4.UIViewController

UIViewController

UIViewController简单的说就是视图控制器, 用于view的管理, 数据的处理.

1. UIViewController的跳转(无导航栏)

利用前面学习的知识, 我们实现下面的需求:

ViewController中有一个UIButton, 点击UIButton跳转到ViewController2

ViewController2中也有一个UIButton, 点击UIButton返回到ViewController

ViewController的代码:

import UIKit

class ViewController: UIViewController {

override func viewDidLoad() {
super.viewDidLoad()

let button = UIButton(type: .Custom)
button.frame = CGRect(x: 0, y: 10, width: 100, height: 40)
// 设置不同状态文字
button.setTitle("Normal", forState: .Normal)
button.setTitle("Highlighted", forState: .Highlighted)
button.setTitle("Disabled", forState: .Disabled)
// 设置不同状态文字颜色
button.setTitleColor(UIColor.redColor(), forState: .Normal)
button.setTitleColor(UIColor.blueColor(), forState: .Highlighted)
button.setTitleColor(UIColor.grayColor(), forState: .Disabled)

button.setBackgroundImage(UIImage(named: "normal"), forState: .Normal)
button.setBackgroundImage(UIImage(named: "highlighted"), forState: .Highlighted)
button.setBackgroundImage(UIImage(named: "disabled"), forState: .Disabled)

button.addTarget(self, action: "buttonAction:", forControlEvents: .TouchUpInside)

self.view.addSubview(button)
}

func buttonAction(sender: UIButton) {
// 跳转到ViewController2
let vc = ViewController2()
self.presentViewController(vc, animated: true, completion: nil)
}

override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()

}

}

ViewController2代码:

import UIKit

class ViewController2: UIViewController {

override func viewDidLoad() {
super.viewDidLoad()

self.view.backgroundColor = UIColor(red: 0xff/255.0, green: 0x00/255.0, blue: 0xff/255.0, alpha: 1.0)

let button = UIButton(type: .Custom)
button.frame = CGRect(x: 0, y: 200, width: 100, height: 40)
// 设置不同状态文字
button.setTitle("返回", forState: .Normal)
button.setTitle("返回", forState: .Highlighted)
button.setTitle("返回", forState: .Disabled)
// 设置不同状态文字颜色
button.setTitleColor(UIColor.redColor(), forState: .Normal)
button.setTitleColor(UIColor.blueColor(), forState: .Highlighted)
button.setTitleColor(UIColor.grayColor(), forState: .Disabled)

button.setBackgroundImage(UIImage(named: "normal"), forState: .Normal)
button.setBackgroundImage(UIImage(named: "highlighted"), forState: .Highlighted)
button.setBackgroundImage(UIImage(named: "disabled"), forState: .Disabled)

button.addTarget(self, action: "backAction:", forControlEvents: .TouchUpInside)

self.view.addSubview(button)
}

func backAction(sender: UIButton) {
// 返回
self.dismissViewControllerAnimated(true, completion: nil)
}

override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}

}

我们看看实现的效果:



我们看看界面跳转的方法

public func presentViewController(viewControllerToPresent: UIViewController, animated flag: Bool, completion: (() -> Void)?)
第一个参数是要跳转的UIViewController
第二个参数是是否有动画
第三个参数是完成回调

界面返回方法

public func dismissViewControllerAnimated(flag: Bool, completion: (() -> Void)?)
第一个参数是否有动画
第二个参数是完成回掉

2. 界面跳转动画

self.modalTransitionStyle = .FlipHorizontal // 水平切换
self.modalTransitionStyle = .CoverVertical // 垂直切换
self.modalTransitionStyle = .CrossDissolve
self.modalTransitionStyle = .PartialCurl // 翻页

可以都试一下看看效果

3.UIViewController状态转换

public func viewWillAppear(animated: Bool) => UIViewController将出现调用

public func viewDidAppear(animated: Bool) =>UIViewController已出现调用

public func viewWillDisappear(animated: Bool) => UIViewController将消失调用

public func viewDidDisappear(animated: Bool) => UIViewController已消失调用

我们可以注意到,还有一个方法:

public func viewDidLoad() => 在第一次加载view时调用,只调用一次, 而上面的4个方法每次都会调用

我们重写上面的方法看看执行顺序, 修改ViewController2:

class ViewController2: UIViewController {

override func viewDidLoad() {
super.viewDidLoad()

print("viewDidLoad")

self.view.backgroundColor = UIColor(red: 0xff/255.0, green: 0x00/255.0, blue: 0xff/255.0, alpha: 1.0)

let button = UIButton(type: .Custom)
button.frame = CGRect(x: 0, y: 200, width: 100, height: 40)
// 设置不同状态文字
button.setTitle("返回", forState: .Normal)
button.setTitle("返回", forState: .Highlighted)
button.setTitle("返回", forState: .Disabled)
// 设置不同状态文字颜色
button.setTitleColor(UIColor.redColor(), forState: .Normal)
button.setTitleColor(UIColor.blueColor(), forState: .Highlighted)
button.setTitleColor(UIColor.grayColor(), forState: .Disabled)

button.setBackgroundImage(UIImage(named: "normal"), forState: .Normal)
button.setBackgroundImage(UIImage(named: "highlighted"), forState: .Highlighted)
button.setBackgroundImage(UIImage(named: "disabled"), forState: .Disabled)

button.addTarget(self, action: "backAction:", forControlEvents: .TouchUpInside)

self.view.addSubview(button)

self.modalTransitionStyle = .CrossDissolve
}

override func viewWillAppear(animated: Bool) {
super.viewWillAppear(animated)
print("viewWillAppear")
}

override func viewDidAppear(animated: Bool) {
super.viewDidAppear(animated)
print("viewDidAppear")
}

override func viewWillDisappear(animated: Bool) {
super.viewWillDisappear(animated)
print("viewDidAppear")
}

override func viewDidDisappear(animated: Bool) {
super.viewDidDisappear(animated)
print("viewDidDisappear")
}

func backAction(sender: UIButton) {
// 返回
self.dismissViewControllerAnimated(true, completion: nil)
}

override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}

}

运行程序,我们发现:

