iOS Sample code for selecting multiple photos from a system album

I have written UIImagePickerController to retrieve the system photo album pictures before (select a single photo, which is mostly used for the user's avatar)

1. pod import

pod 'CTAssetsPickerController'

2. Add a header file

#import <CTAssetsPickerController/CTAssetsPickerController.h>

3. Add delegate

<CTAssetsPickerControllerDelegate>

4. Implement

- (void)upLoading {
  [PHPhotoLibraryrequestAuthorization:^(PHAuthorizationStatus status){
    if (status !=PHAuthorizationStatusAuthorized)return;
    dispatch_async(dispatch_get_main_queue(), ^{
      CTAssetsPickerController *picker = [[CTAssetsPickerControlleralloc] init];
      picker.delegate =self;
      //  Displays the selected index 
      picker.showsSelectionIndex =YES;
      //  Set the type of photo album: camera film  + Custom album 
      picker.assetCollectionSubtypes =@[
                        @(PHAssetCollectionSubtypeSmartAlbumUserLibrary),
                        @(PHAssetCollectionSubtypeAlbumRegular)];
      //  No need to display empty albums 
      picker.showsEmptyAlbums =NO;
      [selfpresentViewController:pickeranimated:YEScompletion:nil];
    });
  }];
}

-(BOOL)assetsPickerController:(CTAssetsPickerController *)picker shouldSelectAsset:(PHAsset *)asset
{
  NSInteger max =9;
  if (picker.selectedAssets.count >= max) {
    UIAlertController *alert = [UIAlertControlleralertControllerWithTitle:@" Prompt "message:[NSStringstringWithFormat:@" Maximum choice %zd A picture ", max] preferredStyle:UIAlertControllerStyleAlert];
    [alert addAction:[UIAlertActionactionWithTitle:@" OK "style:UIAlertActionStyleDefaulthandler:nil]];
    [picker presentViewController:alertanimated:YEScompletion:nil];
    //  You can't use it here self Come modal Other controllers, because at this time self.view Not in window Upper 
    returnNO;
  }
  returnYES;
}

-(void)assetsPickerController:(CTAssetsPickerController *)picker didFinishPickingAssets:(NSArray *)assets
{
  
  NSArray *array =NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask,YES);
  NSString *documents = [arraylastObject];
  NSString *documentPath = [documentsstringByAppendingPathComponent:@"arrayXML.xml"];
  
  NSArray *dataArray = [NSArrayarrayWithArray:assets];
  
  
  [dataArray writeToFile:documentPathatomically:YES];
  
  
  
  NSArray *resultArray = [NSArrayarrayWithContentsOfFile:documentPath];
  NSLog(@"%@", documentPath);
  
  
  //  Close the picture selection interface 
  [picker dismissViewControllerAnimated:YEScompletion:nil];
  
  //  Traverse through all selected pictures 
  self.plCollection.photoArray = assets;
  for (NSInteger i =0; i < assets.count; i++) {
    //  Basic configuration 
    CGFloat scale = [UIScreenmainScreen].scale;
    PHImageRequestOptions *options = [[PHImageRequestOptionsalloc] init];
    options.resizeMode  =PHImageRequestOptionsResizeModeExact;
    options.deliveryMode =PHImageRequestOptionsDeliveryModeHighQualityFormat;
    
    PHAsset *asset = assets[i];
    CGSize size =CGSizeMake(asset.pixelWidth / scale, asset.pixelHeight / scale);
//    //  Get a picture 
    [[PHImageManagerdefaultManager] requestImageForAsset:assettargetSize:size contentMode:PHImageContentModeDefaultoptions:options resultHandler:^(UIImage *_Nullable result,NSDictionary *_Nullable info) {
      NSData *imageData =UIImageJPEGRepresentation([selfimageWithImageSimple:resultscaledToSize:CGSizeMake(200,200)], 0.5);
      [selfossUpload:imageData];

    }];
  }
}