ios 图片拖拽，捏，双击放大缩小，以及保存到相册

//
//  DetailPopStarView.h
//  Gukw
//

#import <UIKit/UIKit.h>
#import "AsyncImageView.h"

@interface DetailPopStarView : UIView<UIScrollViewDelegate>
@property (nonatomic) NSString *url;
@property (nonatomic) AsyncImageView *imgView;
@property (nonatomic) CGFloat width;
@property (nonatomic) CGFloat height;
@property (nonatomic) BOOL isTwiceTaping;
@property (nonatomic) BOOL isDoubleTapingForZoom;
@property (nonatomic) CGFloat currentScale;
@property (nonatomic) CGFloat offsetY;
@property (nonatomic) UIScrollView *scrollView;
@property (nonatomic) UIActivityIndicatorView *activityIndicatorView;
@property (nonatomic) CGFloat touchX;
@property (nonatomic) CGFloat touchY;

-(void) draw;
@end

//
//  DetailPopStarView.m
//
//

#import "DetailPopStarView.h"
#import "commonFunctions.h"

#define kScreenWidth  320.0
#define kScreenHeight  460.0
#define kMaxZoom 3.0

@implementation DetailPopStarView

@synthesize imgView = _imgView;
@synthesize url = _url;
@synthesize width = _width;
@synthesize height = _height;
@synthesize activityIndicatorView = _activityIndicatorView;
@synthesize isTwiceTaping = _isTwiceTaping;
@synthesize scrollView = _scrollView;
@synthesize currentScale = _currentScale;
@synthesize isDoubleTapingForZoom = _isDoubleTapingForZoom;
@synthesize  touchX = _touchX;
@synthesize  touchY = _touchY;
@synthesize offsetY = _offsetY;

- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
// Initialization code
}
return self;
}

// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
- (void)drawRect:(CGRect)rect
{

}

- (void) draw{
self.frame = CGRectMake(0, 0, kScreenWidth, kScreenHeight);
self.backgroundColor = [UIColor blackColor];
self.alpha = 0.0;

_scrollView = [[UIScrollView alloc] initWithFrame:CGRectMake(0, 0, kScreenWidth, kScreenHeight)];
[self addSubview:_scrollView];
_scrollView.delegate = self;
_scrollView.maximumZoomScale = 5.0;
CGFloat ratio = _width/_height*kScreenHeight/kScreenWidth;
CGFloat min = MIN(ratio, 1.0);
_scrollView.minimumZoomScale = min;

CGFloat height = _height /_width * kScreenWidth;
_imgView = [[AsyncImageView alloc] initWithFrame:CGRectMake(_scrollView.contentOffset.x+100, _scrollView.contentOffset.y+230, 10, 10)];
[_imgView loadImage:_url];

CGFloat y = (kScreenHeight - height)/2.0;
_offsetY = 0.0-y;
_scrollView.contentSize = CGSizeMake(kScreenWidth, height);
[_scrollView addSubview:_imgView];
_scrollView.contentOffset = CGPointMake(0, 0.0-y);

[UIView animateWithDuration:0.6
delay:0.0
options: UIViewAnimationCurveEaseOut
animations:^{
_imgView.frame = CGRectMake(0, 0, kScreenWidth, height);
self.alpha = 1.0;
}
completion:^(BOOL finished){
}
];

UITapGestureRecognizer *tapImgView = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tapImgViewHandle)];
tapImgView.numberOfTapsRequired = 1;
tapImgView.numberOfTouchesRequired = 1;
[self addGestureRecognizer:tapImgView];

UITapGestureRecognizer *tapImgViewTwice = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tapImgViewHandleTwice:)];
tapImgViewTwice.numberOfTapsRequired = 2;
tapImgViewTwice.numberOfTouchesRequired = 1;
[self addGestureRecognizer:tapImgViewTwice];
[tapImgView requireGestureRecognizerToFail:tapImgViewTwice];

UITapGestureRecognizer *saveTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(saveTapHandler)];
UIButton *save = [commonFunctions generateImage:@"save-pic-button.png" hover:@"save-pic-button-hover.png" withX:245 withY:420];
[save addGestureRecognizer:saveTap];
[self addSubview:save];

_activityIndicatorView = [commonFunctions generateActivityIndicatorView];
[self addSubview:_activityIndicatorView];
}

