我的下面的代码在 iOS 7 下运行良好 我试图在警报中添加选择器视图,在 ios7 版本下运行良好但在 ios 7 中它显示没有选择器视图的白色警报。
    -(void)showPinPickerAlert
    {
        numberarr = [[NSMutableArray alloc]initWithObjects:@"0",@"1",@"2",@"3",@"4",@"5",@"6",@"7",@"8",@"9", nil];
        UIAlertView *alert =[[UIAlertView alloc]initWithTitle:@"Enter Pin To Change Track me Option" message:@"\n\n\n\n\n\n\n" delegate:self cancelButtonTitle:@"Verify" otherButtonTitles:nil];
        UIPickerView *picker=[[UIPickerView alloc]initWithFrame:CGRectMake(25, 30, 230, 60) ];
        picker.dataSource=self;
        picker.delegate=self;
       // picker.backgroundColor=[UIColor blueColor];
        picker.showsSelectionIndicator = YES;
        //  picker.autoresizingMask = UIViewAutoresizingFlexibleHeight;
        picker.transform = CGAffineTransformMakeScale(0.6, 0.6);
        alert.tag=100;
        //  picker.transform = CGAffineTransformMakeScale(1, 0.2);
        [alert addSubview:picker];
        [alert show];
    }
- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView;
{
    return 4;
}
- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component
{
    strPin=[[NSString stringWithFormat:@"%i%i%i%i",[pickerView selectedRowInComponent:0],[pickerView selectedRowInComponent:1],[pickerView selectedRowInComponent:2],[pickerView selectedRowInComponent:3]]mutableCopy];
    NSLog(@"strPin=%@",strPin);
    // mlabel.text= [arrayNo objectAtIndex:row];
}
- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component;
{
    return [numberarr count];
}
**//code try to change color of picker text and background thats work fine in below ios7 but in iOS 7 still shows white screen**
- (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;
}
- (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component;
{
    pickerView.backgroundColor=[UIColor blackColor];
    return [numberarr objectAtIndex:row];
}
输出在下面 

IOS 7 中的输出

如何解决?