ios - UIPickerView 设置选定行的背景颜色(现在也适用于 iOS 14)

Question

我找到了这个代码 here :

- (UIView *)pickerView:(UIPickerView *)pickerView viewForRow:(NSInteger)row forComponent:(NSInteger)component reusingView:(UIView *)view
{
    UILabel *label = (UILabel*) view;
    if (label == nil)
    {
        label = [[UILabel alloc] init];
    }

    [label setText:@"Whatever"];

    // This part just colorizes everything, since you asked about that.

    [label setTextColor:[UIColor whiteColor]];
    [label setBackgroundColor:[UIColor blackColor]];
    CGSize rowSize = [pickerView rowSizeForComponent:component];
    CGRect labelRect = CGRectMake (0, 0, rowSize.width, rowSize.height);
    [label setFrame:labelRect];

    return label;
}

但是，正如评论中所述，它有一个问题:

It colorizes the labels, but not the picker, itself. So, when you roll to one end or the other, there's a blank spot where you can see the white background.

我只需要更改所选行的背景颜色。

Answer 1

我发现在 iOS 14 中，我现在在选择器的选定项目上获得了灰色背景颜色。目前的要求是摆脱它。
所以这似乎有效。

pickerView.subviews[safe:1]?.backgroundColor = UIColor.clear 

(“safe”是一个执行数组边界检查并在索引无效时返回 nil 的运算符)
我从这里得到了这个想法: https://stackoverflow.com/a/53740571/826946