BottomNavigationView的使用及遇到的问题

1.使用的时候 item 数大于 3 个时会有位移
使用下面的类通过反射来修改

/**
 * 取消底部的动画效果
 */
public class BottomNavigationViewHelper {

    @SuppressLint("RestrictedApi")
    public static void disableShiftMode(BottomNavigationView view) {
        BottomNavigationMenuView menuView = (BottomNavigationMenuView) view.getChildAt(0);
        try {
            Field shiftingMode = menuView.getClass().getDeclaredField("mShiftingMode");
            shiftingMode.setAccessible(true);
            shiftingMode.setBoolean(menuView, false);
            shiftingMode.setAccessible(false);
            for (int i = 0; i < menuView.getChildCount(); i++) {
                BottomNavigationItemView item = (BottomNavigationItemView) menuView.getChildAt(i);
                //noinspection RestrictedApi
                item.setShiftingMode(false);
                // set once again checked value, so view will be updated
                //noinspection RestrictedApi
                item.setChecked(item.getItemData().isChecked());
            }
        } catch (NoSuchFieldException e) {
            Log.e("BNVHelper", "Unable to get shift mode field", e);
        } catch (IllegalAccessException e) {
            Log.e("BNVHelper", "Unable to change value of shift mode", e);
        }
    }
}

使用方法：

    bottomNavigationView  = findViewById(R.id.bottomNavigationView);
    BottomNavigationViewHelper.disableShiftMode(bottomNavigationView);

2.在使用了上面的方法后，如果混淆签名，还需要配置混淆文件,不能混淆这个成员变量！否则会失效的。

-keepclassmembers class android.support.design.internal.BottomNavigationMenuView { 
    boolean mShiftingMode; 
}