navigationが動作しなくなる

Question

前提・実現したいこと

UITextFieldに余白を入れた実装をしたのですが、なぜかnavigationItem.rightBarButtonItemが機能しなくなります。

環境

• Swift4
• xcode9.3

発生している問題・エラーメッセージ

class TableViewController: UITableViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        
        navigationItem.title = "Todo"
        navigationItem.rightBarButtonItem = UIBarButtonItem(title: "Add", style: .plain, target: self, action: #selector(self.addTodo))

        // Uncomment the following line to preserve selection between presentations
        // self.clearsSelectionOnViewWillAppear = false

        // Uncomment the following line to display an Edit button in the navigation bar for this view controller.
        // self.navigationItem.rightBarButtonItem = self.editButtonItem
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    // MARK: - Table view data source

    override func numberOfSections(in tableView: UITableView) -> Int {
        // #warning Incomplete implementation, return the number of sections
        return 0
    }

    override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        // #warning Incomplete implementation, return the number of rows
        return 0
    }
    
    // MARK: objces
    @objc func addTodo(){
        let c = AddViewController()
        navigationController?.pushViewController(c, animated: true)
    }

}

以下のソースが問題のコードです。

class AddViewController: UIViewController {
    
    let label = UILabel()
    let titleField = UITextField()
    let bodyField = UITextField()
    let btn = UIButton()
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        let viewWidth = self.view.bounds.width
        let viewHeight = self.view.bounds.height
        let paddingView = UIView(frame: CGRect(x: 0, y: 0, width: 10, height: 5))
        paddingView.backgroundColor = UIColor.clear
        
        label.frame = CGRect(x: viewWidth / 4, y: viewHeight / 2 - 50, width: viewWidth / 2, height: 30)
        label.text = "Add your Todo"
        label.textAlignment = .center
        self.view.addSubview(label)
        
        titleField.frame = CGRect(x: 20, y: viewHeight / 2, width: viewWidth - 40, height: 30)
        titleField.placeholder = "title"
        titleField.layer.borderWidth = 0.5
        titleField.leftView = paddingView
        titleField.leftViewMode = .always
        self.view.addSubview(titleField)
        
        bodyField.frame = CGRect(x: 20, y: viewHeight / 2 + 50, width: viewWidth - 40, height: 30)
        bodyField.placeholder = "body"
        bodyField.layer.borderWidth = 0.5
        bodyField.leftView = paddingView
        //以下のコメントアウトを外すとnavigationItemが動作しなくなる
        //bodyField.leftViewMode = .always
        self.view.addSubview(bodyField)
    }

}

ご助言頂けますと幸いです。

Answer 1

それぞれのtextFieldに別々のpaddingViewを設定するとうまく行きました。

class AddViewController: UIViewController {
    
    let label = UILabel()
    let titleField = UITextField()
    let bodyField = UITextField()
    let btn = UIButton()
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        let viewWidth = self.view.bounds.width
        let viewHeight = self.view.bounds.height
        let paddingView = UIView(frame: CGRect(x: 0, y: 0, width: 10, height: 5))
        paddingView.backgroundColor = UIColor.clear

        // paddingViewをもう一つ用意する
        let paddingView2 = UIView(frame: CGRect(x: 0, y: 0, width: 10, height: 5))
        paddingView2.backgroundColor = UIColor.clear


        label.frame = CGRect(x: viewWidth / 4, y: viewHeight / 2 - 50, width: viewWidth / 2, height: 30)
        label.text = "Add your Todo"
        label.textAlignment = .center
        self.view.addSubview(label)
        
        titleField.frame = CGRect(x: 20, y: viewHeight / 2, width: viewWidth - 40, height: 30)
        titleField.placeholder = "title"
        titleField.layer.borderWidth = 0.5
        titleField.leftView = paddingView
        titleField.leftViewMode = .always
        self.view.addSubview(titleField)
        
        bodyField.frame = CGRect(x: 20, y: viewHeight / 2 + 50, width: viewWidth - 40, height: 30)
        bodyField.placeholder = "body"
        bodyField.layer.borderWidth = 0.5

        // paddingView2を設定する
        bodyField.leftView = paddingView2


        bodyField.leftViewMode = .always
        self.view.addSubview(bodyField)
    }
    
}

参考記事
https://stackoverflow.com/questions/31422247/issue-with-uitextfields-leftview-property

【追記】

extension UIView
{
    func copyView<T: UIView>() -> T {
        return NSKeyedUnarchiver.unarchiveObject(with: NSKeyedArchiver.archivedData(withRootObject: self)) as! T
    }
}

bodyField.leftView = paddingView.copyView()

Comments

[kenny_sayama]

回答いただきありがとうございます。
別のpaddingViewを用意するという方法で自分も実装してしまったのですが、使い回しが出来ないものかと悩んでおります...

[newmt]

一応UIVIewをコピーするという方法もありましたので追記しました。あまり変わらないのかもしれませんが。
参考記事: https://stackoverflow.com/questions/27121655/create-a-copy-of-a-uiview-in-swift