在ios中放大和缩小图像时如何获取原始图像

Question

嗨，我是 ios 的初学者，在我的项目中，我在 UIScrollview 上添加 UIImage，我在 UIImage 上添加了点击手势

当我们双击 UIImage 时，图像应该在视图控制器上缩放全屏尺寸

在全屏大小的图像之后，我们可以按照我们想要的任何方式缩放它（我的意思是使用像捏缩放效果）这里我的要求是当我们双击图像时，图像需要设置它的原始位置我试过了水平最好，但我没有得到结果，请帮助我

我的代码如下：

#import "ViewController2.h"

@interface ViewController2 ()
{
    UIScrollView * myScroll;
    UITapGestureRecognizer *tap;
    BOOL isFullScreen;
    CGRect prevFrame;
    UIImageView * _imageView;
}

@end

@implementation ViewController2

- (void)viewDidLoad
{
    [super viewDidLoad];

    isFullScreen = FALSE;
    myScroll = [[UIScrollView alloc] init];
    myScroll.frame = self.view.bounds;
    myScroll.contentSize = CGSizeMake(_imageView.frame.size.width, _imageView.frame.size.height);
    myScroll.maximumZoomScale = 4.0;
    myScroll.minimumZoomScale = 1.0;
    myScroll.clipsToBounds = YES;
    myScroll.delegate = self;
    myScroll.backgroundColor = [UIColor lightGrayColor];
    [self.view addSubview:myScroll];

    _imageView = [[UIImageView alloc] initWithFrame:CGRectMake(10, 10, 300, 200)];
    _imageView.contentMode = UIViewContentModeScaleAspectFill;
    [_imageView setClipsToBounds:YES];
    _imageView.userInteractionEnabled = YES;
    _imageView.image = [UIImage imageNamed:@"ram.jpeg"];

    UITapGestureRecognizer *tapper = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(imgToFullScreen:)];
    tapper.numberOfTapsRequired = 1;
    [_imageView addGestureRecognizer:tapper];
    [myScroll addSubview:_imageView];
}

- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView {

    return _imageView;
}

-(void)imgToFullScreen:(UITapGestureRecognizer*)sender {

    if (!isFullScreen) {

        [UIView animateWithDuration:0.5 delay:0 options:0 animations:^{

            prevFrame = _imageView.frame;
            [_imageView setFrame:[[UIScreen mainScreen] bounds]];
        }completion:^(BOOL finished){
            isFullScreen = TRUE;
        }];
        return;
    }
    else{
        [UIView animateWithDuration:0.5 delay:0 options:0 animations:^{
            [_imageView setFrame:prevFrame];
        }completion:^(BOOL finished){
            isFullScreen = FALSE;
        }];
        return;
    }
}

@end

Answer 1

我对您的代码进行了一些修改，如下所示尝试一下。检查它是否提供您想要的输出。

@interface   ScrollViewController ()<UIScrollViewDelegate>{
        UIScrollView * myScroll;
        UITapGestureRecognizer *tap;
        BOOL isFullScreen;
        CGRect prevFrame;
        UIImageView * _imageView;
        CGAffineTransform trans;
    }



    @end

    @implementation ScrollViewController

    - (void)viewDidLoad {
        [super viewDidLoad];
        // Do any additional setup after loading the view from its nib.

        isFullScreen = FALSE;
        myScroll = [[UIScrollView alloc] init];
        myScroll.frame = [UIScreen mainScreen].bounds;
        myScroll.contentSize = CGSizeMake(prevFrame.size.width, prevFrame.size.height);
        myScroll.maximumZoomScale = 4.0;
        myScroll.minimumZoomScale = 1.0;
        myScroll.clipsToBounds = YES;
        myScroll.delegate = self;
        myScroll.backgroundColor = [UIColor lightGrayColor];
        [self.view addSubview:myScroll];

        _imageView = [[UIImageView alloc] initWithFrame:CGRectMake(10, 10, 300, 200)];
        _imageView.contentMode = UIViewContentModeScaleAspectFill;
        [_imageView setClipsToBounds:YES];
        _imageView.userInteractionEnabled = YES;
        _imageView.image = [UIImage imageNamed:@"img.png"];

        UITapGestureRecognizer *tapper = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(imgToFullScreen:)];
        tapper.numberOfTapsRequired = 2;
        [_imageView addGestureRecognizer:tapper];
        [myScroll addSubview:_imageView];

        prevFrame = _imageView.frame;
        trans = _imageView.transform;
    }

    - (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView {

        return _imageView;
    }

    -(void)imgToFullScreen:(UITapGestureRecognizer*)sender {


        if (!isFullScreen) {
             myScroll.contentSize = prevFrame.size;
            [UIView animateWithDuration:0.5 delay:0 options:0 animations:^{
                _imageView.frame = [UIScreen mainScreen].bounds;

            }completion:^(BOOL finished){
                isFullScreen = TRUE;

            }];
            return;
        }
        else{
            [UIView animateWithDuration:0.5 delay:0 options:0 animations:^{

                myScroll.contentSize = CGSizeMake(prevFrame.size.width, prevFrame.size.height);
                _imageView.transform = trans;
                _imageView.frame = prevFrame;


                NSLog(@"%@ %@",NSStringFromCGSize(myScroll.contentSize),NSStringFromCGRect(prevFrame));
            }completion:^(BOOL finished){
                isFullScreen = FALSE;

            }];
            return;
        }
    }