Question

大家好我需要在包含几个uiimageviews的uiscrollview中添加zoom。这是我的代码我是如何做到的，但它无法正常工作

- (void)setupPage
{
    scrollView.delegate = self;

    [self.scrollView setBackgroundColor:[UIColor blackColor]];
    [scrollView setCanCancelContentTouches:NO];

    scrollView.indicatorStyle = UIScrollViewIndicatorStyleWhite;
    scrollView.clipsToBounds = YES;
    scrollView.scrollEnabled = YES;
    scrollView.pagingEnabled = YES;

    NSUInteger nimages = 0;
    CGFloat cx = 0;
    for (; ; nimages++) {
        //Maquette final_Print 2.png
        NSString *imageName = [NSString stringWithFormat:@"rint %d.png", (nimages + 1)];
        UIImage *image = [UIImage imageNamed:imageName];
        if (image == nil) {
            break;
        }
        imageView = [[UIImageView alloc] initWithImage:image];
        [imageView setContentMode:UIViewContentModeScaleToFill];
        CGRect rect = imageView.frame;
        rect.size.height = 1004;
        rect.size.width = 768;
        rect.origin.x = ((scrollView.frame.size.width - 768) / 2) + cx;
        rect.origin.y = ((scrollView.frame.size.height - 1004) / 2);

        imageView.frame = rect;

        [scrollView addSubview:imageView];
        [imageView release];

        cx += scrollView.frame.size.width;

    }


    [scrollView setContentSize:CGSizeMake(cx, 1004)];

    scrollView.minimumZoomScale = scrollView.frame.size.width / 768;
    scrollView.maximumZoomScale = 2.0;
    [scrollView setZoomScale:scrollView.minimumZoomScale];
}

//处理缩放的代码：

#pragma mark -
#pragma mark UIScrollView ZOOM

//- (void)scrollViewDidZoom:(UIScrollView *)scrollView {
//    imageView.frame = [self centeredFrameForScrollView:scrollView andUIView:imageView];;
//}

- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView {
    return imageView;
}

- (CGRect)centeredFrameForScrollView:(UIScrollView *)scroll andUIView:(UIView *)rView {
    CGSize boundsSize = scroll.bounds.size;
    CGRect frameToCenter = rView.frame;

    // center horizontally
    if (frameToCenter.size.width < boundsSize.width) {
        frameToCenter.origin.x = (boundsSize.width - frameToCenter.size.width) / 2;
    }
    else {
        frameToCenter.origin.x = 0;
    }

    // center vertically
    if (frameToCenter.size.height < boundsSize.height) {
        frameToCenter.origin.y = (boundsSize.height - frameToCenter.size.height) / 2;
    }
    else {
        frameToCenter.origin.y = 0;
    }

    return frameToCenter;
}

当我试图缩放它不按预期工作时。而且我也不能向左或向右滑动......

Answer 1

.m文件

-(UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView
{
  return self.theImageView;
}

- (CGRect)centeredFrameForScrollView:(UIScrollView *)scroll andUIView:(UIView *)rView {
  CGSize boundsSize = scroll.bounds.size;
  CGRect frameToCenter = rView.frame;
  // center horizontally
  if (frameToCenter.size.width < boundsSize.width) {
    frameToCenter.origin.x = (boundsSize.width - frameToCenter.size.width) / 2;
  }
  else {
    frameToCenter.origin.x = 0;
  }
  // center vertically
  if (frameToCenter.size.height < boundsSize.height) {
    frameToCenter.origin.y = (boundsSize.height - frameToCenter.size.height) / 2;
  }
  else {
    frameToCenter.origin.y = 0;
  }
  return frameToCenter;
}

-(void)scrollViewDidZoom:(UIScrollView *)scrollView
{
  self.theImageView.frame = [self centeredFrameForScrollView:self.theScrollView andUIView:self.theImageView];                               
}

- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response {
  [self.resourceData setLength:0];
  self.filesize = [NSNumber numberWithLongLong:[response expectedContentLength]];
}

