photolibrary - 我无法在 ZBarSDK 中使用 sourceType 作为 UIImagePickerControllerSourceTypePhotoLibrary

Question

我在http://zbar.sourceforge.net/download.html下载ZBarSDK 1.2 当我将 ZBarReaderViewController 的 sourceType 设置为 UIImagePickerControllerSourceTypeCamera 时效果很好。 但是当我将 sourceType 设置为 UIImagePickerControllerSourceTypePhotoLibrary 或 UIImagePickerControllerSourceTypeSavedPhotosAlbum 时，应用程序崩溃并收到如下错误:

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'

我google了这个问题，但找不到解决方案。有人可以告诉我如何解决这个问题吗？1.2版本只支持UIImagePickerControllerSourceTypeCamera吗？我下载的源代码是否有问题？

谢谢。

Answer 1

如果你想选择保存的图像，基本上呈现标准的 iOS 媒体 View Controller 。用户从标准 iOS 媒体 Controller 选择图像后，您可以实例化 ZBarImageScanner 的副本来扫描图像。如果这是有意义的，请跳到步骤 5 以了解如何使用 ZBarImageScanner 扫描 UIImage。否则，请尝试按照以下步骤操作。希望这会有所帮助。

1. 首先向用户显示带有选项的警报。

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

2. 选择时，

   - (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. 当且仅当sourceType == UIImagePickerControllerSourceTypeCamera时，才使用ZBar呈现图像采集界面。

   - (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. 我们可以通过几种方法来检测使用了哪个媒体选择器

   - (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. 还有多汁的部分

   - (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.
       }
   }