iOS UIImagePickerController选择照片

#import "ViewController.h"

@interface ViewController ()<UINavigationControllerDelegate,UIImagePickerControllerDelegate>

@property (nonatomic, strong) UIImageView *imageView;

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    self.imageView.center = self.view.center;
    self.imageView.bounds = CGRectMake(0, 0, self.view.frame.size.width/2, self.view.frame.size.width/2);
    [self.view addSubview:self.imageView];
}


#pragma mark - UIImagePickerControllerDelegate
- (void)tap:(UITapGestureRecognizer *)sender {
        UIImagePickerController *imagePickerController = [[UIImagePickerController alloc]init];
        imagePickerController.delegate = self;
        imagePickerController.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
        imagePickerController.allowsEditing = YES;
        [self presentViewController:imagePickerController animated:YES completion:nil];
}

- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary<NSString *,id> *)info {
    UIImage *image = [info objectForKey:@"UIImagePickerControllerEditedImage"];
    self.imageView.image = image;
    [picker dismissViewControllerAnimated:YES completion:nil];
}
- (void)imagePickerControllerDidCancel:(UIImagePickerController *)picker {
    [picker dismissViewControllerAnimated:YES completion:nil];
}

#pragma mark -getters

- (UIImageView *)imageView {
    if (!_imageView) {
        _imageView = [[UIImageView alloc]init];
        _imageView.userInteractionEnabled = YES;
        _imageView.backgroundColor = [UIColor grayColor];
        _imageView.layer.borderColor = [UIColor blackColor].CGColor;
        _imageView.layer.borderWidth = 1.0f;
        UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(tap:)];
        [_imageView addGestureRecognizer:tap];
    }
    return _imageView;
}