android - why is Switch Compat causing null pointer in fragment when calling onCheckedChange

Question

rather explanatory title here is the xml

        <android.support.v7.widget.SwitchCompat
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/mySwitch"
        app:showText="false"
        android:textOn="On"
        android:textOff="Off"
        android:layout_marginLeft="@dimen/activity_horizontal_margin"
        android:layout_marginRight="@dimen/activity_horizontal_margin" />

and here is the main of what im doing in my fragment

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    View rootView = inflater.inflate(R.layout.intro_frag, container, false);
    getPrefs = PreferenceManager.getDefaultSharedPreferences(getActivity());
    switchCompat = (SwitchCompat) getActivity().findViewById(R.id.mySwitch);

    return rootView;

}

@Override
public void onActivityCreated(final Bundle savedInstanceState) {
    super.onActivityCreated(savedInstanceState);
    switchCompat.setOnCheckedChangeListener(new   
    CompoundButton.OnCheckedChangeListener() {
        @Override
        public void onCheckedChanged(CompoundButton buttonView, boolean 
        isChecked) {
            if (isChecked) {
               //do stuff
            }
            else if (!isChecked){
               //do other stuff
            }
        }
    });

the line switchCompat.setOnCheckedChangeListener is causing a null pointer exception without it everything runs fine ive searched the issue and found a few fixes like the switch needing text and stuff but i cannot get this working can anybody help?

Answer 1

你的错误是：

getActivity()

改成：

switchCompat = (SwitchCompat) rootView.findViewById(R.id.mySwitch);