I got a problem about UIScrollView. I am making a custom view which inherits UIView. The view has a UIScrollView on which there are lots of buttons which should scroll left and right. The UIScrollView and buttons can show normally. But I cannot scroll the buttons. Could someone give me some suggestions? Thanks a lot!

MZMPhotoCalenderSwitcher.h

#import <UIKit/UIKit.h>

@interface MZMPhotoCalenderSwitcher : UIView <UIScrollViewDelegate>

@property (strong, nonatomic) UIScrollView *topSwitcher;

@end

MZMPhotoCalenderSwitcher.m

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view.
    self.topSwitcher = [[UIScrollView alloc] initWithFrame:CGRectMake(0, LABEL_HEIGHT + VIEW_Y, self.view.bounds.size.width, TOP_SWITCHER_HEIGHT)];
    self.topSwitcher.backgroundColor = [UIColor greenColor];
    self.topSwitcher.pagingEnabled = YES;
    self.topSwitcher.showsHorizontalScrollIndicator = NO;
    self.topSwitcher.showsVerticalScrollIndicator = NO;

    [self add:3 ButtonsOnView:self.topSwitcher withButtonWidth:44.8f andHeight:20.0f];
}

- (void)add:(int)num ButtonsOnView:(UIScrollView *)view withButtonWidth:(CGFloat)width andHeight:(CGFloat)height
{
    CGFloat totalTopSwitcherWidth = num * width;
    [view setContentSize:CGSizeMake(totalTopSwitcherWidth, view.bounds.size.height)];
    CGFloat xOffset = 0.0f;

    for (int i=1; i<=num; i++)
    {
        UIButton *button = [UIButton buttonWithType:UIButtonTypeRoundedRect];
        [button setFrame:CGRectMake(xOffset, 0, width, height)];
        xOffset += width;
        [button setTitle:[NSString stringWithFormat:@"%d", i] forState:UIControlStateNormal];

        button.titleLabel.font = [UIFont systemFontOfSize:10];
        [button setTitleColor:[UIColor blueColor] forState:UIControlStateNormal];
        [button setTitleColor:[UIColor blackColor] forState:UIControlStateSelected];
        [button setTag:i];
        [button addTarget:self action:@selector(buttonEvent) forControlEvents:UIControlEventTouchUpInside];

        if (i % 2 == 0)
            [button setBackgroundColor:[UIColor yellowColor]];
        else
            [button setBackgroundColor:[UIColor redColor]];

        [view addSubview:button];
    }
}