03-29 21:36:56.615: E/AndroidRuntime(1358): Caused by: java.lang.NullPointerException 03-29 21:36:56.615: E/AndroidRuntime(1358): at com.example.first.MainActivity.onCreate(MainActivity.java:38) 03-29 21:36:56.615: E/AndroidRuntime(1358): at android.app.Activity.performCreate(Activity.java:5231) 03-29 21:36:56.615: E/AndroidRuntime(1358): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087) 03-29 21:36:56.615: E/AndroidRuntime(1358): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159) 03-29 21:36:56.615: E/AndroidRuntime(1358): ... 11 more 03-29 21:48:16.663: D/AndroidRuntime(1395): Shutting down VM 03-29 21:48:16.663: W/dalvikvm(1395): threadid=1: thread exiting with uncaught exception (group=0xa4d6cb20) 03-29 21:48:16.663: E/AndroidRuntime(1395): FATAL EXCEPTION: main 03-29 21:48:16.663: E/AndroidRuntime(1395): Process: com.example.first, PID: 1395 03-29 21:48:16.663: E/AndroidRuntime(1395): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.first/com.example.first.MainActivity}: java.lang.NullPointerException 03-29 21:48:16.663: E/AndroidRuntime(1395): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195) 03-29 21:48:16.663: E/AndroidRuntime(1395): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245) 03-29 21:48:16.663: E/AndroidRuntime(1395): at android.app.ActivityThread.access$800(ActivityThread.java:135) 03-29 21:48:16.663: E/AndroidRuntime(1395): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196) 03-29 21:48:16.663: E/AndroidRuntime(1395): at android.os.Handler.dispatchMessage(Handler.java:102) 03-29 21:48:16.663: E/AndroidRuntime(1395): at android.os.Looper.loop(Looper.java:136) 03-29 21:48:16.663: E/AndroidRuntime(1395): at android.app.ActivityThread.main(ActivityThread.java:5017) 03-29 21:48:16.663: E/AndroidRuntime(1395): at java.lang.reflect.Method.invokeNative(Native Method) 03-29 21:48:16.663: E/AndroidRuntime(1395): at java.lang.reflect.Method.invoke(Method.java:515) 03-29 21:48:16.663: E/AndroidRuntime(1395): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779) 03-29 21:48:16.663: E/AndroidRuntime(1395): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595) 03-29 21:48:16.663: E/AndroidRuntime(1395): at dalvik.system.NativeStart.main(Native Method) 03-29 21:48:16.663: E/AndroidRuntime(1395): Caused by: java.lang.NullPointerException 03-29 21:48:16.663: E/AndroidRuntime(1395): at com.example.first.MainActivity.onCreate(MainActivity.java:38) 03-29 21:48:16.663: E/AndroidRuntime(1395): at android.app.Activity.performCreate(Activity.java:5231) 03-29 21:48:16.663: E/AndroidRuntime(1395): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087) 03-29 21:48:16.663: E/AndroidRuntime(1395): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159) 03-29 21:48:16.663: E/AndroidRuntime(1395): ... 11 more 03-29 22:09:36.395: D/AndroidRuntime(1448): Shutting down VM 03-29 22:09:36.395: W/dalvikvm(1448): threadid=1: thread exiting with uncaught exception (group=0xa4d6cb20) 03-29 22:09:36.395: E/AndroidRuntime(1448): FATAL EXCEPTION: main 03-29 22:09:36.395: E/AndroidRuntime(1448): Process: com.example.first, PID: 1448 03-29 22:09:36.395: E/AndroidRuntime(1448): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.first/com.example.first.MainActivity}: java.lang.NullPointerException 03-29 22:09:36.395: E/AndroidRuntime(1448): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195) 03-29 22:09:36.395: E/AndroidRuntime(1448): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245) 03-29 22:09:36.395: E/AndroidRuntime(1448): at android.app.ActivityThread.access$800(ActivityThread.java:135) 03-29 22:09:36.395: E/AndroidRuntime(1448): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196) 03-29 22:09:36.395: E/AndroidRuntime(1448): at android.os.Handler.dispatchMessage(Handler.java:102) 03-29 22:09:36.395: E/AndroidRuntime(1448): at android.os.Looper.loop(Looper.java:136) 03-29 22:09:36.395: E/AndroidRuntime(1448): at android.app.ActivityThread.main(ActivityThread.java:5017) 03-29 22:09:36.395: E/AndroidRuntime(1448): at java.lang.reflect.Method.invokeNative(Native Method) 03-29 22:09:36.395: E/AndroidRuntime(1448): at java.lang.reflect.Method.invoke(Method.java:515) 03-29 22:09:36.395: E/AndroidRuntime(1448): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779) 03-29 22:09:36.395: E/AndroidRuntime(1448): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595) 03-29 22:09:36.395: E/AndroidRuntime(1448): at dalvik.system.NativeStart.main(Native Method) 03-29 22:09:36.395: E/AndroidRuntime(1448): Caused by: java.lang.NullPointerException 03-29 22:09:36.395: E/AndroidRuntime(1448): at com.example.first.MainActivity.onCreate(MainActivity.java:38) 03-29 22:09:36.395: E/AndroidRuntime(1448): at android.app.Activity.performCreate(Activity.java:5231) 03-29 22:09:36.395: E/AndroidRuntime(1448): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087) 03-29 22:09:36.395: E/AndroidRuntime(1448): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159) 03-29 22:09:36.395: E/AndroidRuntime(1448): ... 11 more
PLZ ..解释为什么我会这样..告诉我解决方案
你在第38行得到的NPE是：
add.setOnClickListener(new View.OnClickListener()
所以add为null，因为你将按钮声明为：
add = (Button) findViewById(R.id.bt_add);
所以bt_add id在activity_main上不存在，我认为你发布的这个xml是fragment_main.xml或其他任何东西。
当你将主要布局定义为activity_main时
setContentView(R.layout.activity_main);
所以你必须在activity_main有以下id
1- bt_add
2- bt_sub
3- textView1
所以你必须有以下代码的activity_main ：
看起来你忘了在清单中声明一个活动。 将其添加到AndroidManifest.xml：
该日志显示您尚未在android manefist.xml文件中注册您的活动。 每个活动必须在android清单文件中注册才能工作。 （引自developers.android.com）
从8/26/14开始，似乎有更简单的方法来解决这个问题（如果我错了，请纠正我）但你要做的就是在main.java中更改setContentView（R.layout.activity_main）; to setContentView（R.layout.fragment_main）; 只有更新的原因我有同样的问题ty。