ios - 无法更改导航栏中搜索栏的文本和背景颜色

Question

我在我的导航栏中添加了一个搜索栏，并且想要更改文本和背景的颜色。我正在使用下面的代码并基于 SO appearanceWhenContainedIn 上的其他答案应该可以工作但什么都不做。这里出了什么问题？

UISearchBar * theSearchBar = [[UISearchBar alloc] initWithFrame:CGRectMake(0,0,320,40)]; // frame has no effect.

    theSearchBar.delegate = self;
    if ( !searchBarPlaceHolder ) {
        searchBarPlaceHolder = @"What are you looking for?";
    }
    theSearchBar.placeholder = searchBarPlaceHolder;
    theSearchBar.showsCancelButton = NO;

    [[UITextField appearanceWhenContainedIn:[UISearchBar class], nil] setTextColor:[UIColor redColor]];

    UISearchDisplayController *searchCon = [[UISearchDisplayController alloc]
             initWithSearchBar:theSearchBar
             contentsController:self ];

    [searchCon setActive:NO animated:YES];
    self.searchDisplayController = searchCon;
    self.searchDisplayController.delegate = self;
    self.searchDisplayController.searchResultsDataSource = self;
    self.searchDisplayController.searchResultsDelegate = self;
    self.searchDisplayController.displaysSearchBarInNavigationBar=YES;

Answer 1

以下代码帮助我解决了这个问题。我已经阅读了设置私有(private) API 的方法可能会被苹果拒绝，并且要走的路线是 subView。见下文:

    if(!itemSearchBar)
    {
        itemSearchBar = [[UISearchBar alloc] init];
        [itemSearchBar setFrame:CGRectMake(0, 0, self.view.frame.size.width, 55)];
        itemSearchBar.placeholder = @"What are you looking for?";
        itemSearchBar.delegate = self;


        UITextField* sbTextField;

        for (UIView *subView in self.itemSearchBar.subviews){
            for (UIView *ndLeveSubView in subView.subviews){

                if ([ndLeveSubView isKindOfClass:[UITextField class]])
                {

                    sbTextField = (UITextField *)ndLeveSubView;
                    //changes typing text color
                    sbTextField.textColor = [UIColor redColor];
                    //changes background color
                    sbTextField.backgroundColor = [UIColor blueColor];
                    //changes placeholder color
                            UIColor *color = [UIColor redColor];
                            sbTextField.attributedPlaceholder =
                            [[NSAttributedString alloc]
                             initWithString:@"What are you looking for?"
                             attributes:@{NSForegroundColorAttributeName:color}];

                    break;
                }

            }

        }