Fragment

最新推荐文章于 2024-06-25 10:30:00 发布

原创最新推荐文章于 2024-06-25 10:30:00 发布 · 277 阅读

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本文介绍了一个Fragment的生命周期管理方法，包括如何通过实例化获取参数、创建视图、设置监听器等。此外，还提供了一个LazyFragment基类，用于实现Fragment的懒加载功能。

  public static BlankFragment getInstance(String argument) {
        Bundle bundle = new Bundle();
        bundle.putString("extra", argument);
        if (blankFragment == null) {
            blankFragment = new BlankFragment();
            blankFragment.setArguments(bundle);
        }
        return blankFragment;
    }

 @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        Log.d(TAG,"onCreateView");
        Bundle bundle = getArguments();
        if (bundle != null) {
            String extra = bundle.getString("extra");
        }
        return inflater.inflate(R.layout.fragment_blank, container, false);
    }

 @Override
    public void onAttach(Context context) {
        super.onAttach(context);
        try {
            mListener = (OnFragmentSelectedListener) getActivity();
        } catch (ClassCastException e) {
            throw new ClassCastException("activity must implement OnFragmentSelectedListener");
        }
        Log.d(TAG, "onAttach");
    }

public abstract class LazyFragment extends Fragment {

    private boolean isVisible;
    private boolean isViewCreated;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View view = inflater.inflate(getLayoutID(), container, false);
        Log.e("blink","onCreateView");
        isViewCreated = true;
        return view;
    }


    @Override
    public void setUserVisibleHint(boolean isVisibleToUser) {
        super.setUserVisibleHint(isVisibleToUser);
        if(getUserVisibleHint()) {
            isVisible = true;
            loadForData();
        } else {
            isVisible = false;
            onInvisible();
        }
        if (isViewCreated && isVisible)
            loadForUI();
    }

    protected abstract void onInvisible();

    protected abstract void loadForData();

    protected abstract void loadForUI();

    // provide layout id
    public abstract int getLayoutID();

}

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