iOS 选择图片库

懒加载

#pragma mark - lazy load
-(UIImageView *)imageView
{
    if (!_imageView) {
        _imageView = [[UIImageView alloc] initWithFrame:CGRectMake(100.0f, 100.0f, 100.0f, 100.0f)];
        _imageView.backgroundColor = [UIColor redColor];
        _imageView.userInteractionEnabled = YES;
        UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(imageClick)];
        [_imageView addGestureRecognizer:tap];
        [self.view addSubview:_imageView];
    }
    return _imageView;
}

-(UIImagePickerController *)imagePickerController
{
    if (!_imagePickerController) {
        _imagePickerController = [[UIImagePickerController alloc] init];
        _imagePickerController.delegate = self;
        _imagePickerController.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
        _imagePickerController.allowsEditing = YES;
    }
    return _imagePickerController;
}

遵循代理<UINavigationControllerDelegate,UIImagePickerControllerDelegate>

#pragma mark - click
-(void)imageClick
{
    [self presentViewController:self.imagePickerController animated:YES completion:NULL];
}


#pragma mark - UIImagePickerControllerDelegate
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary<UIImagePickerControllerInfoKey, id> *)info
{
    UIImage *image = [info objectForKey:UIImagePickerControllerEditedImage];
    self.imageView.image = image;
    NSLog(@" %@ ",info);
    [self dismissViewControllerAnimated:YES completion:NULL];
}