原型单元格不能正确显示

Question

我的tableView有两个原型单元格，它们在故事板中编程如下。

标识符全部正确另一个不是IB与故事板之间的错误，因为标识符连接起来。但是当我建立并运行项目时，我会看到下面的屏幕（请注意，在这次运行中，semester.subjects和semester.activities是空的）。

另请注意，当我点击第一个单元格时，什么都没有发生，但是当我点击第二个单元格时，它会变成我想要的样子。我的问题是这是怎么发生的？如果你需要的话，下面是我的cellForRowAt indexPath。

override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell { 
    let cell = tableView.dequeueReusableCell(withIdentifier: "subjectCell", for: indexPath) as! SubjectTableViewCell 
    let addCell = tableView.dequeueReusableCell(withIdentifier: "addCell", for: indexPath) as! AddSubjectTableViewCell 
    var cellToAdd = UITableViewCell() 
    switch indexPath.section { 
    case 0: 
     if indexPath.row < semester.subjects.count{ 
     let subject = semester.subjects[indexPath.row] 
      cell.subjectColourView.backgroundColor = subject.colour 
      cell.subjectLabel.text = subject.name 
      cell.teacherLabel.text = subject.teacher 
     cellToAdd = cell 
     } 
     else if indexPath.row == semester.subjects.count { 
      cellToAdd = addCell 
     } 
    case 1: 
     if indexPath.row < semester.activities.count{ 
     let activity = semester.activities[indexPath.row] 
      cell.subjectColourView.backgroundColor = activity.colour 
      cell.subjectLabel.text = activity.name 
      cell.teacherLabel.text = activity.teacher 
     cellToAdd = cell 
     } 
     else if indexPath.row == semester.activities.count { 
      cellToAdd = addCell 
     } 

    default: 
     break 
    } 
    print(cellToAdd.reuseIdentifier) 
    return cellToAdd 


} 

这里是整个TVC

import UIKit 

类SubjectTableViewController：{的UITableViewController VAR 学期：学期！

override func viewDidLoad() { 
    super.viewDidLoad() 

    // 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 { 
    return 2 
} 

override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int { 
    switch section { 
    case 0: 
     return semester.subjects.count + 1 
    case 1: 
     return semester.activities.count + 1 
    default: 
     return 0 
    } 
} 
override func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? { 
    switch section { 
    case 0: 
     return "Subjects" 
    case 1: 
     return "Extracurricular Activities" 
    default: 
     return nil 
    } 
} 


override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell { 
    let cell = tableView.dequeueReusableCell(withIdentifier: "subjectCell", for: indexPath) as! SubjectTableViewCell 
    let addCell = tableView.dequeueReusableCell(withIdentifier: "addCell", for: indexPath) as! AddSubjectTableViewCell 
    var cellToAdd = UITableViewCell() 
    switch indexPath.section { 
    case 0: 
     if indexPath.row < semester.subjects.count{ 
     let subject = semester.subjects[indexPath.row] 
      cell.subjectColourView.backgroundColor = subject.colour 
      cell.subjectLabel.text = subject.name 
      cell.teacherLabel.text = subject.teacher 
     cellToAdd = cell 
     } 
     else if indexPath.row == semester.subjects.count { 
      cellToAdd = addCell 
     } 
    case 1: 
     if indexPath.row < semester.activities.count{ 
     let activity = semester.activities[indexPath.row] 
      cell.subjectColourView.backgroundColor = activity.colour 
      cell.subjectLabel.text = activity.name 
      cell.teacherLabel.text = activity.teacher 
     cellToAdd = cell 
     } 
     else if indexPath.row == semester.activities.count { 
      cellToAdd = addCell 
     } 

    default: 
     break 
    } 
    print(cellToAdd.reuseIdentifier) 
    return cellToAdd 


} 
} 

Answer 1

问题是，谁知道是什么原因，该单元在交换机之外被拒绝。

if indexPath.row < semester.subjects.count{ 
    let cell = tableView.dequeueReusableCell(withIdentifier: "subjectCell", for: indexPath) as! SubjectTableViewCell 
    let subject = semester.subjects[indexPath.row] 
     cell.subjectColourView.backgroundColor = subject.colour 
     cell.subjectLabel.text = subject.name 
     cell.teacherLabel.text = subject.teacher 
    cellToAdd = cell 
    }