I can not use sourceType as UIImagePickerControllerSourceTypePhotoLibrary in ZBarSDK

Question

I download ZBarSDK 1.2 in http://zbar.sourceforge.net/download.html It works well when I set the sourceType of ZBarReaderViewController as UIImagePickerControllerSourceTypeCamera. But when I set the sourceType as UIImagePickerControllerSourceTypePhotoLibrary or UIImagePickerControllerSourceTypeSavedPhotosAlbum,the app crashed and I got the error as follow:

2012-05-28 17:23:03.476 Wow[4137:10703] * Assertion failure in -[ZBarReaderViewController setSourceType:], /Users/spadix/zbar/hg/sdk/iphone/ZBarReaderViewController.m:650 2012-05-28 17:23:03.626 Wow[4137:10703] * Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'attempt to set unsupported value (1) for sourceType property'

I have google this issue but can't find a solution.Can anybody tell me how to solute this issue?Dose version 1.2 only support UIImagePickerControllerSourceTypeCamera?Dose the source witch I download is bad?

Thanks.

Answer 1

Basically present the standard iOS media view controller if you want to choose a saved image. After the user has selected an image from the standard iOS media controller, you instantiate a copy of ZBarImageScanner to scan the image. If this makes sense, skip to step 5 to see how I scan a UIImage using ZBarImageScanner. Otherwise, try and follow along the steps below. Hope this helps.

1. First show the user an alert with options.

   UIActionSheet *sheet = [[UIActionSheet alloc] initWithTitle:@"" delegate:self  
                                             cancelButtonTitle:@"Cancel" destructiveButtonTitle:nil otherButtonTitles:@"Camera", @"Camera   Roll", @"Photo Library", nil];
   [sheet showInView:self.view];
   

2. On selection,

   - (void)actionSheet:(UIActionSheet *)actionSheet willDismissWithButtonIndex:(NSInteger)buttonIndex {
       UIImagePickerControllerSourceType sourceType = UIImagePickerControllerSourceTypeSavedPhotosAlbum;
       switch (buttonIndex) {
           case 0: sourceType = UIImagePickerControllerSourceTypeCamera; break;
           case 1: sourceType = UIImagePickerControllerSourceTypeSavedPhotosAlbum; break;
           case 2: sourceType = UIImagePickerControllerSourceTypePhotoLibrary; break;
           default: break;
       }
       if ( buttonIndex <= 2 ) {
           [self presentBarcodeReader:sourceType];
       }
   }
   

3. if and only if the sourceType == UIImagePickerControllerSourceTypeCamera do you use ZBar to present the image capture interface.

   - (void)presentBarcodeReader:(UIImagePickerControllerSourceType)sourceType {
       if ( sourceType == UIImagePickerControllerSourceTypeCamera ) {
           ZBarReaderViewController *reader = [ZBarReaderViewController new];
           reader.readerDelegate = self;
           reader.showsZBarControls = YES;
           reader.supportedOrientationsMask = ZBarOrientationMaskAll;
   
           ZBarImageScanner *scanner = reader.scanner;
           [scanner setSymbology: ZBAR_I25
                          config: ZBAR_CFG_ENABLE
                              to: 0];
           [self presentModalViewController:reader animated:YES];
       } else {
           UIImagePickerController *mediaUI = [[UIImagePickerController alloc] init];
           mediaUI.sourceType = sourceType;
           mediaUI.mediaTypes = [UIImagePickerController         availableMediaTypesForSourceType:UIImagePickerControllerSourceTypeSavedPhotosAlbum];
           mediaUI.allowsEditing = NO;
           mediaUI.delegate = self;
           [self presentModalViewController:mediaUI animated:YES];
       }
   }
   

4. a couple ways we can detect which media picker was used

   - (void)imagePickerController:(UIImagePickerController*)reader didFinishPickingMediaWithInfo:(NSDictionary*)info {
       id<NSFastEnumeration> results = [info objectForKey: ZBarReaderControllerResults];
       if ( results ) {
           ZBarSymbol *symbol = nil;
           for (symbol in results) break;
   
           [reader dismissViewControllerAnimated:YES completion:^{
               [self partLookup:symbol.data];
           }];
       } else {
           UIImage *image = [info objectForKey:UIImagePickerControllerEditedImage] ?         [info objectForKey:UIImagePickerControllerEditedImage] : [info         objectForKey:UIImagePickerControllerOriginalImage];
           [self scanImage:image];
       }
   }
   

5. and the juicy part

   - (void)scanImage:(UIImage*)image {
       ZBarImage *zImage = [[ZBarImage alloc] initWithCGImage:image.CGImage];
       ZBarImageScanner *scanner = [[ZBarImageScanner alloc] init];
       [scanner setSymbology: ZBAR_I25
                      config: ZBAR_CFG_ENABLE
                          to: 0];
       [scanner scanImage:zImage];
       ZBarSymbolSet *set = [scanner results];
   
       for (ZBarSymbol *symbol in set) {
           NSLog(@"%@", symbol.data);
           // process symbol.data however you please.
       }
   }