Android 在片段活动中实现toast时出错
以下是片段活动:Android 在片段活动中实现toast时出错,android,android-fragments,Android,Android Fragments,以下是片段活动: public class in_room_dining extends Fragment { Button btnord; @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { View v = inflater.inflate(R.layout.activity_in_room_dining,
public class in_room_dining extends Fragment {
Button btnord;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.activity_in_room_dining, container, false);
Button btnord = (Button) v.findViewById(R.id.ssched);
btnord.setOnClickListener(new View.OnClickListener()
{
@Override
public void onClick(View v) {
Toast.makeText(getActivity(), "Please long press the key", Toast.LENGTH_LONG).show();
}
});
return inflater.inflate(R.layout.activity_in_room_dining, container,false);
}
}
当我运行此操作时,会出现以下错误:
11-29 15:19:53.913
894-894/com.appt.shreyabisht.staymax E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: com.appt.shreyabisht.staymax, PID: 894
java.lang.NullPointerException
at com.appt.shreyabisht.staymax.in_room_dining.onCreateView(in_room_dining.java:24)
at android.support.v4.app.Fragment.performCreateView(Fragment.java:1504)
java:24是btnord.setOnClickListener(newview.OnClickListener())您的
btnord
可能为空,因此当您在其上调用SetOnClickListener
时,会出现异常。您的XML布局活动在餐厅中可能不包含Sched按钮。请检查您的布局也尽量不要像当前一样命名类变量和方法变量。这就是错误所在。但是r、 当我按下按钮时,没有生成吐司。