IOS开发之页面跳转

页面跳转需要添加navigationController,方法是在storyBoard视图中点击一个启动视图，点击右下角的 Embed in 按钮即可添加一个navigationController

 接下来在视图界面中的按钮 按住Ctrl 拖动指向另外一个界面，在弹窗中选择 show 既可以跳转对应的目标页面。

如果一个页面有多个按钮需要跳转页面，需要在类中判断是否可以跳转，重写方法shouldPerformSegue，该方法控制是否可以跳转页面：

还有一个方法是prepare,方法，是等待shouldPerformSegue返回true的时候紧接着调用，下面的例子演示冲登录页面跳转到登录成功界面（跳转需要用户名和密码不为nil）和注册页面（跳转不需要条件）

loginVC:

 
 
import UIKit
 
/**
 
 登录界面
 
 */
class LoginVC: UIViewController {
 
    @IBOutlet weak var errorTip: UILabel!
    @IBOutlet weak var password: UITextField!
    @IBOutlet weak var username: UITextField!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view.
    }
    
    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        if segue.identifier == "loginSuccess" {
            let target = segue.destination as? SuccessVC;
            target?.text = "登录成功"
        }
    }
    // 是否决定进行页面跳转
    override func shouldPerformSegue(withIdentifier identifier: String, sender: Any?) -> Bool {
        if(identifier == "register") {
            return true;
        } else {
//            let usernameIsOk = username.text ?? "";
            //username.text?.isEmpty
            if username.hasText && password.hasText {
                errorTip.text = "";
                return true;
            }
            if !username.hasText {
                errorTip.text = "用户名不能为空！"
                return false;
            }
            if !password.hasText {
                errorTip.text = "请输入密码！"
                return false;
            }
            return false;
        }
        
    }
 
 
}
 

successVC:

 
 
import UIKit
 
class SuccessVC: UIViewController {
 
    var text: String = ""
    @IBOutlet weak var successLabel: UILabel!
    
    @IBOutlet weak var backButton: UIButton!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        successLabel.text = text;
        // Do any additional setup after loading the view.
    }
    
 
    @IBAction func backEvent(_ sender: UIButton) {
//        self.navigationController?.popViewController(animated: true)
        // 退出页面调用dismiss方法退出当前视图
        self.dismiss(animated: true) {
            print("退出成功");
        }
    }
    /*
    // MARK: - Navigation
    // In a storyboard-based application, you will often want to do a little preparation before navigation
    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        // Get the new view controller using segue.destination.
        // Pass the selected object to the new view controller.
    }
    */
 
}