버튼에 onClickListener를 호출하고 있습니다. 나는 이것을 여러 번 해봤으며 이전에 효과가있었습니다. 그러나 어쨌든 그것은 이번에 NullPointerException
을 던졌습니다. 여러 게시물을 살펴 보았지만 아직 이해하지 못했습니다.setOnClickListener가 NullPointerException을 throw합니다.
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.search);
Button viewRequests = (Button) findViewById(R.id.view_requests);
viewRequests.setOnClickListener(new View.OnClickListener() { // NPException occurred here
@Override
public void onClick(View v) {
System.out.println("View request is clicked");
}
});
}
리소스 파일 :
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:paddingLeft="20dp"
android:paddingRight="20dp"
android:paddingTop="10dp"
android:paddingBottom="10dp" >
<Button
android:id="@+id/view_requests"
android:background="@drawable/my_button"
android:layout_width="120dp"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:layout_alignParentTop="true"
android:paddingTop="3dp"
android:paddingBottom="3dp"
android:textSize="10sp"
android:text="View Work Requests" />
</RelativeLayout>
편집
로그 캣
07-20 17:26:40.411: D/AndroidRuntime(334): Shutting down VM
07-20 17:26:40.411: W/dalvikvm(334): threadid=1: thread exiting with uncaught exception (group=0x40015560)
07-20 17:26:40.431: E/AndroidRuntime(334): FATAL EXCEPTION: main
07-20 17:26:40.431: E/AndroidRuntime(334): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.rxprojects/com.rxprojects.activities.SearchActivity}: java.lang.NullPointerException
07-20 17:26:40.431: E/AndroidRuntime(334): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1647)
07-20 17:26:40.431: E/AndroidRuntime(334): at android.app.ActivityThread.startActivityNow(ActivityThread.java:1487)
07-20 17:26:40.431: E/AndroidRuntime(334): at android.app.LocalActivityManager.moveToState(LocalActivityManager.java:127)
07-20 17:26:40.431: E/AndroidRuntime(334): at android.app.LocalActivityManager.startActivity(LocalActivityManager.java:339)
07-20 17:26:40.431: E/AndroidRuntime(334): at android.widget.TabHost$IntentContentStrategy.getContentView(TabHost.java:654)
07-20 17:26:40.431: E/AndroidRuntime(334): at android.widget.TabHost.setCurrentTab(TabHost.java:326)
07-20 17:26:40.431: E/AndroidRuntime(334): at android.widget.TabHost$2.onTabSelectionChanged(TabHost.java:132)
07-20 17:26:40.431: E/AndroidRuntime(334): at android.widget.TabWidget$TabClickListener.onClick(TabWidget.java:456)
07-20 17:26:40.431: E/AndroidRuntime(334): at android.view.View.performClick(View.java:2485)
07-20 17:26:40.431: E/AndroidRuntime(334): at android.view.View$PerformClick.run(View.java:9080)
07-20 17:26:40.431: E/AndroidRuntime(334): at android.os.Handler.handleCallback(Handler.java:587)
07-20 17:26:40.431: E/AndroidRuntime(334): at android.os.Handler.dispatchMessage(Handler.java:92)
07-20 17:26:40.431: E/AndroidRuntime(334): at android.os.Looper.loop(Looper.java:123)
07-20 17:26:40.431: E/AndroidRuntime(334): at android.app.ActivityThread.main(ActivityThread.java:3683)
07-20 17:26:40.431: E/AndroidRuntime(334): at java.lang.reflect.Method.invokeNative(Native Method)
07-20 17:26:40.431: E/AndroidRuntime(334): at java.lang.reflect.Method.invoke(Method.java:507)
07-20 17:26:40.431: E/AndroidRuntime(334): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
07-20 17:26:40.431: E/AndroidRuntime(334): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
07-20 17:26:40.431: E/AndroidRuntime(334): at dalvik.system.NativeStart.main(Native Method)
07-20 17:26:40.431: E/AndroidRuntime(334): Caused by: java.lang.NullPointerException
07-20 17:26:40.431: E/AndroidRuntime(334): at com.rxprojects.activities.SearchActivity.onCreate(SearchActivity.java:226)
07-20 17:26:40.431: E/AndroidRuntime(334): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
07-20 17:26:40.431: E/AndroidRuntime(334): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1611)
07-20 17:26:40.431: E/AndroidRuntime(334): ... 18 more
정확한 오류 메시지를 게시 하시겠습니까? – maxko87
클릭 수신기를 제거하면 화면에 표시된 버튼입니까? 또한 단지'search.xml'라고 불렀고'/ res/layout /'폴더에있는 layout xml 파일을 명확히하기 위해서입니까? – FoamyGuy
이상한. 의심스러운 로그가 있습니까? 깨끗이하고 다시 빌드하십시오. –