BottomSheetDemo

#a bottomsheet widget that can modify height and drag state
#Code:
public abstract class BaseBottomSheetFrag extends BottomSheetDialogFragment {
protected Context mContext;

protected View rootView;
protected BottomSheetDialog dialog;

protected BottomSheetBehavior mBehavior;
private BottomSheetBehavior.BottomSheetCallback mBottomSheetBehaviorCallback
        = new BottomSheetBehavior.BottomSheetCallback() {

    @Override
    public void onStateChanged(@NonNull View bottomSheet, int newState) {
        //禁止拖拽，
        if (newState == BottomSheetBehavior.STATE_DRAGGING) {
            //设置为收缩状态
            mBehavior.setState(BottomSheetBehavior.STATE_COLLAPSED);
        }
    }
    @Override
    public void onSlide(@NonNull View bottomSheet, float slideOffset) {
    }
};

@Override
public void onAttach(Context context) {
    super.onAttach(context);
    this.mContext = context;
}

@Override
public void onStart() {
    super.onStart();
    mBehavior.setState(BottomSheetBehavior.STATE_EXPANDED);
}

@Override
public void onDestroy() {
    super.onDestroy();
    //解除缓存View和当前ViewGroup的关联
    ((ViewGroup) (rootView.getParent())).removeView(rootView);
}


@Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
    //每次打开都调用该方法 类似于onCreateView 用于返回一个Dialog实例
    dialog = (BottomSheetDialog) super.onCreateDialog(savedInstanceState);
    if (rootView == null) {
        //缓存下来的View 当为空时才需要初始化 并缓存
        rootView = View.inflate(mContext, getLayoutResId(), null);
        initView();
    }
    resetView();
    //设置View重新关联
    dialog.setContentView(rootView);
    mBehavior = BottomSheetBehavior.from((View) rootView.getParent());
    mBehavior.setSkipCollapsed(true);
    mBehavior.setHideable(true);
    mBehavior.setBottomSheetCallback(mBottomSheetBehaviorCallback);
    //圆角边的关键(设置背景透明)
    //((View) rootView.getParent()).setBackgroundColor(Color.TRANSPARENT);
    //重置高度
    if (dialog != null) {
        View bottomSheet = dialog.findViewById(R.id.design_bottom_sheet);
        bottomSheet.getLayoutParams().height = ScreenUtils.getScreenHeight() * 2 / 3;
    }
    rootView.post(() ->{
        mBehavior.setPeekHeight(rootView.getHeight());
    });
    return dialog;
}

public abstract int getLayoutResId();

/**
 * 初始化View和设置数据等操作的方法
 */
public abstract void initView();

/**
 * 重置的View和数据的空方法 子类可以选择实现
 * 为避免多次inflate 父类缓存rootView
 * 所以不会每次打开都调用{@link #initView()}方法
 * 但是每次都会调用该方法 给子类能够重置View和数据
 */
public void resetView() {

}

public boolean isShowing() {
    return dialog != null && dialog.isShowing();
}

/**
 * 使用关闭弹框 是否使用动画可选
 * 使用动画 同时切换界面Aty会卡顿 建议直接关闭
 *
 * @param isAnimation
 */
public void close(boolean isAnimation) {
    if (isAnimation) {
        if (mBehavior != null)
            mBehavior.setState(BottomSheetBehavior.STATE_HIDDEN);
    } else {
        dismiss();
    }
}
}
aloneSingingStar/BottomSheetDemo

BottomSheetDemo
