YYXC_Student/jiaPei/QiNiu_IMSDK/QMChatRoom/ViewController/QMChatRoomShowImageController.m

//
//  QMChatRoomShowImageController.m
//  IMSDK-OC
//
//  Created by haochongfeng on 2017/5/17.
//  Copyright © 2017年 HCF. All rights reserved.
//

#import "QMChatRoomShowImageController.h"

@interface QMChatRoomShowImageController () <UIAlertViewDelegate,UINavigationControllerDelegate,UIScrollViewDelegate>

@end

@implementation QMChatRoomShowImageController

- (void)viewDidLoad {
    [super viewDidLoad];
    
    self.view.backgroundColor = [UIColor blackColor];
    
    //bigImageView
    self.bigImageView = [[UIImageView alloc] init];
    self.bigImageView.contentMode = UIViewContentModeScaleAspectFit;
    
    if ([self.picType isEqualToString:@"0"]) {
        NSString * filePath = [NSString stringWithFormat:@"%@/%@/%@",NSHomeDirectory(),@"Documents",self.picName];
        self.bigImageView.image = [UIImage imageWithContentsOfFile:filePath];
        [self myInit];
    }else {
        [self.bigImageView sd_setImageWithURL:[NSURL URLWithString:self.picName] placeholderImage:self.image];
        [self.bigImageView sd_setImageWithURL:[NSURL URLWithString:self.picName] completed:^(UIImage * _Nullable image, NSError * _Nullable error, SDImageCacheType cacheType, NSURL * _Nullable imageURL) {
            [self myInit];
        }];
    }
    
}

-(void)myInit{
    //sv
    UIScrollView *sv = [[UIScrollView alloc] initWithFrame:self.view.bounds];
    sv.minimumZoomScale = 1.0;
    sv.maximumZoomScale = 2.5;
    sv.delegate = self;
    [sv addSubview:self.bigImageView];
    [self.view addSubview:sv];
    
    //计算缩放scrollcontentVSize
    CGFloat rateK = kSize.width/kSize.height;
    if (self.bigImageView.image == nil) {
        return;
    }
    CGFloat rate = self.bigImageView.image.size.width/self.bigImageView.image.size.height;
    
    if (rate>rateK) {
        sv.contentSize = CGSizeMake(kSize.width, kSize.width/rate);
        self.bigImageView.frame = CGRectMake(0, 0, sv.contentSize.width, sv.contentSize.height);
        self.bigImageView.center = sv.center;
    }else{
        //        sv.contentSize = CGSizeMake(kSize.width, kSize.width/rate);
        sv.contentSize = CGSizeMake(kSize.height*rate, kSize.height);
        self.bigImageView.frame = CGRectMake(0, 0, sv.contentSize.width, sv.contentSize.height);
        self.bigImageView.center = sv.center;
    }
    
    
    //手势单击
    UITapGestureRecognizer * gestureRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tapHandle:)];
    UILongPressGestureRecognizer * pressGestureRecognizer = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(longPressAction:)];
    [self.bigImageView addGestureRecognizer:pressGestureRecognizer];
    self.bigImageView.userInteractionEnabled = YES;
    [sv addGestureRecognizer:gestureRecognizer];
    
    //双击
    UITapGestureRecognizer *doubleTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tapHandle:)];
    doubleTap.numberOfTapsRequired = 2;
    
    //单机必须在双击手势识别失败时,才能识别
    [gestureRecognizer requireGestureRecognizerToFail:doubleTap];
    
    [sv addGestureRecognizer:doubleTap];
}

//长按保存图片
- (void)longPressAction:(UILongPressGestureRecognizer *)pressGestureRecognizer {
    if (pressGestureRecognizer.state == UIGestureRecognizerStateBegan) {
        UIAlertView * alertView = [[UIAlertView alloc] initWithTitle:@"提示" message:@"保存图片" delegate:self cancelButtonTitle:@"取消" otherButtonTitles:@"确定", nil];
        [alertView show];
    }
}

//保存图片代理方法
- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex {
    if (buttonIndex == 1) {
        if ([self.picType isEqualToString:@"0"]) {
            NSString * filePath = [NSString stringWithFormat:@"%@/%@/%@",NSHomeDirectory(),@"Documents",self.picName];
            UIImage *image = [UIImage imageWithContentsOfFile:filePath];
            UIImageWriteToSavedPhotosAlbum(image, self, @selector(image:didFinishSavingWithError:contextInfo:),  nil);
        }else {
            NSURL * url = [NSURL URLWithString:self.picName];
            NSURLRequest * request = [NSURLRequest requestWithURL:url];
            NSOperationQueue * queue = [[NSOperationQueue alloc] init];
            [NSURLConnection sendAsynchronousRequest:request queue:queue completionHandler:^(NSURLResponse *response, NSData *data, NSError *connectionError) {
                UIImageWriteToSavedPhotosAlbum([UIImage imageWithData:data], self, @selector(image:didFinishSavingWithError:contextInfo:),  nil);
            }];
        }
    }
}

- (void)image:(UIImage *)image didFinishSavingWithError:(NSError *)error contextInfo:(void *)contextInfo
{
    if (!error) {
        ShowMsg(@"已保存到系统相册");
    }else{
        NSLog(@"image = %@, error = %@, contextInfo = %@", image, error, contextInfo);
    }
}


- (void)tapHandle:(UITapGestureRecognizer *)tap{
    
    if (tap.numberOfTapsRequired == 1) {
        [self dismissViewControllerAnimated:true completion:nil];
    } else if (tap.numberOfTapsRequired == 2) {
        UIScrollView *sv = (UIScrollView *)tap.view;
        if (sv.zoomScale != 1.0) {
            [sv setZoomScale:1.0 animated:YES];
        } else {
            CGPoint touchPoint = [tap locationInView:self.bigImageView];
            CGFloat newZoomScale = sv.maximumZoomScale;
            CGFloat xsize = self.view.frame.size.width / newZoomScale;
            CGFloat ysize = self.view.frame.size.height / newZoomScale;
            [sv zoomToRect:CGRectMake(touchPoint.x - xsize/2, touchPoint.y - ysize/2, xsize, ysize) animated:YES];
        }
    }
}

#pragma mark - sv代理

- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView
{
    return self.bigImageView;
}

- (void)scrollViewDidZoom:(UIScrollView *)scrollView {
    CGFloat offsetX = (scrollView.frame.size.width > scrollView.contentSize.width) ? ((scrollView.frame.size.width - scrollView.contentSize.width) * 0.5) : 0.0;
    CGFloat offsetY = (scrollView.frame.size.height > scrollView.contentSize.height) ? ((scrollView.frame.size.height - scrollView.contentSize.height) * 0.5) : 0.0;
    self.bigImageView.center = CGPointMake(scrollView.contentSize.width * 0.5 + offsetX, scrollView.contentSize.height * 0.5 + offsetY);
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

@end