文章内容来源于Apple的开发者文档：https://developer.apple.com/library/content/documentation/UserExperience/Conceptual/Adopting3DTouchOniPhone/，这个文档中还提供了几个示例，建议直接阅读该文档。
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iOS 9中以后，引入了3D Touch功能。主要包括两个方面，一是Home Screen Quick Actions, 二是Peek and Pop。
Home Screen Quick Actions
实现这个主要有两种方式，
- 在Info.plist中的UIApplicationShortcutIconTypeAdd下定义静态的quick actions；
- 动态的定义，使用UIApplicationShortItem及相关的API定义quick action，添加到UIApplication对象的shortcutItems属性。
这里主要说一下第一种方式中各property的含义,先来看一个示例：
1 <key>UIApplicationShortcutItems</key> 2 <array> 3 <dict> 4 <key>UIApplicationShortcutItemIconFile</key> 5 <string>open-favorites</string> 6 <key>UIApplicationShortcutItemTitle</key> 7 <string>Favorites</string> 8 <key>UIApplicationShortcutItemType</key> 9 <string>com.mycompany.myapp.openfavorites</string> 10 <key>UIApplicationShortcutItemUserInfo</key> 11 <dict> 12 <key>key1</key> 13 <string>value1</string> 14 </dict> 15 </dict> 16 <dict> 17 <key>UIApplicationShortcutItemIconType</key> 18 <string>UIApplicationShortcutIconTypeCompose</string> 19 <key>UIApplicationShortcutItemTitle</key> 20 <string>New Message</string> 21 <key>UIApplicationShortcutItemType</key> 22 <string>com.mycompany.myapp.newmessage</string> 23 <key>UIApplicationShortcutItemUserInfo</key> 24 <dict> 25 <key>key2</key> 26 <string>value2</string> 27 </dict> 28 </dict> 29 </array>
各个key的解释：
Peek and Pop
可以在view controller中响应用户不同力度的按压。交互处理过程(还是按Apple的原文吧，翻译的表达不太好，原文也很简单)：
- Indication that content preview is available.
- Display of the preview ---- known as a peek ---- with options to act on it directly ---- known as peek quick actions
- Optional navigation to the view shown in the preview ---- known as a pop