从Swift中的函数设置UiButton的状态

问题描述：

我有7个按钮可以在一周内打开和关闭几天。如果，例如，星期日的按钮被按下，一个IBAction为自动切换的状态没有任何问题：从Swift中的函数设置UiButton的状态

@IBAction func SoToggle(_ sender: UIButton) { 
    self.So.isSelected = !self.So.isSelected; 
}

但是，当我试图从一个函数在同一个类中设置该按钮的状态，我得到一个错误说：

unexpectedly found nil while unwrapping an Optional value

下面是用于“isSelected”设置为代码true或false：

func setSo(state: Bool) { 
    self.So.isSelected = state 
}

我不明白为什么这是行不通的，因为它是预很多相同的代码。

编辑：该函数由TableViewController调用，并且按钮位于自定义的TableViewCell中。我包括了整个代码，只是为了说清楚。 TableViewController：

class TableViewSettings: UITableViewController{ 

let sections = ["weekdays", "start time"] 

var CellDays:TableViewCellDays = TableViewCellDays() 
override func viewDidLoad() { 
    super.viewDidLoad() 

    self.view.layer.cornerRadius = 7 

    self.tableView.contentInset = UIEdgeInsets(top: 10,left: 0,bottom: 0,right: 0) 

    // 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 tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? { 
    return self.sections[section] 
} 

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

override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int { 
    // #warning Incomplete implementation, return the number of rows 
    return 1 
} 


override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell { 
    if(indexPath.section == 0) { 
     return Bundle.main.loadNibNamed("TableViewCellDays", owner: self, options: nil)?.first as! TableViewCellDays 
    } else { 
     return Bundle.main.loadNibNamed("TableViewCellPicker", owner: self, options: nil)?.first as! TableViewCellPicker 
    } 
} 

override func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat { 
    if(indexPath.section == 0) { 
     return 80 
    } else { 
     return 150 
    } 
} 


override func tableView(_ tableView: UITableView, heightForFooterInSection section: Int) -> CGFloat { 
    return 15 
} 

override func tableView(_ tableView: UITableView, heightForHeaderInSection section: Int) -> CGFloat { 
    return 30 
} 

override func tableView(_ tableView: UITableView, viewForFooterInSection section: Int) -> UIView? { 
    let v: UIView = UIView() 
    v.backgroundColor = .clear 
    return v; 
} 

override func tableView(_ tableView: UITableView, viewForHeaderInSection section: Int) -> UIView? { 
    let cell = Bundle.main.loadNibNamed("TableViewCellHeader", owner: self, options: nil)?.first as! TableViewCellHeader 

    cell.mainLabel.text = sections[section] 

    return cell 
} 

func setSettingsButtons(settings: [String]) { 
//  if (settings[0] == "1") { 
//   CellDays.Mo.isSelected = true 
//  } else {CellDays.Mo.isSelected = false} 
//   
//  if (settings[1] == "1") { 
//   CellDays.Di.isSelected = true 
//  } else {CellDays.Di.isSelected = false} 
//   
//  if (settings[2] == "1") { 
//   CellDays.Mi.isSelected = true 
//  } else {CellDays.Mi.isSelected = false} 
//   
//  if (settings[3] == "1") { 
//   CellDays.Do.isSelected = true 
//  } else {CellDays.Do.isSelected = false} 
//   
//  if (settings[4] == "1") { 
//   CellDays.Fr.isSelected = true 
//  } else {CellDays.Fr.isSelected = false} 
//   
//  if (settings[5] == "1") { 
//   CellDays.Sa.isSelected = true 
//  } else {CellDays.Sa.isSelected = false} 
//   
//  if (settings[6] == "1") { 
//   CellDays.So.isSelected = true 
//  } else {CellDays.So.isSelected = false} 

    CellDays.setSo(state: true) 
}

TableViewCell：

class TableViewCellDays: UITableViewCell { 

@IBOutlet var Mo: UIButton! 
@IBOutlet var Di: UIButton! 
@IBOutlet var Mi: UIButton! 
@IBOutlet var Do: UIButton! 
@IBOutlet var Fr: UIButton! 
@IBOutlet var Sa: UIButton! 
@IBOutlet var So: UIButton! 

