Tip:為什麼設置文字的某個狀態時需要將其內容封裝為NSDictionary?這是因為字體所關聯的一系列屬性，如字體風格 字體顏色等。

設置圖片等多狀態的代碼風格，以下是一種，常見的其他控件設置多狀態一般也是以方法名set開頭（以Statexxx結尾），假如只有一種狀態，那麼直接使用 點( . )語法設置即可。

#pragma 處理字體點擊效果
- (void)dealWithItemFont:(UITabBarItem *)messageItem
{
    NSMutableDictionary *dic=[NSMutableDictionary dictionary];
    [dic setValue:[UIColor grayColor] forKey:NSForegroundColorAttributeName];
    [messageItem setTitleTextAttributes:dic forState:UIControlStateNormal ];
    NSMutableDictionary *hightlineDic=[NSMutableDictionary dictionary];
    [hightlineDic setValue:[UIColor orangeColor] forKey:NSForegroundColorAttributeName];
    [messageItem setTitleTextAttributes:hightlineDic forState:UIControlStateHighlighted];
}

#pragma 處理圖片點擊效果
- (UITabBarItem *)dealWithItemImage:(NSString *)normalImageStr selectedImageStr:(NSString *)selectedImageStr
{
    UIImage *normalImage=[UIImage imageNamed:normalImageStr];
    
    UIImage *selectedImage=[UIImage imageNamed:selectedImageStr];
    selectedImage=[selectedImage imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];
    UITabBarItem *messageItem=[[UITabBarItem alloc] init];
    [messageItem setImage:normalImage];
    [messageItem setSelectedImage:selectedImage];
    return messageItem;
}