保存到相册的方法

//保存图片
- (IBAction)downLoadClick:(id)sender {
//   一、保存图片时候调用(保存到系统相册)
//    UIImageWriteToSavedPhotosAlbum(self.imageView.image, self, @selector(image:didFinishSavingWithError:contextInfo:), nil);
//   二、保存图片到自定义相册。photos框架  #import <Photos/Photos.h>
    /*
     PHAuthorizationStatusNotDetermined 不确定
     PHAuthorizationStatusRestricted 家长模式，拒绝
     PHAuthorizationStatusDenied, 拒绝
     PHAuthorizationStatusAuthorized 授权
     */
    
    PHAuthorizationStatus status = [PHPhotoLibrary authorizationStatus] ;
    
    if (status == PHAuthorizationStatusNotDetermined) { //不确定
        [PHPhotoLibrary requestAuthorization:^(PHAuthorizationStatus status) {
            if (status == PHAuthorizationStatusAuthorized) {
                 [self savePhoto] ;
            }
        }] ;
    }else if (status == PHAuthorizationStatusAuthorized){
        [self savePhoto] ;
    }else{
        //拒绝
        //提示用户去打开权限
        [SVProgressHUD showWithStatus:@"应用未打开权限，请去设置中打开权限！"] ;
    }
}

获取相册

//获取之前的相册
-(PHAssetCollection *)fetchAssetCollection:(NSString *)AlbumTitle {
    //获取之前的相册
    PHFetchResult *result = [PHAssetCollection fetchAssetCollectionsWithType:PHAssetCollectionTypeAlbum subtype:PHAssetCollectionSubtypeAlbumRegular options:nil] ;
    
    for (PHAssetCollection *assetCollection in result) {
        if ([assetCollection.localizedTitle isEqualToString:AlbumTitle]) {
            return assetCollection ;
        }
    }
    return nil ;
}

-(void)savePhoto{
//    二、保存图片到自定义相册。photos框架 <Photos/Photos.h>
    [[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{
        
        //判断之前有没有创建有没有去创建
        PHAssetCollection *assetCollection = [self fetchAssetCollection:@"百思不得姐"] ;
        PHAssetCollectionChangeRequest *assetCollectionChangeRequest ;
        if (assetCollection) {
            //已有相册
            assetCollectionChangeRequest = [PHAssetCollectionChangeRequest changeRequestForAssetCollection:assetCollection] ;
        }else{//没有相册
            //1.创建自定义相册assetCollectionChangeRequest           assetCollectionChangeRequest = [PHAssetCollectionChangeRequest creationRequestForAssetCollectionWithTitle:@"百思不得姐"] ;
        }
        
        
        //2.添加图片到系统相册
            PHAssetChangeRequest *assetChangeRequest = [PHAssetChangeRequest creationRequestForAssetFromImage:self.imageView.image] ;
            //3.拷贝图片到自定义相册（把图片的地址给自定义相册）
            PHObjectPlaceholder *placeholder = [assetChangeRequest placeholderForCreatedAsset] ;
            [assetCollectionChangeRequest addAssets:@[placeholder]] ;
 
    } completionHandler:^(BOOL success, NSError * _Nullable error) {
        if (error) {
            [SVProgressHUD showErrorWithStatus:@"保存失败！"];
        }else{
            [SVProgressHUD showSuccessWithStatus:@"保存成功"];
        }
    }] ;
}


 保存图片时候调用(保存到系统相册)

//- (void)image:(UIImage *)image didFinishSavingWithError:(NSError *)error contextInfo:(void *)contextInfo
//{
//
//    if (error) {
//
//        [SVProgressHUD showErrorWithStatus:@"保存失败！"];
//
//    }else{
//
//        [SVProgressHUD showSuccessWithStatus:@"保存成功"];
//
//    }
//}