使用Zbar来完成这一点。为了获得足够的分辨率来扫描，你会想在横向模式下扫描条形码。这里是我的设置（测试和工作）

// ADD: present a barcode reader that scans from the camera feed
ZBarReaderViewController *reader = [ZBarReaderViewController new];
reader.readerDelegate = self;
reader.supportedOrientationsMask = ZBarOrientationMaskAll;

ZBarImageScanner *scanner = reader.scanner;

//disable other codes to improve performance
[scanner setSymbology: 0
               config: ZBAR_CFG_ENABLE
                   to: 0];
[scanner setSymbology:ZBAR_CODE39 config:ZBAR_CFG_ENABLE to:1];
//only scan vertically, in the middle of the screen (also improves performance)
[reader setScanCrop:CGRectMake(0, 0.4, 1, 0.2)];
[reader setShowsZBarControls:NO];
[reader setShowsHelpOnFail:NO];
//VERY IMPORTANT: reset zoom. by default, the screen is partially zoomed in and will cause a loss of precision
reader.readerView.zoom = 1.0;
reader.readerView.allowsPinchZoom=NO;
reader.readerView.showsFPS=YES;
reader.readerView.tracksSymbols=YES;
//scan landscape only (this also improves performance)
[scanner setSymbology:ZBAR_CODE39 config:ZBAR_CFG_X_DENSITY to:0];
[scanner setSymbology:ZBAR_CODE39 config:ZBAR_CFG_Y_DENSITY to:1];

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差不多了！祝你好运！

• 编辑/注意：iOS框架现在包含了iOS 7的条形码扫描器。我使用this implementation获得了比使用Zbar更好更容易的结果。*