ios开发多选照片实现

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

@interface ViewController () <UIImagePickerControllerDelegate, UINavigationControllerDelegate>
@property (weak, nonatomic) IBOutlet UIImageView *imageView;
@end

@implementation ViewController

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

- (IBAction)selectImage {
    [self getThumbnailImages];
}

/**
 *  获得所有相簿的原图
 */
- (void)getOriginalImages
{
    // 获得所有的自定义相簿
    PHFetchResult<PHAssetCollection *> *assetCollections = [PHAssetCollection fetchAssetCollectionsWithType:PHAssetCollectionTypeAlbum subtype:PHAssetCollectionSubtypeAlbumRegular options:nil];
    // 遍历所有的自定义相簿
    for (PHAssetCollection *assetCollection in assetCollections) {
        [self enumerateAssetsInAssetCollection:assetCollection original:YES];
    }
    
    // 获得相机胶卷
    PHAssetCollection *cameraRoll = [PHAssetCollection fetchAssetCollectionsWithType:PHAssetCollectionTypeSmartAlbum subtype:PHAssetCollectionSubtypeSmartAlbumUserLibrary options:nil].lastObject;
    [self enumerateAssetsInAssetCollection:cameraRoll original:YES];
}

/**
 *  获得所有相簿中的缩略图
 */
- (void)getThumbnailImages
{
    // 获得所有的自定义相簿
    PHFetchResult<PHAssetCollection *> *assetCollections = [PHAssetCollection fetchAssetCollectionsWithType:PHAssetCollectionTypeAlbum subtype:PHAssetCollectionSubtypeAlbumRegular options:nil];
    // 遍历所有的自定义相簿
    for (PHAssetCollection *assetCollection in assetCollections) {
        [self enumerateAssetsInAssetCollection:assetCollection original:NO];
    }
    
    // 获得相机胶卷
    PHAssetCollection *cameraRoll = [PHAssetCollection fetchAssetCollectionsWithType:PHAssetCollectionTypeSmartAlbum subtype:PHAssetCollectionSubtypeSmartAlbumUserLibrary options:nil].lastObject;
    [self enumerateAssetsInAssetCollection:cameraRoll original:NO];
}

/**
 *  遍历相簿中的所有图片
 *
 *  @param assetCollection 相簿
 *  @param original        是否要原图
 */
- (void)enumerateAssetsInAssetCollection:(PHAssetCollection *)assetCollection original:(BOOL)original
{
    NSLog(@"相簿名:%@", assetCollection.localizedTitle);
    
    PHImageRequestOptions *options = [[PHImageRequestOptions alloc] init];
    // 同步获得图片, 只会返回1张图片
    options.synchronous = YES;

    // 获得某个相簿中的所有PHAsset对象
    PHFetchResult<PHAsset *> *assets = [PHAsset fetchAssetsInAssetCollection:assetCollection options:nil];
    for (PHAsset *asset in assets) {
        // 是否要原图
        CGSize size = original ? CGSizeMake(asset.pixelWidth, asset.pixelHeight) : CGSizeZero;
        
        // 从asset中获得图片
        [[PHImageManager defaultManager] requestImageForAsset:asset targetSize:size contentMode:PHImageContentModeDefault options:options resultHandler:^(UIImage * _Nullable result, NSDictionary * _Nullable info) {
            NSLog(@"%@", result);
        }];
    }
}

/**
 *  获得相机胶卷中的所有图片
 */
- (void)getImagesFromCameraRoll
{
    // 获得相机胶卷中的所有图片
    PHFetchResult<PHAsset *> *assets = [PHAsset fetchAssetsWithOptions:nil];
    
    __block int count = 0;
    
    for (PHAsset *asset in assets) {
        [[PHImageManager defaultManager] requestImageForAsset:asset targetSize:CGSizeMake(asset.pixelWidth, asset.pixelHeight) contentMode:PHImageContentModeDefault options:nil resultHandler:^(UIImage * _Nullable result, NSDictionary * _Nullable info) {
            NSLog(@"%@ - %zd", result, count++);
        }];
    }
}

/**
 *  利用UIImagePickerController挑选图片
 */
- (void)getImageFromIpc
{
    // UIImagePickerController : 可以从系统自带的App(照片\相机)中获得图片

    // 判断相册是否可以打开
    if (![UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypePhotoLibrary]) return;

    UIImagePickerController *ipc = [[UIImagePickerController alloc] init];
    // 打开照片应用(显示所有相簿)
    ipc.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
    // 打开照片应用(只显示"时刻"这个相簿)
    // ipc.sourceType = UIImagePickerControllerSourceTypeSavedPhotosAlbum;
    // 照相机
    // ipc.sourceType = UIImagePickerControllerSourceTypeCamera;
    ipc.delegate = self;
    [self presentViewController:ipc animated:YES completion:nil];
}

#pragma mark - <UIImagePickerControllerDelegate>
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary<NSString *,id> *)info
{
    // 销毁控制器
    [picker dismissViewControllerAnimated:YES completion:nil];

    // 设置图片
    self.imageView.image = info[UIImagePickerControllerOriginalImage];
}

@end