系统UITabBar属性设置

设置背景： 

[_tabBar setBackgroundImage:[UIImage imageNamed:@"bg_tabbar"]];

设置某个Item选中的效果： 

_tabBar.selectionIndicatorImage = [UIImage imageNamed:@"bar_item_selected"];//设置选中效果图片

设置UITabBarItem文字颜色 

[[UITabBarItem appearance] setTitleTextAttributes:@{ UITextAttributeTextColor : [UIColor whiteColor] }
                                             forState:UIControlStateNormal];
    [[UITabBarItem appearance] setTitleTextAttributes:@{ UITextAttributeTextColor : [UIColor whiteColor] }
                                             forState:UIControlStateHighlighted];

设置UITabBarItem未选中与选中时的图片： 

[_hotTabItem setFinishedSelectedImage:[UIImage imageNamed:@"1_selected"] withFinishedUnselectedImage:[UIImage imageNamed:@"1"]];
    [_searchTabItem setFinishedSelectedImage:[UIImage imageNamed:@"2_selected"] withFinishedUnselectedImage:[UIImage imageNamed:@"2"]];
    [_userTabItem setFinishedSelectedImage:[UIImage imageNamed:@"3_selected"] withFinishedUnselectedImage:[UIImage imageNamed:@"3"]];