使用Photos来获取相册中所有图片

#import "AllPhotoViewController.h"
#import <Photos/Photos.h>
#import "ImageViewController.h"
@interface AllPhotoViewController ()<UICollectionViewDelegate,UICollectionViewDataSource,UINavigationControllerDelegate,UIImagePickerControllerDelegate>
@property(nonatomic,strong)UICollectionView *collectionView;
@property(nonatomic,strong)NSMutableArray *imageArr;
@property(nonatomic,strong)NSMutableArray <PHAsset*>
*assets;
@property(nonatomic,strong)UILabel *titleLabel;
@property(nonatomic,assign)CGSize size;
@property(nonatomic,strong)UIImagePickerController *imagePicker;
@end

@implementation AllPhotoViewController

- (void)viewDidLoad {
    [super
viewDidLoad];
    self.view.backgroundColor = [UIColor
whiteColor];
    [self
createNav];
    [self
createView];
    [self
loadImage];
    
}
-(void)createNav{
    UIFont *font;
    CGRect frame;
    if ([[UIDevice
currentDevice ]userInterfaceIdiom]==UIUserInterfaceIdiomPad) {
        font = [UIFont
systemFontOfSize:11.0/375*ScreenWidth];
        frame = CGRectMake(0, 0, 8.0/375*ScreenWidth, 15.0/375*ScreenWidth);
    }else{
        font = [UIFont
systemFontOfSize:16.0/375*ScreenWidth];
        frame = CGRectMake(0, 0, 15.0/375*ScreenWidth, 25.0/375*ScreenWidth);
    }
    self.titleLabel= [MyTools
createLabelWithText:@"全部照片(0)"
andFont:font andTextAlignment:1
andTextColor:[UIColor
whiteColor]];
    self.titleLabel.frame =
CGRectMake(0, 0, 100, 20);
    
    self.navigationItem.titleView =
self.titleLabel ;
    
    UIButton *back = [MyTools
createButtonWithFrame:frame
andBgImageName:@"scanback"];
    [back addTarget:self
action:@selector(goBack)
forControlEvents:UIControlEventTouchUpInside];
    self.navigationItem.leftBarButtonItem = [[UIBarButtonItem
alloc]initWithCustomView:back];
    CGRect tframe;
    if (IsPad) {
        tframe =  CGRectMake(0, 0, 18.0/375*ScreenWidth, 13.0/375*ScreenWidth);
    }
    else{
        tframe =  CGRectMake(0, 0, 25.0/375*ScreenWidth, 18.0/375*ScreenWidth);
    }
    
    UIButton *takePhoto = [MyTools
createButtonWithFrame:tframe
andBgImageName:@"zhaoxiangji"];
    [takePhoto addTarget:self
action:@selector(goTake)
forControlEvents:UIControlEventTouchUpInside];
    self.navigationItem.rightBarButtonItem = [[UIBarButtonItem
alloc]initWithCustomView:takePhoto];
    
}
-(void)goTake{
    [self
presentViewController:self.imagePicker
animated:YES
completion:nil];
    
}

-(void)goBack{
    [self.navigationController
popViewControllerAnimated:YES];
    
}
-(void)createView{
    self.imageArr = [NSMutableArray
array];
    UICollectionViewFlowLayout *layout = [[UICollectionViewFlowLayout
alloc]init];
    layout.minimumLineSpacing = 10;
    layout.minimumInteritemSpacing = 10;
    
    if ([[UIDevice
currentDevice]userInterfaceIdiom] ==
UIUserInterfaceIdiomPad) {
        self.size =
CGSizeMake(50.0/375*ScreenWidth, 35.0/375*ScreenWidth);
    }else{
        self.size =
CGSizeMake(100.0/375*ScreenWidth, 70.0/375*ScreenWidth);
    }
    layout.itemSize =
self.size;
    self.collectionView  = [[UICollectionView
alloc]initWithFrame:CGRectMake(10.0/375*ScreenWidth, 10.0/375*ScreenWidth,
ScreenWidth -  20.0/375*ScreenWidth,
ScreenHeight) collectionViewLayout:layout];
    self.collectionView.delegate =
self;
    self.collectionView.dataSource =
self;
    self.collectionView.backgroundColor = [UIColor
whiteColor];
    self.collectionView.showsVerticalScrollIndicator =
NO;
    [self.collectionView
registerClass:[UICollectionViewCell
class] forCellWithReuseIdentifier:@"cell"];
    [self.view
addSubview:_collectionView];
}

