所以我正在使用 fragment 并尝试连接它们上的点击监听器。
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View contentView = inflater.inflate(R.layout.layout1, null);
// View contentView=super.onCreateView(inflater,null,savedInstanceState,R.layout.layout1);
startButton= (Button) getView().findViewById(R.id.button);
这是按钮的 XML
<Button
android:layout_width="100dp"
android:layout_height="wrap_content"
android:text="Start Time"
android:id="@+id/button"
android:layout_alignParentLeft="true"
android:layout_marginLeft="28dp"
android:layout_marginTop="10dp"
android:background="#1e497c"
android:textColor="#ffffff"/>
这是我的异常(exception)
02-28 16:49:57.162 14375-14375/com.example.listviewandroid E/AndroidRuntime:致命
EXCEPTION: main
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.listviewandroid/com.example.listviewandroid.MainActivity}: java.lang.NullPointerException
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2245)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2295)
at android.app.ActivityThread.access$700(ActivityThread.java:150)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1280)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:175)
at android.app.ActivityThread.main(ActivityThread.java:5279)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1102)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:869)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.NullPointerException
at com.example.fragment.Fragment1.onCreateView(Fragment1.java:43)
at android.support.v4.app.Fragment.performCreateView(Fragment.java:1478)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:927)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1104)
at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:682)
at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1460)
at android.support.v4.app.FragmentActivity.onStart(FragmentActivity.java:556)
at android.app.Instrumentation.callActivityOnStart(Instrumentation.java:1181)
at android.app.Activity.performStart(Activity.java:5293)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2218)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2295)
at android.app.ActivityThread.access$700(ActivityThread.java:150)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1280)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:175)
at android.app.ActivityThread.main(ActivityThread.java:5279)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1102)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:869)
at dalvik.system.NativeStart.main(Native Method)
很明显,它无法找到按钮或发生了一些我无法弄清楚的事情。非常感谢任何帮助。
最佳答案
只需在您的 onCreateView
中使用它
View contentView = inflater.inflate(R.layout.layout1, container, false);
startButton= (Button) contentView.findViewById(R.id.button);
return contentView;