片段在开始使用Oncheckedchanged时引起NPE

Question

i具有动态显示片段的活动。默认片段的开关，如果启用了，则可以启动服务。

但是，每当我切换开关时，都会获得NullPoInterException。errorlog在这里

我该怎么做才能解决这个问题？我应该将按钮的代码扔到主要活动而不是片段上吗？这不是问题，但我真的很想把它放在片段中。

我的片段：

public class DefaultScreen extends Fragment {
SharedPreferences.Editor edit_status;
private SharedPreferences service_status;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    /** Inflating the layout for this fragment **/
    View v = inflater.inflate(R.layout.fragment_default, null);
    Switch sEnable = (Switch) v.findViewById(R.id.switch_service);
    Switch sRoot = (Switch) v.findViewById(R.id.switch_root);
    sEnable.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
        @Override
        public void onCheckedChanged(CompoundButton compoundButton, boolean isChecked) {
            Toast.makeText(getActivity(), "Service Switch State = " +isChecked, Toast.LENGTH_SHORT).show();
            Context ctx = (Context)DefaultScreen.this.getActivity();
            if(isChecked)
            {
            edit_status.putBoolean("ServiceMode", true).commit();
            ctx.startService(new Intent(getActivity(), SensorService.class));
            } else {
                edit_status.putBoolean("ServiceMode", false).commit();
                ctx.stopService(new Intent(getActivity(), SensorService.class));
            }
        }
    });
    sRoot.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
        @Override
        public void onCheckedChanged(CompoundButton compoundButton, boolean isChecked) {
            Toast.makeText(getActivity(), "Root Switch State = " +isChecked, Toast.LENGTH_SHORT).show();
        }
    });
    return v;
}
private boolean proximityService(Context context) {
    @SuppressWarnings("rawtypes")
    Iterator iterator = ((ActivityManager) context.getSystemService("activity")).getRunningServices(Integer.MAX_VALUE).iterator();

    while (iterator.hasNext()) {
        ActivityManager.RunningServiceInfo runningServiceInfo = (ActivityManager.RunningServiceInfo) iterator
                .next();
        if (SensorService.class.getName().equals(
                runningServiceInfo.service.getClassName())) {
            return true;
        }
    }
    return false;
}

}

Answer 1

未初始化您的： edit_status

在使用它之前：

edit_status.putBoolean("ServiceMode", true).commit();