Android 封裝Fragment-BaseLazyFragment（懶加載）

Fragment 封裝

1.封裝佈局(比較簡單)

一般寫Fragment繼承android.support.v4.app.Fragment 重寫Fragment的生命週期實現創建過程：添加布局

 @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View v = null;
        if (v == null) {
            v = inflater.inflate(R.layout.common_booklist_fragment, container, false);
            ButterKnife.bind(this, v);
            emptyLayout = new EmptyLayout(getActivity(), listview);
        }
        return v;
        }

BaseLazyFragment.java

  @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        int layoutId = getContentViewLayoutID();
        if (layoutId != 0) {
            return inflater.inflate(layoutId, container, false);
        } else {
            return super.onCreateView(inflater, container, savedInstanceState);
        }
    }

protected abstract int getContentViewLayoutID();//獲取佈局xml

使用的話很簡單繼承BaseLazyFragment重寫getContentViewLayoutID()就行。

2.初始化控件 或者事件總線

@Override
    public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);
        ButterKnife.bind(this, view);
        initViewsAndEvents(view);
    }

  protected abstract void initViewsAndEvents(View view);//初始化控件，如果使用butterknife就不需要寫findViewById；

3.懶加載

第一次可見狀態、可見狀態、第一次不可見狀態、不可見狀態

    private boolean isFirstVisible = true;
    private boolean isFirstInvisible = true;
    private boolean isPrepared;

    @Override
    public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        initPrepare();
    }

    private synchronized void initPrepare() {
        if (isPrepared) {
            onFirstUserVisible();
        } else {
            isPrepared = true;
        }
    }

    @Override
    public void setUserVisibleHint(boolean isVisibleToUser) {
        super.setUserVisibleHint(isVisibleToUser);
        if (isVisibleToUser) {
            if (isFirstVisible) {
                isFirstVisible = false;
                initPrepare();
            } else {
                onUserVisible();
            }
        } else {
            if (isFirstInvisible) {
                isFirstInvisible = false;
                onFirstUserInvisible();
            } else {
                onUserInvisible();
            }
        }
    }

    protected abstract void onFirstUserVisible();
    protected abstract void onUserVisible();
    private void onFirstUserInvisible() { }
    protected abstract void onUserInvisible();

4.跳轉

 /**
     * 封裝跳轉
     */
    protected void readyGo(Class<?> clazz) {
        Intent intent = new Intent(getActivity(), clazz);
        startActivity(intent);
    }

    protected void readyGo(Class<?> clazz, Bundle bundle) {
        Intent intent = new Intent(getActivity(), clazz);
        if (null != bundle) {
            intent.putExtras(bundle);
        }
        startActivity(intent);
    }

    protected void readyGoForResult(Class<?> clazz, int requestCode) {
        Intent intent = new Intent(getActivity(), clazz);
        startActivityForResult(intent, requestCode);
    }

    protected void readyGoForResult(Class<?> clazz, int requestCode, Bundle bundle) {
        Intent intent = new Intent(getActivity(), clazz);
        if (null != bundle) {
            intent.putExtras(bundle);
        }
        startActivityForResult(intent, requestCode);
    }

5.添加Toast，Dialog等等

源碼：

/**
 * Created by ziyang on 16/12/28.
 * Version 1.0
 * 封裝Fragment懶加載
 * <p>
 * onCreateView() xml
 * onViewCreated() butterKnife initView()
 */

public abstract class BaseLazyFragment extends Fragment {

    private boolean isPrepared;
    private boolean isFirstVisible = true;
    private boolean isFirstInvisible = true;

    private Dialog mPro;
    protected MyToast myToast;
    protected Handler mHandler = new Handler() {
        @Override
        public void handleMessage(Message msg) {
            if (msg.what == DIALOG_SHOW) {
                mPro.show();
            } else {
                mPro.dismiss();
            }

        }
    };

    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        int layoutId = getContentViewLayoutID();
        if (layoutId != 0) {
            return inflater.inflate(layoutId, container, false);
        } else {
            return super.onCreateView(inflater, container, savedInstanceState);
        }
    }

    @Override
    public void onActivityCreated(@Nullable Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        initPrepare();

        mPro = createLoadingDialog1(getActivity());
        myToast = new MyToast(getActivity());
    }

    private synchronized void initPrepare() {
        if (isPrepared) {
            onFirstUserVisible();
        } else {
            isPrepared = true;
        }
    }


    @Override
    public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);
        ButterKnife.bind(this, view);
        initViewsAndEvents(view);
    }

    @Override
    public void setUserVisibleHint(boolean isVisibleToUser) {
        super.setUserVisibleHint(isVisibleToUser);
        if (isVisibleToUser) {
            if (isFirstVisible) {
                isFirstVisible = false;
                initPrepare();
            } else {
                onUserVisible();
            }
        } else {
            if (isFirstInvisible) {
                isFirstInvisible = false;
                onFirstUserInvisible();
            } else {
                onUserInvisible();
            }
        }
    }

    @Override
    public void onDestroy() {
        super.onDestroy();

        destroyViewAndThing();
    }

    protected abstract void onFirstUserVisible();//加載數據，開啓動畫/廣播..

    protected abstract void onUserVisible();///開啓動畫/廣播..

