我制作了一个自定义 UIPickerView，但我希望 UILabel 在像这样滚动到选定行时更改颜色；

有什么想法吗？

编辑: 我想做的是在进行选择的同时更改 UILabel 的颜色，即在轮子转动时，而不是之后。

到目前为止，这是我所做的，它会在您做出选择后更改 UILabel 的颜色:

- (UIView *)pickerView:(UIPickerView *)pickerView viewForRow:(NSInteger)row forComponent:(NSInteger)component reusingView:(UIView *)view
{
    AILabel * pickerRow = view ? (AILabel *)view:[[[AILabel alloc] initWithFrame:CGRectMake(0, 0, 140, 40)] autorelease];
    pickerRow.backgroundColor = [UIColor clearColor];
    pickerRow.font = [UIFont boldSystemFontOfSize:18.0f];
    pickerRow.insets = UIEdgeInsetsMake(0, 10, 0, 0);

    if(component == 0)
    {
        pickerRow.text = [self.numberArray objectAtIndex:row];
        if ( row == number )
        {
            pickerRow.alpha = 0.0f;
            [UIView animateWithDuration: 0.33f
                                  delay: 0.0f
                                options: UIViewAnimationOptionCurveEaseOut
                             animations:^{
                                 pickerRow.textColor = [UIColor whiteColor];
                                 pickerRow.shadowColor = [UIColor blackColor];
                                 pickerRow.shadowOffset = CGSizeMake(0.0f, 1.0f);
                                 pickerRow.alpha = 1.0f;
                             }
                             completion:^(BOOL finished){
                             }];
        }
        else
        {
            pickerRow.textColor = [UIColor blackColor];
            pickerRow.shadowColor = [UIColor whiteColor];
            pickerRow.shadowOffset = CGSizeMake(0.0f, 1.0f);
        }
    }
    else
    {
        pickerRow.text = [self.durationArray objectAtIndex:row];
        if ( row == duration )
        {
            pickerRow.alpha = 0.0f;
            [UIView animateWithDuration: 0.33f
                                  delay: 0.0f
                                options: UIViewAnimationOptionCurveEaseOut
                             animations:^{
                                 pickerRow.textColor = [UIColor whiteColor];
                                 pickerRow.shadowColor = [UIColor blackColor];
                                 pickerRow.shadowOffset = CGSizeMake(0.0f, 1.0f);
                                 pickerRow.alpha = 1.0f;
                             }
                             completion:^(BOOL finished){
                             }];
        }
        else
        {
            pickerRow.textColor = [UIColor blackColor];
            pickerRow.shadowColor = [UIColor whiteColor];
            pickerRow.shadowOffset = CGSizeMake(0.0f, 1.0f);
        }
    }

    return pickerRow;
}

AILabel 只是一个自定义的 UILabel，没有什么特别之处。 'number' 变量是第一个组件中的当前选定值。 'duration' 变量是第二个组件中的当前选定值。

希望这更清楚

干杯

最佳答案

 - (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.textColor  = [UIColor RedColor];
        CGSize rowSize = [pickerView rowSizeForComponent:component];
        CGRect labelRect = CGRectMake (0, 0, rowSize.width, rowSize.height);
        [label setFrame:labelRect];

        return label;
    }



- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component
{
 UILabel *selectedRow = (UILabel *)[pickerView viewForRow:row forComponent:component];
        selectedRow.textColor = [UIColor blueColor];
}

关于iphone - UIPickerView 选中行标签颜色，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/16477598/