关于GestureRecognizer/Basic gestures的定义

UIGestureRecognizer:

Basic gestures:

Tap:

To start an application, simply tap the touchscreen with your finger on the relevant application icon; for example the Safari icon on the Home screen.

Double-Tap:

A quick double-tap of your finger has a special effect in different types of applications. For example in Safari, performing a double-tab (a single tap works too) over a username/password field on a particular web page will zoom-in on that portion of the page plus display the on-screen keyboard to assist you in filling in the form fields. A double-tap on a video or YouTube video enlarges the video while a second double-tap will restore or zoom-out the video to its original view.

Drag:

While reading an email or viewing the content of a webpage, you can slowly drag your finger across the screen either horizontally or vertically to scroll the text on-screen in your chosen direction.

Flick:

A flick is similar to a drag except you move your finger faster and lift your finger off the screen right after. The end result will be a scroll in the chosen direction only a lot faster.

Delete:

Here is a quick an easy way to delete items such as a video, song or email, use a flick (see above) except in a horizontal direction over the particular name of the item. This will reveal a red Delete button enabling you to remove the selected item. If you tap on the Delete button you will be given an opportunity to confirm. If you change your mind, either tap the cancel button (when asked to confirm), or tap anywhere other than on the red Delete button to cancel.

Pinch:

You use a pinch action to zoom in and out of a particular area of the screen. To perform a Pinch, place two fingers on the screen and spread them apart (to zoom in) or squeeze your fingers togeather (to zoom out). You may find that this is similar to a double-tap only the difference is that a Pinch gives you greater control. A video showing the Pinch gesture can be viewed in the video section at www.iphonegestures.com