    private void onFirstUserInvisible() {
    }

    protected abstract void onUserInvisible();//暫停動畫，暫停廣播

    protected abstract int getContentViewLayoutID();

    protected abstract void initViewsAndEvents(View view);

    protected abstract void destroyViewAndThing();//銷燬動作

    public Dialog createLoadingDialog1(Context context) {
        LayoutInflater inflater = LayoutInflater.from(context);
        View v = inflater.inflate(R.layout.loading_dialog, null);        // 得到加載view
        RelativeLayout layout = (RelativeLayout) v.findViewById(R.id.rl_probar);  // 加載佈局
        Dialog loadingDialog = new Dialog(context, R.style.loading_dialog); // 創建自定義樣式dialog
        layout.setVisibility(View.VISIBLE);
        loadingDialog.setCancelable(true);// 不可以用"返回鍵"取消
        loadingDialog.setCanceledOnTouchOutside(true);
        loadingDialog.setContentView(layout, new LinearLayout.LayoutParams(LinearLayout.LayoutParams.WRAP_CONTENT,
                LinearLayout.LayoutParams.WRAP_CONTENT));
        return loadingDialog;
    }

    /**
     * 封裝跳轉
     */
    protected void readyGo(Class<?> clazz) {
        Intent intent = new Intent(getActivity(), clazz);
        startActivity(intent);
    }

    protected void readyGo(Class<?> clazz, Bundle bundle) {
        Intent intent = new Intent(getActivity(), clazz);
        if (null != bundle) {
            intent.putExtras(bundle);
        }
        startActivity(intent);
    }

    protected void readyGoForResult(Class<?> clazz, int requestCode) {
        Intent intent = new Intent(getActivity(), clazz);
        startActivityForResult(intent, requestCode);
    }

    protected void readyGoForResult(Class<?> clazz, int requestCode, Bundle bundle) {
        Intent intent = new Intent(getActivity(), clazz);
        if (null != bundle) {
            intent.putExtras(bundle);
        }
        startActivityForResult(intent, requestCode);
    }

}

當然還有MVP的封裝：

public abstract class BaseFragment<T extends BasePresenter> extends SupportFragment {

    private final String TAG = getClass().getSimpleName();
    protected T mPresenter;
    protected Context mContext;
    protected View rootView;
    protected Unbinder unbinder;
    private boolean isViewPrepared; // 標識fragment視圖已經初始化完畢
    private boolean hasFetchData; // 標識已經觸發過懶加載數據

    @Override
    public void onAttach(Context mContext) {
        super.onAttach(mContext);
        KL.d(this.getClass(), getName() + "------>onAttach");
        if (mContext != null) {
            this.mContext = mContext;
        } else {
            this.mContext = getActivity();
        }
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        KL.d(this.getClass(), getName() + "------>onCreate");
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        KL.d(this.getClass(), getName() + "------>onCreateView");
        if (rootView == null) {
            rootView = inflater.inflate(getLayout(), container, false);
        }
        ViewGroup parent = (ViewGroup) rootView.getParent();
        if (parent != null) {
            parent.removeView(rootView);
        }
        unbinder = ButterKnife.bind(this, rootView);
        initView(inflater);
        EventBus.getDefault().register(this);
        setTitleHeight(rootView);
        return rootView;
    }

    @Override
    public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        KL.d(this.getClass(), getName() + "------>onActivityCreated");
        initEvent();
    }

    @Override
    public void onStart() {
        super.onStart();
        KL.d(this.getClass(), getName() + "------>onStart");
    }

    @Override
    public void onResume() {
        super.onResume();
        KL.d(this.getClass(), getName() + "------>onResume");
    }

    @Override
    public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);
        KL.d(this.getClass(), getName() + "------>onViewCreated");
        isViewPrepared = true;
        lazyFetchDataIfPrepared();
    }

    @Override
    public void onPause() {
        super.onPause();
        KL.d(this.getClass(), getName() + "------>onPause");
    }

    @Override
    public void onStop() {
        super.onStop();
        KL.d(this.getClass(), getName() + "------>onStop");
    }

    @Override
    public void onDestroyView() {
        EventBus.getDefault().unregister(this);
        super.onDestroyView();
        KL.d(this.getClass(), getName() + "------>onDestroyView");
        // view被銷燬後，將可以重新觸發數據懶加載，因爲在viewpager下，fragment不會再次新建並走onCreate的生命週期流程，將從onCreateView開始
        hasFetchData = false;
        isViewPrepared = false;
        mPresenter = null;
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        KL.d(this.getClass(), getName() + "------>onDestroy");
        if (unbinder != null)
            unbinder.unbind();
    }

    @Override
    public void onDetach() {
        super.onDetach();
        KL.d(this.getClass(), getName() + "------>onDetach");
    }

    @Override
    public void setUserVisibleHint(boolean isVisibleToUser) {
        super.setUserVisibleHint(isVisibleToUser);
        Log.v(TAG, getClass().getName() + "------>isVisibleToUser = " + isVisibleToUser);
        if (isVisibleToUser) {
            lazyFetchDataIfPrepared();
        }
    }

    private void lazyFetchDataIfPrepared() {
        // 用戶可見fragment && 沒有加載過數據 && 視圖已經準備完畢
        if (getUserVisibleHint() && !hasFetchData && isViewPrepared) {
            hasFetchData = true;
            lazyFetchData();
        }

    }

    /**
     * 懶加載的方式獲取數據，僅在滿足fragment可見和視圖已經準備好的時候調用一次
     */
    protected void lazyFetchData() {
        Log.v(TAG, getClass().getName() + "------>lazyFetchData");
    }

    public String getName() {
        return BaseFragment.class.getName();
    }

    protected abstract int getLayout();

    protected void initView(LayoutInflater inflater) {
    }

    protected void initEvent() {
    }
}

參考鏈接：Android談談封裝那些事–BaseActivity和BaseFragment(二)

封裝篇——Fragment懶加載