ScrollView內存問題

我想加載到scrollview 50 PNG圖像，我選擇通過延遲加載來做到這一點。但是我仍然有很大的內存問題，當我滾動30頁時，我的應用程序崩潰。ScrollView內存問題

請幫助我瞭解爲什麼會出現這種情況，我的代碼是：

UIImage *1 = [UIImage imageWithContentsOfFile:[[NSBundle mainBundle] pathForResource:@"30" ofType:@"png"]]; 
.... 
imageArray = [NSArray arrayWithObjects:1,2,3,4, ...]; 

- (void)loadPage:(NSInteger)page 
{ 
    if (page < 0 || page >= imageArray.count) 
    { 
     return; 
    } 

    UIView *pageView = [pageViews objectAtIndex:page]; 
    if ((NSNull*)pageView == [NSNull null]) 
    { 

     CGRect frame = self.scrollView.bounds; 
     frame.origin.x = frame.size.width * page; 
     frame.origin.y = 0.0f; 


     UIImageView *newPageView = [[UIImageView alloc] initWithImage:[imageArray objectAtIndex:page]]; 
     newPageView.contentMode = UIViewContentModeScaleAspectFit; 
     newPageView.frame = frame; 
     [self.scrollView addSubview:newPageView]; 
     [pageViews replaceObjectAtIndex:page withObject:newPageView]; 
    } 
} 


- (void)purgePage:(NSInteger)page 
{ 
    if (page < 0 || page >= imageArray.count) 
    { 
     return; 
    } 

    UIView *pageView = [pageViews objectAtIndex:page]; 
    if ((NSNull*)pageView != [NSNull null]) 
    { 
     [pageView removeFromSuperview]; 
     [pageViews replaceObjectAtIndex:page withObject:[NSNull null]]; 
    } 
} 


- (void)loadVisiblePages 
{ 
    CGFloat pageWidth = self.scrollView.frame.size.width; 
    NSInteger page = (NSInteger)floor((self.scrollView.contentOffset.x * 2.0f + pageWidth)/(pageWidth * 2.0f)); 

    self.pageControl.currentPage = page; 

    // Work out which pages you want to load 
    NSInteger firstPage = page - 1; 
    NSInteger lastPage = page + 1; 

    // Purge anything before the first page 
    for (NSInteger i=0; i<firstPage; i++) 
    { 
     [self purgePage:i]; 
    } 

    for (NSInteger i=firstPage; i<=lastPage; i++) 
    { 
     [self loadPage:i]; 
    } 

    for (NSInteger i=lastPage+1; i<imageArray.count; i++) 
    { 
     [self purgePage:i]; 
    } 

    NSString *string = [NSString stringWithFormat:@"%i.png",page+1]; 
    layer = [UIImage imageNamed:string]; 
}

來源

2012-04-03 Macaret

in puragePage :, set pageView = nil將其替換爲NSNull實例後。看看這是否給你一個更好的性能結果。 – jmstone617 2012-04-03 22:52:34

我發現這個問題，它正在創建newPageView。所以我改變了以下，我的應用程序現在不會崩潰。

UIImageView *newPageView = [[UIImageView alloc] initWithImage:[UIImage imageWithContentsOfFile:[[NSBundle mainBundle] pathForResource:string ofType:@"png"]]];

謝謝你的幫助。

來源

2012-04-04 07:27:52 Macaret

你應該將它添加到陣列瀏覽量釋放後newPageView。

來源

2012-04-03 08:53:32 mifki

我有ARC啓用，所以我不能手動釋放。 – Macaret 2012-04-03 09:32:03

ScrollView內存問題

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