UIScrollView + UIImage和缩放：不流畅 [英] UIScrollView + UIImage and zoom: not fluid

问题描述

我有视图控制器，里面有一个 UIScrollView ，用于管理缩放，以及 UIImage 。
现在我用处理缩放效果UIScrollViewDelegate 委托和方法 viewForZoomingInScrollView： ...但是结果很差，绝对不流畅！

I have view controller, and inside that I have a UIScrollView, for managing the zoom, and a UIImage. Now I'm handling the zoom effect with UIScrollViewDelegate delegate and method viewForZoomingInScrollView:... but the result is very poor, definitely not fluid!

这是我的代码：

#import "ImageViewController.h"

@interface ImageViewController () <UIScrollViewDelegate, UIActionSheetDelegate>
@property (strong, nonatomic) IBOutlet UIScrollView *scrollView;
@property (weak, nonatomic) IBOutlet UIImageView *imageView;

@end

@implementation ImageViewController

- (void)viewDidLoad {
    [super viewDidLoad];

    self.scrollView.delegate = self;
    self.scrollView.maximumZoomScale = 3.0;

    // some code
}

- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView {
    return self.imageView;
}
// last update
- (void)scrollViewDidZoom:(UIScrollView *)scrollView {
    if ([self.scrollView zoomScale] < 1.0) {
        [self.scrollView setZoomScale:1.0];
    }
}

// some other methods...

@end

这是故事板视图：

我没有使用Pinch手势识别器。
所有图片都非常小，如640x480。

I'm not using a Pinch Gesture Recognizer. All images are quite small like 640x480.

谢谢

P.S。这是 UICollectionView和图片的继续。

P.S. this is a continue of UICollectionView and images.

推荐答案

查看此我写的教程。第一部分正是您需要实现的。

Checkout out this tutorial I wrote. The first part is exactly what you need to implement.

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