UIScrollView cannot see ScrollBars/Indicators.

问题:

I programatically created a UISCrollView but i cant see the scrollbars/indicators.

UIScrollView * contentScrollView = [[UIScrollView alloc]initWithFrame:CGRectMake(760, 70, 205, 320)];
contentScrollView.delegate = self;
contentScrollView.scrollEnabled = YES;
contentScrollView.pagingEnabled = YES;
contentScrollView.userInteractionEnabled=YES;
contentScrollView.scrollsToTop = YES;
contentScrollView.showsVerticalScrollIndicator = NO;
contentScrollView.showsVerticalScrollIndicator = YES;
contentScrollView.alwaysBounceVertical = NO;
contentScrollView.alwaysBounceHorizontal = NO;
contentScrollView.bounces = NO;
contentScrollView.hidden = NO;
[contentScrollView flashScrollIndicators];
UILabel *titleLable = [[UILabel alloc] initWithFrame:CGRectMake(10, 10, 205, 40)];
UILabel *subtitleLable = [[UILabel alloc] initWithFrame:CGRectMake(10, 60, 205, 50)];
UITextView * mainContent = [[UITextView alloc]initWithFrame:CGRectMake(10, 110, 205, 230)];

[titleLable setText:@"...."];
[subtitleLable setText:@"SUbtitle"];
[mainContent setText:@"Descritpon"];
[contentScrollView addSubview:mainContent];
[contentScrollView addSubview:titleLable];
[contentScrollView addSubview:subtitleLable];

This code i add it to a view which is again attached to another bigger scrollview.. Does anyone know why this is the case? Also for simplicity i have reduced the text each lable contains to words but in the program i have the text is sufficient to scroll

Thanks..

回答1:

For the scroll view to scroll, the content size for the scroll view must be greater than its bounds. Please add this line and then check:

contentScrollView.contentSize=CGSizeMake(320, 250);

and also set the contentScrollView.bounces to YES and remove the line contentScrollView.showsVerticalScrollIndicator=YES as you have first set the value to NO and then YES.

This should do the job.

回答2:

contentScrollView.showsHorizontalScrollIndicator = YES;
contentScrollView.showsVerticalScrollIndicator = YES;