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This article is about how to add views to iOS11 application code in iOS11 development. The editor thinks it is very practical, so share it with you as a reference and follow the editor to have a look.

What if the developer wants to add a view to the main view using the code. The following will solve this problem for developers. To add a view to the main view using code, you need to implement three steps.

(1) instantiate the view object

Each view is a specific class. In Swift, it is often said that a class is an abstract concept, not a concrete thing, so instantiate the class. The specific syntax for instantiating a view object is as follows:

Let/var object name = View Class ()

Take the first view we came into contact with, View, whose instantiated objects are as follows:

Let newView=UIView ()

Where UIView is the class of the blank view, and newView is an object instantiated by the UIView class.

(2) set the location and size of the view

Each view is an area, so you need to set the location and size for this area. Set the location and size property to frame, and its syntax is as follows:

Object name .frame = CGRect (x, y, width,height)

Where x and y represent the position of the view in the main view, and width and height represent the size of the view. The following sets the location and size for the instanced object newView:

NewView.frame=CGRect (x: 67, y: 264, width: 240, height: 128)

Where 67 and 264 represent the position in the main view of this view, and 240 and 128 represent the size of this view.

Note: steps 1 and 2 can also be merged. For example, the following code merges the instantiated object and the set location size of the UIView class:

Let newView=UIView (frame: CGRect (x: 67, y: 264, width: 240, height: 128))

(3) add a view to the current view

The last and most critical step is to add the instantiated object to the main view. Only in this way can it be displayed. At this point, you need to use the AddSubview () method, which has the following syntax:

This.view.addSubview (View object name)

The following adds the instantiated object newView to the current main view, with the following code:

Self.view.addSubview (newView)

[example 1-2] the following will use the code to add a View blank view in the primary view. The code is as follows:

Import UIKit

Class ViewController: UIViewController {

Override func viewDidLoad () {

Super.viewDidLoad ()

/ / Do any additional setup after loading the view, typically from a nib.

Let newView=UIView (frame: CGRect (x: 67, y: 264, width: 240, height: 128))

Self.view.addSubview (newView)

}

……

}

When you run the program at this point, you will see the effect shown in figure 1.50. The added view is also not visible in this run effect. This is because the added view has a white background by default, and if you want to see the view, you need to set its background. For example, the following code sets the background color to gray:

NewView.backgroundColor=UIColor.gray

When you run the program at this time, you will see the effect shown in figure 1.51.

Figure 1.50 running effect figure 1.51 running effect

Thank you for reading! This is the end of this article on "how to add views to iOS11 application code in iOS11 development". I hope the above content can be of some help to you, so that you can learn more knowledge. if you think the article is good, you can share it out for more people to see!

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