Create a View You typically create a view in one of two ways: by initializing the view with a frame so that you can manually add the view to your UI, or by

Image View如何触发事件？ An image view isn’t a control, so it’s not designed to respond to input in the same way that a control—such as a button—responds. For example, you

ViewController View controllers implement your app’s behavior. A view controller manages a single content view with its hierarchy of subviews. View controllers coordinate the flow of information between the app’s data

在设置了Text Field的Constrain之后，在attribute inspector中还需要将Content Compression Resistance Priority的Intrinsic Size修改为“Placeholder”。官方解释是这样的： Text fields are sized based on their contents, which define their intrinsic content size. Intrinsic content size refers to the minimum size needed

Segue iOS中运行的应用拥有超过一个场景时，我们需要在不同场景之间进行切换，例如在主界面点击注册按钮即切换到到注册场景。场景之间的切换过程即为Segue。伴随着Segue的往往还会有数据交换。通过StoryBoard中的鼠标拖拽可以快速的建立场景间切换所需的Segue。 Unwind Segue 在新的场景中完成对应任务后，需要切换回原来的场景，并将新场景中的数据传递回去，这个过程即为Unwind Segue。在StoryBoard中右击触发切换的按钮并拖拽到Scene Dock中的Exit按钮，即可选择对应的Unwind方法。当然在此之前需要在对应的view controller中重写 prepareForSegue(_:)方法并对需要传递的数据做好准备，并实现具体的Unwind方法。

This style of app design where view controllers serve as the communication pipeline between your views and data model is known as MVC (Model-View-Controller). In this pattern, models keep track of your app’

Swift语言官方教程中，针对Delegate有这么一段描述： A delegate is an object that acts on behalf of, or in coordination with, another object. The delegating object—in this case, the text field—keeps a reference to the other

在Swift语言的官方教程中，这样描述Protocol： A protocol defines a blueprint of methods, properties, and other requirements that suit a particular task or piece of functionality. The protocol doesn’t actually provide an implementation for any of

花了一个周六的时间把作业1做完了。感觉自己智商真的不够用了。 operate，operation，operand傻傻分不清楚。