安卓底部导航栏的四种实现方式，纯原生安卓编写。资源为四种实现方式的源码。每种方式一个项目

int anim abc_fade_in 0x7f010000 int anim abc_fade_out 0x7f010001 int anim abc_grow_fade_in_from_bottom 0x7f010002 int anim abc_popup_enter 0x7f010003 int anim abc_popup_exit 0x7f010004 int anim abc_shrink_fade_out_from_bottom 0x7f010005 int anim abc_slide_in_bottom 0x7f010006 int anim abc_slide_in_top 0x7f010007 int anim abc_slide_out_bottom 0x7f010008 int anim abc_slide_out_top 0x7f010009 int anim abc_tooltip_enter 0x7f01000a int anim abc_tooltip_exit 0x7f01000b int anim btn_checkbox_to_checked_box_inner_merged_animation 0x7f01000c int anim btn_checkbox_to_checked_box_outer_merged_animation 0x7f01000d int anim btn_checkbox_to_checked_icon_null_animation 0x7f01000e int anim btn_checkbox_to_unchecked_box_inner_merged_animation 0x7f01000f int anim btn_checkbox_to_unchecked_check_path_merged_animation 0x7f010010 int anim btn_checkbox_to_unchecked_icon_null_animation 0x7f010011 int anim btn_radio_to_off_mtrl_dot_group_animation 0x7f010012 int anim btn_radio_to_off_mtrl_ring_outer_animation 0x7f010013 int anim btn_radio_to_off_mtrl_ring_outer_path_animation 0x7f010014 int anim btn_radio_to_on_mtrl_dot_group_animation 0x7f010015 int anim btn_radio_to_on_mtrl_ring_outer_animation 0x7f010016 int anim btn_radio_to_on_mtrl_ring_outer_path_animation 0x7f010017 int anim design_bottom_sheet_slide_in 0x7f010018 int anim design_bottom_sheet_slide_out 0x7f010019 int anim design_snackbar_in 0x7f01001a int anim design_snackbar_out 0x7f01001b int anim mtrl_bottom_sheet_slide_in 0x7f01001c int anim mtrl_bottom_sheet_slide_out 0x7f01001d int anim mtrl_card_lowers_interpolator 0x7f01001e int animator design_appbar_state_list_animator 0x7f020000 int animator design_fab_hide_motion_spec 0x7f020001 int animator design_fab_show_motion_spec 0x7f020002 int animator mtrl_btn_state_list_anim 0x7f020003 int animator mtrl_btn_unelevated_state_list_anim 0x7f020004 int animator mtrl_card_state_list_anim 0x7f020005 int animator mtrl_chip_state_list_anim 0x7f020006 int animator mtrl_extended_fab_change_size_motion_spec 0x7f020007 int animator mtrl_extended_fab_hide_motion_spec 0x7f020008 int animator mtrl_extended_fab_show_motion_spec 0x7f020009 int animator mtrl_extended_fab_state_list_animator 0x7f02000a int animator mtrl_fab_hide_motion_spec 0x7f02000b int animator mtrl_fab_show_motion_spec 0x7f02000c int animator mtrl_fab_transformation_sheet_collapse_spec 0x7f02000d int animator mtrl_fab_transformation_sheet_expand_spec 0x7f02000e int animator scale_with_alpha 0x7f02000f int attr actionBarDivider 0x7f030000 int attr actionBarItemBackground 0x7f030001 int attr actionBarPopupTheme 0x7f030002 int attr actionBarSize 0x7f030003 int attr actionBarSplitStyle 0x7f030004 int attr actionBarStyle 0x7f030005 int attr actionBarTabBarStyle 0x7f030006 int attr actionBarTabStyle 0x7f030007 int attr actionBarTabTextStyle 0x7f030008 int attr actionBarTheme 0x7f030009 int attr actionBarWidgetTheme 0x7f03000a int attr actionButtonStyle 0x7f03000b int attr actionDropDownStyle 0x7f03000c int attr actionLayout 0x7f03000d int attr actionMenuTextAppearance 0x7f03000e int attr actionMenuTextColor 0x7f03000f int attr actionModeBackground 0x7f030010 int attr actionModeCloseButtonStyle 0x7f030011 int attr actionModeCloseDrawable 0x7f030012 int attr actionModeCopyDrawable 0x7f030013 int attr actionModeCutDrawable 0x7f030014 int attr actionModeFindDrawable 0x7f030015 int attr actionModePasteDrawable 0x7f030016 int attr actionModePopupWindowStyle 0x7f030017 int attr actionModeSelectAllDrawable 0x7f030018 int attr actionModeShareDrawable 0x7f030019 int attr actionModeSplitBackground 0x7f03001a int attr actionModeStyle 0x7f03001b int attr actionModeWebSearchDrawable 0x7f03001c int attr actionOverflowButtonStyle 0x7f03001d int attr actionOverflowMenuStyle 0x7f03001e int attr actionProviderClass 0x7f03001f int attr actionTextColorAlpha 0x7f030020 int attr actionViewClass 0x7f030021 int attr activityChooserViewStyle 0x7f030022 int attr alertDialogButtonGroupStyle 0x7f030023 