「iOS開発」画像をダブルタップで拡大・縮小するサンプルコード

2017年4月15日

サンプルコード
1.demo.h
#import
@interface ZoomImage : NSObject
+(void)showImage:(UIImageView*)avatarImageView;
@end

2.demo.m
#import “ZoomImage.h"
static CGRect oldframe;
@implementation ZoomImage
+(void)showImage:(UIImageView*)avatarImageView
{
UIImage *image =avatarImageView.image;
// windowを取得
UIWindow *window =[UIApplication sharedApplication].keyWindow;
UIView *backgroundView =[[UIView alloc]initWithFrame:CGRectMake(0, 0, WIDTH, HEIGHT)];
oldframe =[avatarImageView convertRect:avatarImageView.bounds toView:window];
backgroundView.backgroundColor =[UIColor blackColor];
backgroundView.alpha =0.5;
UIImageView *imageView =[[UIImageView alloc]initWithFrame:oldframe];
imageView.image =image;
imageView.tag =1;
[backgroundView addSubview:imageView];
[window addSubview:backgroundView];
//縮小
UITapGestureRecognizer *tap =[[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(hideImage:)];
[backgroundView addGestureRecognizer:tap];
[UIView animateWithDuration:0.3 animations:^{
imageView.frame =CGRectMake(0,([UIScreen mainScreen].bounds.size.height-image.size.height*[UIScreen mainScreen].bounds.size.width/image.size.width)/2, [UIScreen mainScreen].bounds.size.width, image.size.height*[UIScreen mainScreen].bounds.size.width/image.size.width);
backgroundView.alpha =1;
}];
}
+(void)hideImage:(UITapGestureRecognizer *)tap{
UIView *backgroundView =tap.view;
UIImageView *imageView =(UIImageView *)[tap.view viewWithTag:1];
[UIView animateWithDuration:0.3 animations:^{
imageView.frame =oldframe;
backgroundView.alpha =0;
} completion:^(BOOL finished) {
[backgroundView removeFromSuperview];
}];
}