Question

我已经以编程方式在视图内部创建了一个imageview，而不是使用storyboard。我为该视图添加了捏手势识别器..但它应该以特定比例的各种方式捏图像？有没有办法做到这一点？

-(void)handlePinchWithGestureRecognizer:(UIPinchGestureRecognizer *)pinchGestureRecognizer{

CGFloat lastScale = 1.0;
if([pinchGestureRecognizer state] == UIGestureRecognizerStateBegan) {
    // Reset the last scale, necessary if there are multiple objects with different scales
    lastScale = [pinchGestureRecognizer scale];
}

if ([pinchGestureRecognizer state] == UIGestureRecognizerStateBegan ||
    [pinchGestureRecognizer state] == UIGestureRecognizerStateChanged) {

    CGFloat currentScale = [[[pinchGestureRecognizer view].layer valueForKeyPath:@"transform.scale"] floatValue];

    // Constants to adjust the max/min values of zoom
    const CGFloat kMaxScale = 2.0;
    const CGFloat kMinScale = 1.0;

    CGFloat newScale = 1 -  (lastScale - [pinchGestureRecognizer scale]);
    newScale = MIN(newScale, kMaxScale / currentScale);
    newScale = MAX(newScale, kMinScale / currentScale);
    self.documentImageView.transform = CGAffineTransformScale(self.documentImageView.transform, newScale, newScale);

    lastScale = [pinchGestureRecognizer scale];  // Store the previous scale factor for the next pinch gesture call
}
}
- (void)viewDidAppear:(BOOL)animated {
[super viewDidAppear:animated];

UIPinchGestureRecognizer *pinchGestureRecognizer = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:@selector(handlePinchWithGestureRecognizer:)];
[self.documentImage addGestureRecognizer:pinchGestureRecognizer];
}

//

- (void)setExtractedImageForTableView:(UIImage *)extractedImage {
self.documentImageView.image = nil;
self.documentImageView = nil;
self.documentImageView = [[UIImageView alloc] initWithImage:extractedImage];
self.documentImageView.contentMode = UIViewContentModeScaleAspectFit;
if (!CGSizeEqualToSize(extractedImage.size, CGSizeZero)) {
    self.documentImageView.frame = CGRectMake(CGRectGetMinX(self.view.frame), CGRectGetMinY(self.tableView.frame) + 70, CGRectGetWidth(self.view.frame), (extractedImage.size.height/extractedImage.size.width) * CGRectGetWidth(self.view.frame));
    self.segmentedView.frame = self.documentImage.frame;
    [self.segmentedView addSubview:self.segment];
    [self.segmentedView addSubview:self.documentImageView];
    [self.tableView.tableHeaderView addSubview:self.segment];
    [self.tableView.tableHeaderView addSubview:self.documentImageView];
    CGRect frame = self.documentImageView.frame;
    frame.size.height = self.documentImageView.frame.size.height + 100;
    self.tableView.frame = CGRectMake(0, 0, 400, 300);
    self.tableView.tableHeaderView.frame = frame;
}
}

Answer 1

我认为您错过了添加以下内容

[self.documentImageView setUserInteractionEnabled:YES];

希望这会奏效。

图像+捏手势识别器

1 个答案: