需要一个NFC读取的demo

//entryAbility 
function readerModeCb(err : BusinessError, tagInfo : tag.TagInfo) { 
  if (err as BusinessError) { 
    if (!err) { 
      console.log("offCallback: tag found tagInfo = ", JSON.stringify(tagInfo)); 
    } else { 
      console.error("offCallback err: " + (err as BusinessError).message); 
      return; 
    } 
  } 
  // other Operations of taginfo 
} 
 
export default class EntryAbility extends UIAbility { 
  ...... 
  onForeground() { 
    console.log("on start"); 
    try { 
      tag.on('readerMode', elementName, discTech, readerModeCb); 
    } catch (e) { 
      console.error("tag.on error: " + (e as BusinessError).message); 
    } 
  } 
 
  onBackground() { 
    console.log("onBackground"); 
    try { 
      tag.off('readerMode', elementName, readerModeCb); 
    } catch (e) { 
      console.error("tag.off error: " + (e as BusinessError).message); 
    } 
  } 
 
  onWindowStageDestroy() { 
    console.log("onWindowStageDestroy"); 
    try { 
      tag.off('readerMode', elementName, readerModeCb); 
    } catch (e) { 
      console.error("tag.off error: " + (e as BusinessError).message); 
    } 
  } 
}