进入ViewController2的时候执行的方法依次是:

viewDidLoad => viewWillAppear => viewDidAppear

离开ViewController2的时候执行的方法依次是:

viewWillDisappear => viewDidDisappear

4. 界面间跳转传值

现在我们实现一个需求, ViewController跳转到ViewController2时,传一个年龄过去:

我们在ViewController2中添加一个age变量:

var age: Int?

然后在ViewController的跳转方法中赋值:

func buttonAction(sender: UIButton) {
// 跳转到ViewController2
let vc = ViewController2()
vc.age = 100
self.presentViewController(vc, animated: true, completion: nil)
}

最后在ViewController的viewDidLoad()中添加:

print("age=\(self.age!)")

运行程序我们发现,控制台中打印出:

5. 加载storyboard中的UIViewController

如果使用storyboard做界面, 虽然可以直接在两个UIViewController中拖线跳转, 但是有时候一个UIViewController根据条件跳转到不同的UIViewController, 这时候就需要用代码加载storyboard中的UIViewController,再根据条件来跳转.

在Main.storyboard中拖一个UIViewController,Storyboard ID设置为ViewControllerInSB

let mainStoryboard = UIStoryboard(name: "Main", bundle: NSBundle.mainBundle())
let vc = mainStoryboard.instantiateViewControllerWithIdentifier("ViewControllerInSB")
self.presentViewController(vc, animated: true, completion: nil)

6. 完整代码

ViewController.swift:

import UIKit

class ViewController: UIViewController {

override func viewDidLoad() {
super.viewDidLoad()

let button = UIButton(type: .Custom)
button.frame = CGRect(x: 0, y: 10, width: 100, height: 40)
// 设置不同状态文字
button.setTitle("Normal", forState: .Normal)
button.setTitle("Highlighted", forState: .Highlighted)
button.setTitle("Disabled", forState: .Disabled)
// 设置不同状态文字颜色
button.setTitleColor(UIColor.redColor(), forState: .Normal)
button.setTitleColor(UIColor.blueColor(), forState: .Highlighted)
button.setTitleColor(UIColor.grayColor(), forState: .Disabled)

button.setBackgroundImage(UIImage(named: "normal"), forState: .Normal)
button.setBackgroundImage(UIImage(named: "highlighted"), forState: .Highlighted)
button.setBackgroundImage(UIImage(named: "disabled"), forState: .Disabled)

button.addTarget(self, action: "buttonAction:", forControlEvents: .TouchUpInside)

self.modalTransitionStyle = .CrossDissolve
self.view.addSubview(button)
}

func buttonAction(sender: UIButton) {
// 跳转到ViewController2
let vc = ViewController2()
vc.age = 100
self.presentViewController(vc, animated: true, completion: nil)
}

override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()

}
}

ViewController2.swift:

class ViewController2: UIViewController {

var age: Int?

override func viewDidLoad() {
super.viewDidLoad()

print("viewDidLoad")
print("age=\(self.age!)")

self.view.backgroundColor = UIColor(red: 0xff/255.0, green: 0x00/255.0, blue: 0xff/255.0, alpha: 1.0)

let button = UIButton(type: .Custom)
button.frame = CGRect(x: 0, y: 200, width: 100, height: 40)
// 设置不同状态文字
button.setTitle("返回", forState: .Normal)
button.setTitle("返回", forState: .Highlighted)
button.setTitle("返回", forState: .Disabled)
// 设置不同状态文字颜色
button.setTitleColor(UIColor.redColor(), forState: .Normal)
button.setTitleColor(UIColor.blueColor(), forState: .Highlighted)
button.setTitleColor(UIColor.grayColor(), forState: .Disabled)

button.setBackgroundImage(UIImage(named: "normal"), forState: .Normal)
button.setBackgroundImage(UIImage(named: "highlighted"), forState: .Highlighted)
button.setBackgroundImage(UIImage(named: "disabled"), forState: .Disabled)

button.addTarget(self, action: "backAction:", forControlEvents: .TouchUpInside)

self.view.addSubview(button)

self.modalTransitionStyle = .CrossDissolve
}

override func viewWillAppear(animated: Bool) {
super.viewWillAppear(animated)
print("viewWillAppear")
}

override func viewDidAppear(animated: Bool) {
super.viewDidAppear(animated)
print("viewDidAppear")
}

override func viewWillDisappear(animated: Bool) {
super.viewWillDisappear(animated)
print("viewWillDisappear")
}

override func viewDidDisappear(animated: Bool) {
super.viewDidDisappear(animated)
print("viewDidDisappear")
}

func backAction(sender: UIButton) {
// 返回
self.dismissViewControllerAnimated(true, completion: nil)
}

override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}

}