AVCaptureMetadataOutput 的setRectOfInterest屬性來(lái)控制
CGRectMake(y的起點(diǎn)/屏幕的高鲸伴,x的起點(diǎn)/屏幕的寬伸头,掃描的區(qū)域的高/屏幕的高,掃描的區(qū)域的寬/屏幕的寬)
[_output setRectOfInterest:CGRectMake((124)/SCREEN_HEIGHT,0,SCREEN_WIDTH/SCREEN_HEIGHT,1)];
The default value of this property is the value CGRectMake(0, 0, 1, 1).