• 旧样式

UISearchController中SearchBar的旧有样式并不能满足，所以需要开发者对其做一定的修改，包括icon、文字、背景颜色等属性。

旧样式-不够时尚.png

• 新样式

未输入状态.png

搜索状态.png

- (void)configSearchBar {
    self.searchController = [[UISearchController alloc] initWithSearchResultsController:nil];
    self.searchController.searchResultsUpdater = self;
    self.searchController.searchBar.placeholder = @"It's new style.";
    self.searchController.searchBar.showsCancelButton = YES;
    self.searchController.searchBar.showsBookmarkButton = YES;
    self.tableView.tableHeaderView = self.searchController.searchBar;
    
    // 重新设置searchBar部分属性
    // 1. 修改搜索框圆角属性、边框
    UIView *SearchBarSearchFieldBackgroundView = [self subViewOfClassName:@"_UISearchBarSearchFieldBackgroundView" withView:self.searchController.searchBar];

    if (SearchBarSearchFieldBackgroundView) {
        SearchBarSearchFieldBackgroundView.layer.cornerRadius = 18;
        SearchBarSearchFieldBackgroundView.layer.borderColor = [UIColor darkGrayColor].CGColor;
        SearchBarSearchFieldBackgroundView.layer.borderWidth = 0.5;
        SearchBarSearchFieldBackgroundView.clipsToBounds = YES;
    }


    // 2. 修改颜色
    self.searchController.searchBar.tintColor = [UIColor whiteColor]; // 修改了右侧按钮的文字颜色、光标颜色
    self.searchController.searchBar.barTintColor = [UIColor colorWithRed:200/255.0 green:100/255.0 blue:180/255.0 alpha:1.0]; // 搜索框背景色


    // 3. 修改左侧放大镜、右侧booksicon（也可以修改clearButtonImage）
    [self.searchController.searchBar setImage:[UIImage imageNamed:@"clock"] forSearchBarIcon:UISearchBarIconSearch state:UIControlStateNormal];
    [self.searchController.searchBar setImage:[UIImage imageNamed:@"clock"] forSearchBarIcon:UISearchBarIconBookmark state:UIControlStateNormal];


    // 4. 搜索框文字颜色及背景色
    UITextField *textField = (UITextField *)[self subViewOfClassName:@"UISearchBarTextField" withView:self.searchController.searchBar];
    if (textField) {
        textField.textColor = [UIColor redColor];  // 搜索框文字的颜色
//        textField.backgroundColor = [[UIColor orangeColor] colorWithAlphaComponent:0.1];  // 搜索框背景色
    }


    // 5. 修改右侧取消按钮的相关属性
    UIButton *navigationButton = (UIButton *)[self subViewOfClassName:@"UINavigationButton" withView:self.searchController.searchBar];
    if (navigationButton) {
        [navigationButton setTitle:@"rightButton" forState:UIControlStateNormal];
        // 优先级高于barTintColor对button文字颜色的修改
        [navigationButton setTintColor:[UIColor blackColor]];
        navigationButton.backgroundColor = [[UIColor orangeColor] colorWithAlphaComponent:0.3];
    }
}

- (UIView*)subViewOfClassName:(NSString*)className withView:(UIView *)view{
    for (UIView* subView in view.subviews) {
        if ([NSStringFromClass(subView.class) isEqualToString:className]) {
            return subView;
        }
        
        UIView* resultFound = [self subViewOfClassName:className withView:subView];
        if (resultFound) {
            return resultFound;
        }
    }
    return nil;
}

• 补充

遍历来遍历去，我觉得想要一个自定义性更强的searchBar，最好还是用其它控件自定义(譬如：textField)，搜索图标，右侧取消按钮都可以自定义。

• 参考：

SearchBar属性及方法详细介绍
subViewOfClassName可以写成Category