//从相册获取图片
-(void)loadImage{
    PHAuthorizationStatus status = [PHPhotoLibrary
authorizationStatus];
    if (status ==
PHAuthorizationStatusRestricted ||
        status == PHAuthorizationStatusDenied) {
        [AlertView
alertWithTarget:self
andMessage:@"设置访问权限打开相册"
andConfirm:^(UIAlertAction *action) {
            NSLog(@"点击了确定");
        }];
    }
    
    self.assets =  [self
getAllAssetInPhotoAblumWithAscending:YES];
    _titleLabel.text = [NSString
stringWithFormat:@"全部图片(%ld)",_assets.count];
    for (PHAsset *set
in _assets) {
        PHImageRequestOptions *options = [[PHImageRequestOptions
alloc] init];
        options.deliveryMode =
PHImageRequestOptionsDeliveryModeHighQualityFormat;
        
        [[PHImageManager
defaultManager] requestImageForAsset:set
targetSize:[UIScreen
mainScreen].bounds.size
contentMode:PHImageContentModeAspectFit
options:options resultHandler:^(UIImage *result,
NSDictionary *info) {
            //设置图片
            [self.imageArr
addObject:result];
            [self.collectionView
reloadData];
        }];
        //NSLog(@"%ld",_imageArr.count);
        
    }
}

-(UIImagePickerController *)imagePicker{
    if (_imagePicker ==
nil) {
        _imagePicker = [[UIImagePickerController
alloc]init];
        if ([UIImagePickerController
isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]) {
            _imagePicker .sourceType =
UIImagePickerControllerSourceTypeCamera;
            //设置拍摄照片
            _imagePicker.cameraCaptureMode =
UIImagePickerControllerCameraCaptureModePhoto;
            _imagePicker.allowsEditing =
YES;
 
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          _imagePicker.delegate =
self;
        } else {
            [AlertView
alertWithTarget:self
andMessage:@"摄像头无法使用"
andConfirm:nil];
        }
    }
    return
_imagePicker;
}

#pragma mark-- imagePicker的代理
-(void)imagePickerControllerDidCancel:(UIImagePickerController *)picker{
    [picker dismissViewControllerAnimated:YES
completion:nil];
}
-(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary<NSString
*,id> *)info{
    //获取到图片
    UIImage *image = [info
objectForKey:UIImagePickerControllerEditedImage];
    //保存照片到相册
    UIImageWriteToSavedPhotosAlbum(image,
self, @selector(image:didFinishSavingWithError:contextInfo:),
nil);
    
    [picker dismissViewControllerAnimated:YES
completion:nil];
}
-(void)image:(UIImage*)image didFinishSavingWithError:(NSError*)error contextInfo:(void*)contextInfo
{
      if (error) {
        //error非nil保存失败
        NSLog(@"%@
保存失败",[error
localizedDescription]);
    }else
    {
        //保存成功
        NSLog(@"保存成功");
        [_imageArr
addObject:image];
        [_collectionView
reloadData];
    }
}

#pragma mark -- collection代理
-(NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section{
    NSLog(@"%ld",_imageArr.count);
    return
_imageArr.count;
}
-(UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath
*)indexPath{
    UICollectionViewCell *cell = [collectionView
dequeueReusableCellWithReuseIdentifier:@"cell"
forIndexPath:indexPath];
    
    UIImage *image =
_imageArr[indexPath.row];
    //CGFloat height = image.size.height/image.size.width*100.0/375*ScreenWidth;
    UIImageView *imageView = [[UIImageView
alloc]initWithFrame:cell.bounds];
    imageView.image = image;
    [cell.contentView
addSubview:imageView];
    return cell;
}

-(void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath
*)indexPath{
    ImageViewController *imageV = [[ImageViewController
alloc]init];
    [self.navigationController
pushViewController:imageV
animated:YES];
    
}

#pragma mark - 获取相册内所有照片资源  
- (NSMutableArray<PHAsset *> *)getAllAssetInPhotoAblumWithAscending:(BOOL)ascending
{
    NSMutableArray<PHAsset *> *assets = [NSMutableArray
array];
    
    PHFetchOptions *option = [[PHFetchOptions
alloc] init];
    //ascending 为YES时，按照照片的创建时间升序排列;为NO时，则降序排列
    option.sortDescriptors = @[[NSSortDescriptor
sortDescriptorWithKey:@"creationDate"
ascending:ascending]];
    
    PHFetchResult *result = [PHAsset
fetchAssetsWithMediaType:PHAssetMediaTypeImage
options:option];
    
    [result enumerateObjectsUsingBlock:^(id 
_Nonnull obj, NSUInteger idx,
BOOL * _Nonnull stop) {
        PHAsset *asset = (PHAsset *)obj;
        NSLog(@"照片名%@", [asset
valueForKey:@"filename"]);
        [assets addObject:asset];
    }];
   // NSLog(@"%ld",assets.count);
    return assets;
}

- (void)didReceiveMemoryWarning {
    [super
didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

/*
#pragma mark - Navigation

// In a storyboard-based application, you will often want to do a little preparation before navigation
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
    // Get the new view controller using [segue destinationViewController].
    // Pass the selected object to the new view controller.
}
*/

@end