int attr alertDialogCenterButtons 0x7f030024 int attr alertDialogStyle 0x7f030025 int attr alertDialogTheme 0x7f030026 int attr allowStacking 0x7f030027 int attr alpha 0x7f030028 int attr alphabeticModifiers 0x7f030029 int attr altSrc 0x7f03002a int attr animate_relativeTo 0x7f03002b int attr animationMode 0x7f03002c int attr appBarLayoutStyle 0x7f03002d int attr applyMotionScene 0x7f03002e int attr arcMode 0x7f03002f int attr arrowHeadLength 0x7f030030 int attr arrowShaftLength 0x7f030031 int attr attributeName 0x7f030032 int attr autoCompleteTextViewStyle 0x7f030033 int attr autoSizeMaxTextSize 0x7f030034 int attr autoSizeMinTextSize 0x7f030035 int attr autoSizePresetSizes 0x7f030036 int attr autoSizeStepGranularity 0x7f030037 int attr autoSizeTextType 0x7f030038 int attr autoTransition 0x7f030039 int attr background 0x7f03003a int attr backgroundColor 0x7f03003b int attr backgroundInsetBottom 0x7f03003c int attr backgroundInsetEnd 0x7f03003d int attr backgroundInsetStart 0x7f03003e int attr backgroundInsetTop 0x7f03003f int attr backgroundOverlayColorAlpha 0x7f030040 int attr backgroundSplit 0x7f030041 int attr backgroundStacked 0x7f030042 int attr backgroundTint 0x7f030043 int attr backgroundTintMode 0x7f030044 int attr badgeGravity 0x7f030045 int attr badgeStyle 0x7f030046 int attr badgeTextColor 0x7f030047 int attr banner_default_image 0x7f030048 int attr banner_layout 0x7f030049 int attr barLength 0x7f03004a int attr barrierAllowsGoneWidgets 0x7f03004b int attr barrierDirection 0x7f03004c int attr barrierMargin 0x7f03004d int attr behavior_autoHide 0x7f03004e int attr behavior_autoShrink 0x7f03004f int attr behavior_draggable 0x7f030050 int attr behavior_expandedOffset 0x7f030051 int attr behavior_fitToContents 0x7f030052 int attr behavior_halfExpandedRatio 0x7f030053 int attr behavior_hideable 0x7f030054 int attr behavior_overlapTop 0x7f030055 int attr behavior_peekHeight 0x7f030056 int attr behavior_saveFlags 0x7f030057 int attr behavior_skipCollapsed 0x7f030058 int attr borderWidth 0x7f030059 int attr borderlessButtonStyle 0x7f03005a int attr bottomAppBarStyle 0x7f03005b int attr bottomNavigationStyle 0x7f03005c int attr bottomSheetDialogTheme 0x7f03005d int attr bottomSheetStyle 0x7f03005e int attr boxBackgroundColor 0x7f03005f int attr boxBackgroundMode 0x7f030060 int attr boxCollapsedPaddingTop 0x7f030061 int attr boxCornerRadiusBottomEnd 0x7f030062 int attr boxCornerRadiusBottomStart 0x7f030063 int attr boxCornerRadiusTopEnd 0x7f030064 int attr boxCornerRadiusTopStart 0x7f030065 int attr boxStrokeColor 0x7f030066 int attr boxStrokeErrorColor 0x7f030067 int attr boxStrokeWidth 0x7f030068 int attr boxStrokeWidthFocused 0x7f030069 int attr brightness 0x7f03006a int attr buttonBarButtonStyle 0x7f03006b int attr buttonBarNegativeButtonStyle 0x7f03006c int attr buttonBarNeutralButtonStyle 0x7f03006d int attr buttonBarPositiveButtonStyle 0x7f03006e int attr buttonBarStyle 0x7f03006f int attr buttonCompat 0x7f030070 int attr buttonGravity 0x7f030071 int attr buttonIconDimen 0x7f030072 int attr buttonPanelSideLayout 0x7f030073 int attr buttonStyle 0x7f030074 int attr buttonStyleSmall 0x7f030075 int attr buttonTint 0x7f030076 int attr buttonTintMode 0x7f030077 int attr cardBackgroundColor 0x7f030078 int attr cardCornerRadius 0x7f030079 int attr cardElevation 0x7f03007a int attr cardForegroundColor 0x7f03007b int attr cardMaxElevation 0x7f03007c int attr cardPreventCornerOverlap 0x7f03007d int attr cardUseCompatPadding 0x7f03007e int attr cardViewStyle 0x7f03007f int attr chainUseRtl 0x7f030080 int attr checkboxStyle 0x7f030081 int attr checkedButton 0x7f030082 int attr checkedChip 0x7f030083 int attr checkedIcon 0x7f030084 int attr checkedIconEnabled 0x7f030085 int attr checkedIconTint 0x7f030086 int attr checkedIconVisible 0x7f030087 int attr checkedTextViewStyle 0x7f030088 int attr chipBackgroundColor 0x7f030089 int attr chipCornerRadius 0x7f03008a int attr chipEndPadding 0x7f03008b int attr chipGroupStyle 0x7f03008c int attr chipIcon 0x7f0