ISO7 二维码详细介绍及使用方法

 
// 1.创建过滤器
  cifilter *filter = [cifilter filterwithname:@"ciqrcodegenerator"];

  // 2.恢复默认
  [filter setdefaults];

  // 3.给过滤器添加数据(正则表达式/账号和密码)
  nsstring *datastring = @"http://www.520it.com";
  nsdata *data = [datastring datausingencoding:nsutf8stringencoding];
  [filter setvalue:data forkeypath:@"inputmessage"];

  // 4.获取输出的二维码
  ciimage *outputimage = [filter outputimage];

  //因为生成的二维码模糊，所以通过createnoninterpolateduiimageformciimage:outputimage来获得高清的二维码图片

  // 5.显示二维码
  self.imageview.image = [self createnoninterpolateduiimageformciimage:outputimage withsize:300];
 /**
 * 根据ciimage生成指定大小的uiimage
 *
 * @param image ciimage
 * @param size 图片宽度
 */
- (uiimage *)createnoninterpolateduiimageformciimage:(ciimage *)image withsize:(cgfloat) size
{
  cgrect extent = cgrectintegral(image.extent);
  cgfloat scale = min(size/cgrectgetwidth(extent), size/cgrectgetheight(extent));

  // 1.创建bitmap;
  size_t width = cgrectgetwidth(extent) * scale;
  size_t height = cgrectgetheight(extent) * scale;
  cgcolorspaceref cs = cgcolorspacecreatedevicegray();
  cgcontextref bitmapref = cgbitmapcontextcreate(nil, width, height, 8, 0, cs, (cgbitmapinfo)kcgimagealphanone);
  cicontext *context = [cicontext contextwithoptions:nil];
  cgimageref bitmapimage = [context createcgimage:image fromrect:extent];
  cgcontextsetinterpolationquality(bitmapref, kcginterpolationnone);
  cgcontextscalectm(bitmapref, scale, scale);
  cgcontextdrawimage(bitmapref, extent, bitmapimage);

  // 2.保存bitmap到图片
  cgimageref scaledimage = cgbitmapcontextcreateimage(bitmapref);
  cgcontextrelease(bitmapref);
  cgimagerelease(bitmapimage);
  return [uiimage imagewithcgimage:scaledimage];
}
 

 

// 1.创建捕捉会话
  avcapturesession *session = [[avcapturesession alloc] init];
  self.session = session;

  // 2.添加输入设备(数据从摄像头输入)
  avcapturedevice *device = [avcapturedevice defaultdevicewithmediatype:avmediatypevideo];
  avcapturedeviceinput *input = [avcapturedeviceinput deviceinputwithdevice:device error:nil];
  [session addinput:input];

  // 3.添加输出数据(示例对象-->类对象-->元类对象-->根元类对象)
  avcapturemetadataoutput *output = [[avcapturemetadataoutput alloc] init];
  [output setmetadataobjectsdelegate:self queue:dispatch_get_main_queue()];
  [session addoutput:output];

  // 3.1.设置输入元数据的类型(类型是二维码数据)
  [output setmetadataobjecttypes:@[avmetadataobjecttypeqrcode]];

  // 4.添加扫描图层
  avcapturevideopreviewlayer *layer = [avcapturevideopreviewlayer layerwithsession:session];
  layer.frame = self.view.bounds;
  [self.view.layer addsublayer:layer];
  self.layer = layer;

  // 5.开始扫描
  [session startrunning];
 

 

// 当扫描到数据时就会执行该方法
- (void)captureoutput:(avcaptureoutput *)captureoutput didoutputmetadataobjects:(nsarray *)metadataobjects fromconnection:(avcaptureconnection *)connection
{
  if (metadataobjects.count > 0) {
    //获得扫描数据，最后一个时最新扫描的数据
    avmetadatamachinereadablecodeobject *object = [metadataobjects lastobject];
    nslog(@"%@", object.stringvalue);

    // 停止扫描
    [self.session stoprunning];

    // 将预览图层移除
    [self.layer removefromsuperlayer];
  } else {
    nslog(@"没有扫描到数据");
  }
}