iOS功能 - 使用UIRecognizer将图片添加手势（轻拍、捏合、拖动等）并存入系统相册 - 低头捡石頭

iOS功能 - 使用UIRecognizer将图片添加手势（轻拍、捏合、拖动等）并存入系统相册

准备工作

1 - 和 iOS 10 保存图片、调用相机一样，要 Info.plist 里面要涉及隐私数据时要添加一句提示语。打开 Info.plist 点击 + 号，在 Key 中输入：Privacy - Photo Library Additions Usage Description，Type 选 String，Value 中输入你的提示语。访问系统图库时用到的系统库时要引入头文 QuartzCore

2 - 代码示例：将图片添加手势（轻拍、捏合、拖动等），并实现截屏功能，最终截屏添加进系统相册。注：需要解决轻扫手势和拖动手势冲突的问题

#import "ViewController.h"
#import <QuartzCore/QuartzCore.h>
@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view.
    
    // 存放图片
    self.array = [NSArray  arrayWithObjects:
                  @"0F7129.jpg",
                  @"5B6FBE.jpg",
                  @"765F49.jpg",
                  @"A45453.jpg",
                  @"C6EECE.jpg",
                  @"D0347B.jpg",
                  nil];
    
    
    int W_Main = [UIScreen mainScreen].bounds.size.width;
    float W_Pic = (W_Main - 20*4)/3.0;// 图片宽度
    float H_Pic = W_Pic*1.3;  // 图片高度
    int n = 0;// 记录数组下标
    
    // 2行3列
    for (int i = 0; i < 2; i ++) {
        
        for (int j = 0; j < 3; j ++) {
     
            self.imageView = [[UIImageView alloc] initWithFrame:CGRectMake(W_Pic*j +20*(j+1), 80+H_Pic*i+20*(i+1), W_Pic, H_Pic)];
            self.imageView.userInteractionEnabled = YES;// 打开交互
            self.imageView.image = [UIImage imageNamed:[self.array objectAtIndex:n]];
            [self.view addSubview:self.imageView];
            [self.imageView release];
            n++;
            
            // 旋转手势j
            UIRotationGestureRecognizer *rotationGesture = [[UIRotationGestureRecognizer alloc] initWithTarget:self action:@selector(handleRotationGesture:)];
            [self.imageView addGestureRecognizer:rotationGesture];

            // 拖动手势
            UIPanGestureRecognizer *panGesture = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(handlePanGesture:)];
            [self.imageView addGestureRecognizer:panGesture];

            // 捏合：实现缩放
            UIPinchGestureRecognizer *pinchGesture = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:@selector(handlePinchGesture:)];
            [self.imageView addGestureRecognizer:pinchGesture];
            
            // 双击：先缩小、后放大
            UITapGestureRecognizer *doubleTapGesture = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleDoubleTapGesture:)];
            doubleTapGesture.numberOfTapsRequired = 2;// 设置双击；
            [self.imageView addGestureRecognizer:doubleTapGesture];

            // 长按：删除
            UILongPressGestureRecognizer * longPressGesture = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(handleLongPressGesture:)];
            
            longPressGesture.minimumPressDuration = 2.0;// 长按时间
            [self.imageView addGestureRecognizer:longPressGesture];
            
            // 轻扫手势
            UISwipeGestureRecognizer * swipeGesture = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(handleSwipeGesture:)];
            swipeGesture.direction =  UISwipeGestureRecognizerDirectionRight;
            [self.imageView addGestureRecognizer:swipeGesture];
            swipeGesture.direction =UISwipeGestureRecognizerDirectionLeft |UISwipeGestureRecognizerDirectionRight;
            
            // 解决拖动和轻扫的冲突
            [panGesture requireGestureRecognizerToFail:swipeGesture];
        }
    }
    
    // 截图
    UIButton *button = [UIButton buttonWithType:UIButtonTypeSystem];
    button.frame = CGRectMake(110, 500, W_Main-220, 30);
    button.backgroundColor = [UIColor cyanColor];
    [button setTitle:@"保存" forState:UIControlStateNormal];
    [button setTitle:@"保存中..." forState:UIControlStateHighlighted];
    [button addTarget:self action:@selector(saveIt) forControlEvents: UIControlEventTouchUpInside];
    [self.view addSubview:button];
    button.tag = 111;
    
}

// 轻扫
- (void)handleSwipeGesture:(UISwipeGestureRecognizer *)swipeGesture{
    //声明变量，随机图片下标
    int m = arc4random()%6;
    UIImageView *swipeImageView = (UIImageView *)swipeGesture.view;
       swipeImageView.image= [UIImage imageNamed:[self.array objectAtIndex:m]];
}

// 双击缩放
- (void)handleDoubleTapGesture:(UITapGestureRecognizer *)tapGesture{
    
    // 如果图片宽度为 120
    if (tapGesture.view.bounds.size.width==120) {
        tapGesture.view.bounds = CGRectMake(0, 0, tapGesture.view.frame.size.width/3, tapGesture.view.frame.size.height/3);
    // 放大1.5倍
    }else{
        tapGesture.view.bounds = CGRectMake(0, 0, tapGesture.view.bounds.size.width*1.5, tapGesture.view.bounds.size.height*1.5);
    }
}

// 长安删除
- (void)handleLongPressGesture:(UILongPressGestureRecognizer *)longPressGesture{
    if (longPressGesture.state ==UIGestureRecognizerStateBegan) {
        [longPressGesture.view removeFromSuperview];
    }
}

// 捏合
- (void)handlePinchGesture:(UIPinchGestureRecognizer *)pinchGesture{
    
    pinchGesture.view.transform = CGAffineTransformScale(pinchGesture.view.transform, pinchGesture.scale, pinchGesture.scale);
    pinchGesture.scale = 1.0;// 注意初始化
}

// 拖动
- (void)handlePanGesture:(UIPanGestureRecognizer *)panGesture{
    CGPoint offSet = [panGesture translationInView:panGesture.view];
    panGesture.view.transform = CGAffineTransformTranslate(panGesture.view.transform, offSet.x, offSet.y);
    [panGesture  setTranslation:CGPointZero inView:panGesture.view];
}

// 旋转
- (void)handleRotationGesture:(UIRotationGestureRecognizer *)rotationGesture{
    rotationGesture.view.transform = CGAffineTransformRotate(rotationGesture.view.transform, rotationGesture.rotation);
    rotationGesture.rotation = 0.0;
}

// 存储：保存到相册
- (void)saveIt{
    
        // 截屏大小
        UIGraphicsBeginImageContext(self.view.bounds.size);
        [self.view.layer renderInContext:UIGraphicsGetCurrentContext()];
        UIImage *viewImage = UIGraphicsGetImageFromCurrentImageContext();
        UIGraphicsEndImageContext();
        // 写入相册
        UIImageWriteToSavedPhotosAlbum(viewImage, nil, nil, nil);

        // 提示框
        UIAlertView * alert = [[UIAlertView alloc] initWithTitle:@"存储成功" message:@"您的图片成功保存到相册" delegate:nil cancelButtonTitle:@"确定"otherButtonTitles:nil];
        [alert show];
}


@end