Mid-air gestures have been largely overlooked for transferring contents among multiple screens. For verification, a cross-screen interfaces sharing system is designed, which enables users to move interface content across screens by gestures in real time. According to the user-designed gesture survey, two mid-air gestures, "grab-drag" and "grab-pull-drop", are implemented. User experiment shows that they are novel, useful, and easy to learn. In general, "grab-drag" provides better user experience, while "grab-pull-drop" is more versatile in complex scenarios. The former gesture is more suitable when the two screens are adjacent and the operation distance is short too; while the latter suits are better in away-from-screen scenarios, when there is a third screen among target screens or screens are widely spaced. Therefore, a combination of the two gestures will be a rational solution.