@IBOutlet var MoLeading: NSLayoutConstraint! 
@IBOutlet var DiLeading: NSLayoutConstraint! 
@IBOutlet var MiLeading: NSLayoutConstraint! 
@IBOutlet var DoLeading: NSLayoutConstraint! 
@IBOutlet var FrLeading: NSLayoutConstraint! 
@IBOutlet var SaLeading: NSLayoutConstraint! 
@IBOutlet var SoLeading: NSLayoutConstraint! 



var offset: CGFloat = 10 

override func awakeFromNib() { 
    super.awakeFromNib() 

    // init Button states 

    Mo.isSelected = false 
    Di.isSelected = false 
    Mi.isSelected = false 
    Do.isSelected = false 
    Fr.isSelected = false 
    Sa.isSelected = false 
    So.isSelected = false 


    let screenWidth = UIScreen.main.bounds.width 
    let screenWidthCenter = screenWidth/2 
    let frameWidth = Do.frame.width 

    // Offset Settings depending on Device 

    offset = screenWidth/37 

    print(offset) 


    // X Coordinate Settings 

    MoLeading.constant = screenWidthCenter - 3.5 * frameWidth - 3.75 * offset 
    DiLeading.constant = screenWidthCenter - 2.5 * frameWidth - 2.75 * offset 
    MiLeading.constant = screenWidthCenter - 1.5 * frameWidth - 1.75 * offset 
    DoLeading.constant = screenWidthCenter - 0.5 * frameWidth - 0.75 * offset 
    FrLeading.constant = screenWidthCenter + 0.5 * frameWidth + 0.25 * offset 
    SaLeading.constant = screenWidthCenter + 1.5 * frameWidth + 1.25 * offset 
    SoLeading.constant = screenWidthCenter + 2.5 * frameWidth + 2.25 * offset 



} 

@IBAction func MoToggle(_ sender: UIButton) { 
    self.Mo.isSelected = !self.Mo.isSelected; 
} 

@IBAction func DiToggle(_ sender: UIButton) { 
    self.Di.isSelected = !self.Di.isSelected; 
} 

@IBAction func MiToggle(_ sender: UIButton) { 
    self.Mi.isSelected = !self.Mi.isSelected; 
} 

@IBAction func DoToggle(_ sender: UIButton) { 
    self.Do.isSelected = !self.Do.isSelected; 
} 

@IBAction func FrToggle(_ sender: UIButton) { 
    self.Fr.isSelected = !self.Fr.isSelected; 
} 

@IBAction func SaToggle(_ sender: UIButton) { 
    self.Sa.isSelected = !self.Sa.isSelected; 
} 

@IBAction func SoToggle(_ sender: UIButton) { 
    self.So.isSelected = !self.So.isSelected; 
} 

func setSo(state: Bool) { 
    self.Mo.isSelected = state 
}

}

你检查你所有的IBOutlets是否连接正确 –

是的，那是我检查的第一件事。每个按钮连接正确。 –

你可以在setSo中放置一个断点，然后检查是否所有按钮都已启动并且不是零？ –

答

首先，你必须注册表格视图笔尖能够使用它。

添加在viewDidLoad：

self.tableView.register(UINib(nibName:"TableViewCellDays", bundle:nil), forCellReuseIdentifier: "TableViewCellDays")

更换您的变量声明如下：

var CellDays:TableViewCellDays?

您将在数据源的方法以后值分配给它。

接下来你tableView: UITableView, cellForRowAt得到这个细胞和实例变量CellDays分配给它：

override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell { 
    if(indexPath.section == 0) { 
     let cell = tableView.dequeueReusableCell(withIdentifier: "TableViewCellDays") as! TableViewCellDays 
     self.CellDays = cell 
     return cell 
    } else { 
     return Bundle.main.loadNibNamed("TableViewCellPicker", owner: self, options: nil)?.first as! TableViewCellPicker 
    } 
}

只有后，你可以叫你setSettingsButtons方法。

我收到错误：“参数标签不匹配任何可用的重载。” –

@ J.Doe你的'TableViewCellDays'是一个视图控制器吗？ – njuri

TableViewCellDays是一个自定义的TableViewCell笔尖。该函数由ViewController调用。 –

从Swift中的函数设置UiButton的状态

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