swift - 为什么我得到这个字符串值是 nil？

Question

基本上我正在尝试制作一个简单的笔记应用程序，在这里我只是尝试显示标题和内容。

项目(注释)文件

import Foundation

class Project
{
    var title = " "
    var content = " "
    var after = " "
}

注意细节 View Controller 文件

class NoteDetailViewController: UIViewController
{
    var project: Project!

    @IBOutlet weak var titleTextField: UITextField!
    @IBOutlet weak var contentTextField: UITextView!
    @IBOutlet weak var afterTextField: UITextView!

    override func viewWillAppear(animated: Bool)
    {
        super.viewWillAppear(animated)
        titleTextField.text = project.title
        contentTextField.text = project.content
        afterTextField.text = project.after

        contentTextField.sizeToFit()
        afterTextField.sizeToFit()
    }

    override func viewWillDisappear(animated: Bool)
    {
        super.viewWillDisappear(animated)

        project.title = titleTextField.text!
        project.content = contentTextField.text!
    }

}

当我引用任何项目时。文件，我得到零。我不知道为什么我从字符串中得到 nil？

Answer 1

您需要正确初始化“Project”类。

let project = Project()