#pragma mark - UIscrollViewDelegate zoom

-(void)scrollViewDidEndZooming:(UIScrollView *)scrollView withView:(UIView *)view atScale:(float)scale{
_currentScale = scale;
NSLog(@"current scale:%f",scale);
}
-(UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView{
return _imgView;
}
-(void)scrollViewDidZoom:(UIScrollView *)scrollView{
//当捏或移动时，需要对center重新定义以达到正确显示未知
CGFloat xcenter = scrollView.center.x,ycenter = scrollView.center.y;
NSLog(@"adjust position,x:%f,y:%f",xcenter,ycenter);
xcenter = scrollView.contentSize.width > scrollView.frame.size.width?scrollView.contentSize.width/2 :xcenter;
ycenter = scrollView.contentSize.height > scrollView.frame.size.height ?scrollView.contentSize.height/2 : ycenter;
//双击放大时，图片不能越界，否则会出现空白。因此需要对边界值进行限制。
if(_isDoubleTapingForZoom){
NSLog(@"taping center");
xcenter = kMaxZoom*(kScreenWidth - _touchX);
ycenter = kMaxZoom*(kScreenHeight - _touchY);
if(xcenter > (kMaxZoom - 0.5)*kScreenWidth){//放大后左边超界
xcenter = (kMaxZoom - 0.5)*kScreenWidth;
}else if(xcenter <0.5*kScreenWidth){//放大后右边超界
xcenter = 0.5*kScreenWidth;
}
if(ycenter > (kMaxZoom - 0.5)*kScreenHeight){//放大后左边超界
ycenter = (kMaxZoom - 0.5)*kScreenHeight +_offsetY*kMaxZoom;
}else if(ycenter <0.5*kScreenHeight){//放大后右边超界
ycenter = 0.5*kScreenHeight +_offsetY*kMaxZoom;
}
NSLog(@"adjust postion sucess, x:%f,y:%f",xcenter,ycenter);
}
[_imgView setCenter:CGPointMake(xcenter, ycenter)];
}
#pragma mark - tap
-(void)tapImgViewHandle{
NSLog(@"%d",_isTwiceTaping);
if(_isTwiceTaping){
return;
}
NSLog(@"tap once");

[UIView animateWithDuration:0.6
delay:0.0
options: UIViewAnimationCurveEaseOut
animations:^{
_imgView.frame = CGRectMake(_scrollView.contentOffset.x+100, _scrollView.contentOffset.y+230, 10, 10);
self.alpha = 0.0;
}
completion:^(BOOL finished){
[self removeFromSuperview];
}
];

}
-(IBAction)tapImgViewHandleTwice:(UIGestureRecognizer *)sender{
_touchX = [sender locationInView:sender.view].x;
_touchY = [sender locationInView:sender.view].y;
if(_isTwiceTaping){
return;
}
_isTwiceTaping = YES;

NSLog(@"tap twice");

if(_currentScale > 1.0){
_currentScale = 1.0;
[_scrollView setZoomScale:1.0 animated:YES];
}else{
_isDoubleTapingForZoom = YES;
_currentScale = kMaxZoom;
[_scrollView setZoomScale:kMaxZoom animated:YES];
}
_isDoubleTapingForZoom = NO;
//延时做标记判断，使用户点击3次时的单击效果不生效。
[self performSelector:@selector(twiceTaping) withObject:nil afterDelay:0.65];
NSLog(@"sdfdf");
}
-(void)twiceTaping{
NSLog(@"no");
_isTwiceTaping = NO;
}
-(void) saveTapHandler{
if([_activityIndicatorView isAnimating]){
return;
}
[_activityIndicatorView startAnimating] ;
UIImageWriteToSavedPhotosAlbum(_imgView.image, self, @selector(imageSavedToPhotosAlbum: didFinishSavingWithError: contextInfo:), nil);
}
#pragma mark - savePhotoAlbumDelegate
- (void)imageSavedToPhotosAlbum:(UIImage *)image didFinishSavingWithError:(NSError *)error contextInfo:(void *) contextInfo {
NSString *message;
NSString *title;

[_activityIndicatorView stopAnimating];
if (!error) {
title = @"恭喜";
message = @"成功保存到相册";
} else {
title = @"失败";
message = [error description];
}
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:title message:message delegate:nil cancelButtonTitle:@"确定" otherButtonTitles:nil];
[alert show];
}

@end