IOS-系统相册

调用系统相册选择一张图片并显示出来，系统相册只能单选。

#import "ViewController.h"
#import <AVFoundation/AVFoundation.h>


@interface ViewController ()<UIImagePickerControllerDelegate,UINavigationControllerDelegate>

@property (nonatomic, strong) UIImageView *Image;

@end

@implementation ViewController


- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
 
    //创建按钮
    [self creatControl];
}

- (void)creatControl {
    //相册按钮
    scanBtn = [UIButton buttonWithType:UIButtonTypeSystem];
    scanBtn.frame = CGRectMake(100, 100, 100, 44);
    [scanBtn setTitle:@"打开相册" forState:UIControlStateNormal];
    [scanBtn addTarget:self action:@selector(scanBtnOnClick) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:scanBtn];
    
    //显示的相册图片
    self.Image = [[UIImageView alloc]initWithFrame:CGRectMake(100, 150, 200, 300)];
    [self.view addSubview:self.Image];
}

-(void)scanBtnOnClick {
    
    //打开之前一定要判断设备是否可用
    if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypePhotoLibrary]) {
        
        
        UIImagePickerController *photos = [[UIImagePickerController alloc]init];
        
        //数据源
        photos.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;

        //照片可编辑,在相册选中图片后会经过一个编辑框
        photos.allowsEditing =YES;

        //代理
        photos.delegate = self;
        
        
        //显示系统相册
        [self presentViewController:photos animated:YES completion:nil];
        
    }
    else {
        UIAlertController *alert = [UIAlertController alertControllerWithTitle:@"提示"
                                                                       message:@"当前设备不支持访问相册"
                                                                preferredStyle:UIAlertControllerStyleAlert];
        UIAlertAction *sureAction = [UIAlertAction actionWithTitle:@"确认"
                                                             style:UIAlertActionStyleDefault
                                                           handler:^(UIAlertAction * _Nonnull action) {
                                                           }];
        UIAlertAction *cancelAction = [UIAlertAction actionWithTitle:@"取消"
                                                               style:UIAlertActionStyleCancel
                                                             handler:^(UIAlertAction * _Nonnull action) {
                                                             }];
        [alert addAction:sureAction];
        [alert addAction:cancelAction];
        
        [self presentViewController:alert animated:YES completion:nil];
    }
    
}

#pragma mark - UIImagePickerControllerDelegate代理
-(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary<NSString *,id> *)info {
    //获取选中的原始图片
    UIImage *img = info[UIImagePickerControllerOriginalImage];
    
    //获取编辑后的图片
    UIImage *img1 = info[UIImagePickerControllerEditedImage];
    
    //显示或可以做其他任何操作
    self.Image.image = img;
   
    //一定要关闭相册界面
    [picker dismissViewControllerAnimated:YES completion:nil];
}

@end