ios - 应用程序不在标签上显示 var 字符串

Question

我正在尝试制作一个应用程序，它可以获取学生姓名和总分(满分 1000 分)，并在按下按钮时将其显示在标签上。显示的公式是“x 学生获得 y 成绩”。由于某种原因(我不确定)我已经连接了 Storyboard并且代码看起来是正确的；标签不显示字符串。相反，它给了我类似的东西:

“可选(UITextField:0x7ff6696095550;框架=”等，等等

如果有人可以查看我的代码并帮助我如何让该字符串显示在标签上 - 我将非常感激。

    import UIKit

class ViewController: UIViewController {

    @IBOutlet weak var gradeTF: UITextField!
    @IBOutlet weak var nameGR: UITextField!
    @IBOutlet var label1 : UILabel!


    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
    }



    @IBAction func submitTapped(_ sender: UIButton) {

        var gradeMS = ""

        if (gradeTF.text?.isEmpty)! {

            gradeMS = "Please enter point total"

        }
        else {
            let grade : Int = Int(gradeTF.text!)!


            if grade > 1000 {
                gradeMS = "ERROR - Invalid point total"
                label1.text = gradeMS
            }
            else if grade > 900 && grade <= 1000 {
                gradeMS = "\(nameGR)'s grade is \"A\""
                label1.text = gradeMS
            }
            else if grade > 800 && grade <= 900 {
                gradeMS = "\(nameGR)'s grade is \"B\""
                label1.text = gradeMS
            }
            else if grade > 700 && grade <= 800 {
                gradeMS = "\(nameGR)'s grade is \"C\""
                label1.text = gradeMS
            }
            else if grade > 600 && grade <= 700 {
                gradeMS = "\(nameGR)'s grade is \"D\""
                label1.text = gradeMS
            }
            else {
                gradeMS = "\(nameGR)'s grade is \"F\""
                label1.text = gradeMS
            }
            }


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


    }

}

Answer 1

您应该使用 nameGR 文本字段中的文本，而不是文本字段本身。

替换

gradeMS = "\(nameGR)'s grade is \"A\""

与

gradeMS = "\(nameGR.text!)'s grade is \"A\""

submitTapped IBAction 中的所有位置。

@IBAction func submitTapped(_ sender: UIButton) {

    var gradeMS = ""
    let name = nameGR.text

    if (gradeTF.text?.isEmpty)! {

        gradeMS = "Please enter point total"

    }
    else {
        let grade : Int = Int(gradeTF.text!)!


        if grade > 1000 {
            gradeMS = "ERROR - Invalid point total"
            label1.text = gradeMS
        }
        else if grade > 900 && grade <= 1000 {
            gradeMS = name! + "'s grade is \"A\""
            label1.text = gradeMS
        }
        else if grade > 800 && grade <= 900 {
            gradeMS = name! + "'s grade is \"B\""
            label1.text = gradeMS
        }
        else if grade > 700 && grade <= 800 {
            gradeMS = name! + "'s grade is \"C\""
            label1.text = gradeMS
        }
        else if grade > 600 && grade <= 700 {
            gradeMS = name! + "'s grade is \"D\""
            label1.text = gradeMS
        }
        else {
            gradeMS = name! + "'s grade is \"F\""
            label1.text = gradeMS
        }
    }
}