-(void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data
{
  [self.resourceData appendData:data];
  NSNumber *resourceLength = [NSNumber numberWithUnsignedInteger:[self.resourceData length]];
  self.progressBar.progress = [resourceLength floatValue] / [self.filesize floatValue];
}

-(void)connectionDidFinishLoading:(NSURLConnection *)connection
{
  self.theImage = [[UIImage alloc]initWithData:resourceData];
  self.theImageView.frame = CGRectMake(0, 0, self.theImage.size.width, self.theImage.size.height);
  self.theImageView.image = self.theImage;
  self.theScrollView.minimumZoomScale = self.theScrollView.frame.size.width / self.theImageView.frame.size.width;
  self.theScrollView.maximumZoomScale = 2.0;
  [self.theScrollView setZoomScale:self.theScrollView.minimumZoomScale];
  self.theScrollView.contentSize = self.theImageView.frame.size;
  self.theLabel.hidden = YES;
  self.progressBar.hidden = YES;
}

-(void)setImageInImageView
{
  NSURLRequest *req = [[NSURLRequest alloc]initWithURL:[NSURL URLWithString:self.imageLink]];
  NSURLConnection *conn = [[NSURLConnection alloc]initWithRequest:req delegate:self];
  if (conn)
  {
    self.resourceData = [NSMutableData data];
  }
  else
  {
    NSLog(@"Connection failed: IMageViewerViewController");
  }
}

-(void)loadView
{
  self.filesize = [[NSNumber alloc]init];
  self.progressBar = [[UIProgressView alloc]initWithProgressViewStyle:UIProgressViewStyleBar];
  self.progressBar.frame = CGRectMake(20, 240, 280, 40);
  [self.progressBar setProgress:0.0];
  self.theImageView = [[[UIImageView alloc]initWithFrame:[[UIScreen mainScreen]applicationFrame]]autorelease];
  self.theScrollView = [[[UIScrollView alloc]initWithFrame:[[UIScreen mainScreen]applicationFrame]]autorelease];
  self.theScrollView.delegate = self;
  [self.theScrollView addSubview:self.theImageView];
  self.view = self.theScrollView;
  self.theLabel = [[UILabel alloc]initWithFrame:CGRectMake(0, 200, 320, 40)];
  self.theLabel.font = [UIFont boldSystemFontOfSize:15.0f];
  self.theLabel.text = @"Please wait, file is being downloaded";
  self.theLabel.textAlignment = UITextAlignmentCenter;
  self.theLabel.hidden = NO;
  [self.view addSubview:self.progressBar];
  [self.view bringSubviewToFront:self.progressBar];
  [self.view addSubview:self.theLabel];
  [self.view bringSubviewToFront:self.    theLabel];
  [self performSelectorOnMainThread:@selector(setImageInImageView) withObject:nil waitUntilDone:NO];
}

.h文件

@interface ImageViewerViewController : UIViewController<UIScrollViewDelegate, NSURLConnectionDelegate, NSURLConnectionDataDelegate>

@property (nonatomic, retain) IBOutlet UIImageView *theImageView;
@property (nonatomic, retain) IBOutlet UIScrollView *theScrollView;
@property (nonatomic, retain) NSString *imageLink;
@property (nonatomic, retain) UIImage *theImage;
@property (nonatomic, retain) UILabel *theLabel;
@property (nonatomic, retain) UIProgressView *progressBar;
@property (nonatomic, retain) NSMutableData *resourceData;
@property (nonatomic, retain) NSNumber *filesize;
@end

Answer 2

您需要做的只是在UIImageView内添加UIScrollView（或任何想要缩放的视图）。

将maxZoomScale上的UIScrollView设置为高于1.0f的任何值。

将自己设为UIScrollView的代理人，并在UIImageView委托方法中返回viewForZooming。

就是这样。不需要捏手势，没有任何东西。 UIScrollView为您处理缩放缩放。

UIscrollview如果imagesview如何添加缩放？

2 个答案: