你们怎么能告诉一下UIPrint InteractionController是否正在显示?
原文：How can you tell if a UIPrintInteractionController is showing?

Is there a way to tell if a UIPrintInteractionController is showing (maybe similar to the way you would check a popover)? if ([popover isPopoverVisible]) { //the popover is visible }

页: 1 印刷工作失败
原文：iPhone 4.2 airprint Print job fails

不管印刷商I选择什么,我“Print-job失败:无佐证文件格式“申请/pdf”。