話不多說,直接上代碼

UIButton * button  = [UIButton buttonWithType:UIButtonTypeSystem];//這是用來調(diào)用相冊的button
button.frame = CGRectMake(100, 100, 100, 100);
button.backgroundColor = [UIColor greenColor];
[button addTarget:self action:@selector(buttonAction) forControlEvents:(UIControlEventTouchUpInside)];
[self.view addSubview:button];
    
    
UIImageView * imageView = [[UIImageView alloc]init];//展示相片的視圖
imageView.frame = CGRectMake(100, 220, 200, 200);
imageView.backgroundColor = [UIColor brownColor];
imageView.tag = 101;
[self.view addSubview: imageView];

- (void)buttonAction
{
    //創(chuàng)建圖片控制器
    UIImagePickerController * pc = [[[UIImagePickerController alloc]init] autorelease];
    pc.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
//    pc.sourceType = UIImagePickerControllerSourceTypeSavedPhotosAlbum;//相冊的另一種視圖形式
//    pc.sourceType = UIImagePickerControllerSourceTypeCamera這時候是照相使用的，使用的時候先判斷能不能使用相機，模擬機不能拍照，調(diào)用相冊不會用到

    
    //是否允許被編輯
    pc.allowsEditing = YES;
    
    //代理，這時候遵循一下代理
    pc.delegate = self;//因為delegete遵守了兩個協(xié)議，這里只需要一個協(xié)議，只遵守了一個
    
    
    //animated是否要動畫
    [self presentViewController:pc animated:YES completion:^{
        
    }];
    

}

UIImagePickerControllerDelegate協(xié)議里面的方法，注意先去遵循協(xié)議，才會有這個方法的提示

- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary<NSString *,id> *)info
{
    //把得到的相冊傳遞為標(biāo)記的ImageView
    UIImageView * img = (UIImageView *)[self.view viewWithTag:101];
    img.image = info[UIImagePickerControllerEditedImage];
    NSLog(@"%@",info);
    
    //退出
    [self dismissViewControllerAnimated:YES completion:^{

    } ];
    
}