iOS中scrollview自動滾動的實現
阿新 • • 發佈：2019-01-06
原問題是，我要展現給使用者的內容放在scrollview中，讓內容從上到底自動滾動，我最開始用的是DDAutoscrollview，但是無法實現。
一種解決方案見下邊，更多解決方案見：http://ask.csdn.net/questions/374
.h檔案
.m檔案
使用setContentOffset:animated:
如果需要開場動畫的效果，在scrollView的viewcontroller實現
移動的慢點，用timer實現：
一種解決方案見下邊，更多解決方案見：http://ask.csdn.net/questions/374
.h檔案
@interface Interface1 : UIViewController {
IBOutlet UIScrollView *scroller;
IBOutlet UILabel *warnung;
}
@property (nonatomic, retain) IBOutlet UIScrollView* scrollView;.m檔案
- (void)viewDidAppear:(BOOL)animated
{
[super viewDidAppear:animated];
CGPoint bottomOffset = CGPointMake(self.scrollView.contentOffset.x, self.scrollView.contentSize.height - self.scrollView.bounds.size.height);
[self.scrollView setContentOffset:bottomOffset animated:NO];
CGPoint newOffset = self.scrollView.contentOffset;
newOffset.y = 0;
[self.scrollView setContentOffset:newOffset animated:YES];
}
- (void)viewDidLoad
{
[scroller setScrollEnabled:YES];
[scroller setContentSize:CGSizeMake(320, 420)];
[super viewDidLoad];
}
使用setContentOffset:animated:
UIScrollView *scrollView = ...;
CGPoint newOffset = scrollView.contentOffset;
newOffset.y = 0;
[scrollView setContentOffset:newOffset animated:YES];如果需要開場動畫的效果，在scrollView的viewcontroller實現
- (void)viewDidLoad
{
[super viewDidLoad];
// ...
CGPoint bottomOffset = CGPointMake(self.scrollView.contentOffset.x, self.scrollView.contentSize.height - self.scrollView.bounds.size.height);
[self.scrollView setContentOffset:bottomOffset animated:NO];
}
- (void)viewDidAppear:(BOOL)animated
{
[super viewDidAppear:animated];
CGPoint newOffset = self.scrollView.contentOffset;
newOffset.y = 0;
[self.scrollView setContentOffset:newOffset animated:YES];
}
移動的慢點，用timer實現：
- (void)viewDidLoad
{
[super viewDidLoad];
// ...
CGPoint bottomOffset = CGPointMake(self.scrollView.contentOffset.x, self.scrollView.contentSize.height - self.scrollView.bounds.size.height);
[self.scrollView setContentOffset:bottomOffset animated:NO];
}
- (void)viewDidAppear:(BOOL)animated
{
[super viewDidAppear:animated];
CGPoint bottomOffset = CGPointMake(self.scrollView.contentOffset.x, self.scrollView.contentSize.height - self.scrollView.bounds.size.height);
//設定延遲時間
float scrollDurationInSeconds = 4.0;
//計算timer間隔
float totalScrollAmount = bottomOffset.y;
float timerInterval = scrollDurationInSeconds / totalScrollAmount;
[NSTimer scheduledTimerWithTimeInterval:timerInterval target:self selector:@selector(scrollScrollView:) userInfo:nil repeats:YES];
}
- (void)scrollScrollView:(NSTimer *)timer
{
CGPoint newScrollViewContentOffset = self.scrollView.contentOffset;
//向上移動 1px
newScrollViewContentOffset.y -= 1;
newScrollViewContentOffset.y = MAX(0, newScrollViewContentOffset.y);
//如果到頂了，timer中止
if (newScrollViewContentOffset.y == 0) {
[timer invalidate];
}
//最後設定scollView's contentOffset
self.scrollView.contentOffset = newScrollViewContentOffset;
}