iOS UIScrollView縮放增加空白區域

Question

我在UIScrollView中使用UIImageView實現縮放圖像。滾動視圖不會佔用全屏幕大小。我將scrollview的背景設爲綠色。然後我捏了一下圖像。

問題是，當我滾動縮放圖像時，它在滾動視圖中沒有正確居中，並且有一些右側和底部空間。如果我嘗試滾動到頂部或左側，則滾動視圖不允許以相似的空間滾動到圖像的末尾。空間的數量似乎與我捏手指時如何移動手指有關。

下面是截圖：

這裏是我的代碼：

// On viewWillAppear: 
- (void)loadMyImage 
{ 
    self.myImage.contentMode = UIViewContentModeScaleAspectFit; 
    self.myImage.image = self.originalImage; // an UIImage loaded from gallery 

    self.myImage.bounds = CGRectMake(0, 0, self.originalImage.size.width, self.originalImage.size.height); 
    self.scrollView.bounds = CGRectMake(0,0,320,200); 
    self.scrollView.frame = CGRectMake(0,0,320,200); 
    self.scrollView.minimumZoomScale=1.0f; 
    self.scrollView.maximumZoomScale=2.0f; 
    self.scrollView.delegate = self; 

    self.myImage.userInteractionEnabled = YES; 
} 

// Scroll view zooming events: 
- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView 
{return self.myImage;} 

- (void)scrollViewDidEndZooming:(UIScrollView *)scrollView withView:(UIView *)view atScale:(CGFloat)scale 
{ 
    CGSize boundsSize = self.scrollView.bounds.size; 
    CGRect contentsFrame = self.myImage.frame; 

    if (contentsFrame.size.width < boundsSize.width) { 
     contentsFrame.origin.x = (boundsSize.width - contentsFrame.size.width)/2.0f; 
    } else { 
     contentsFrame.origin.x = 0.0f; 
    } 

    if (contentsFrame.size.height < boundsSize.height) { 
     contentsFrame.origin.y = (boundsSize.height - contentsFrame.size.height)/2.0f; 
    } else { 
     contentsFrame.origin.y = 0.0f; 
    } 

    self.myImage.center = CGPointMake(
     contentsFrame.origin.x + contentsFrame.size.width/2.0f, 
     contentsFrame.origin.y + contentsFrame.size.height/2.0f); 

    CGPoint offset = CGPointMake(
     self.myImage.center.x - self.scrollView.bounds.size.width/2.0f, 
     self.myImage.center.y - self.scrollView.bounds.size.height/2.0f); 

    [UIView animateWithDuration:.25 animations:^{ 
     [self.scrollView setContentOffset:offset]; 
    }]; 

    NSLog(@"Final state of frame: %g x %g (%g , %g) and center (%g , %g)", 
      self.myImage.frame.size.width, self.myImage.frame.size.height, 
      self.myImage.frame.origin.x, self.myImage.frame.origin.y, 
      self.myImage.center.x, self.myImage.center.y); 
    NSLog(@"offset: (%g , %g)", 
      self.scrollView.contentOffset.x, self.scrollView.contentOffset.y); 
    NSLog(@"Inset left %g , right %g , top %g , bottom %g", 
      self.scrollView.contentInset.left, 
      self.scrollView.contentInset.right, 
      self.scrollView.contentInset.top, 
      self.scrollView.contentInset.bottom); 
    NSLog(@"=================================="); 
} 

這裏是我的輸出：

Initial state of bounds: 320 x 200 
of frame: 320 x 200 (0 , 0) and center (160 , 100) 
offset: (0 , 0) 
================================== 
Final state of frame: 640 x 400 (0 , 0) and center (320 , 200) 
offset: (160 , 100) 
Inset left 0 , right 0 , top 0 , bottom 0 
================================== 

我試着設置automaticallyAdjustsScrollViewInsets爲NO，但我的看法控制器不響應選擇器。此外，內嵌報告0-s。

任何解決方案或解決方法將是偉大的。任何想法或可能的解釋這種行爲也將不勝感激。

Answer 1

我建議你使用以下庫在Github上：

https://github.com/akhiljayaram/PJImageZoomView

不要忘了在你的ViewController添加

self.automaticallyAdjustsScrollViewInsets = NO; 

。
希望這有助於！ :)