Question

我在btnChk2行上有一个名为UITableview的按钮。当用户按下btnChk2按钮btnChk被选中时。上面的代码可以实现这一点，但是当我退出应用程序并将其打开时，复选框的状态就不一样了，我想要的例子是如果选中了一个行复选框，我希望当用户离开时应用程序和复出相同的复选框保持选中状态，尝试使用NSUserDefaults，但没有与我合作。

以下是有效的代码，但它不保存复选框的状态：

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {

    let cell = tableView.dequeueReusableCell(withIdentifier: "CheckBoxCell")
    if let lbl = cell?.contentView.viewWithTag(1) as? UILabel {
        lbl.text = "item-\(1)"
    }

    if let btnChk = cell?.contentView.viewWithTag(2) as? UIButton {
        btnChk.addTarget(self, action: #selector(checkboxClicked(_ :)), for: .touchUpInside)
    }

    if let btnChk2 = cell?.contentView.viewWithTag(100) as? UIButton {
        btnChk2.addTarget(self, action: #selector(checkboxClicked(_ :)), for: .touchUpInside)
    }
    return cell!
}

@objc func checkboxClicked(_ sender: UIButton) {

    guard let cell = sender.superview?.superview as? UITableViewCell else {
        return
    }

    if  sender.tag == 2 {

        if let btnChk2 = cell.contentView.viewWithTag(100) as? UIButton {
            if btnChk2.isSelected == true {
                btnChk2.isSelected = false
            }else{
                btnChk2.isSelected = true
            }
        }
        sender.isSelected = false
    }else if sender.tag == 100{
        if let btnChk = cell.contentView.viewWithTag(2) as? UIButton {
            if btnChk.isSelected == true {
                btnChk.isSelected = false

            }else{
                btnChk.isSelected = true
            }
        }
    }
}

Answer 1

好建议不要将userdefault用于此目的，用户默认仅用于用户设置目的，最好使用核心数据或保存在plist文件中。无论如何，这里是使用UserDefaults的解决方案。

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    var cell : UITableViewCell!
    // code to check for a particular tableView to display the data .
    if tableView == ScheduleTableView{



        cell = tableView.dequeueReusableCell(withIdentifier: "ScheduleCell", for: indexPath as IndexPath)
        let lblCity = cell.viewWithTag(1)as! UILabel
        lblCity.text = ScheduleArray[indexPath.row] as String

        if let btnChk2 = cell?.contentView.viewWithTag(100) as? UIButton {
            btnChk2.addTarget(self, action: #selector(checkboxClicked(_ :)), for: .touchUpInside)
        }

        if let btnChk2 = cell.contentView.viewWithTag(22) as? UIButton {

            btnChk2.isSelected = (UserDefaults.standard.integer(forKey: String(format: "indexpath%d", (indexPath.row))) == indexPath.row) ? true : false
        }  
    }
    if tableView == GoalsTableView{
        cell = tableView.dequeueReusableCell(withIdentifier: "GoalsCell", for: indexPath as IndexPath)
        let lbl3 = cell.viewWithTag(2)as! UILabel
        lbl3.text = GoalsArray[indexPath.row]as? String
    }
    return cell
}


@objc func checkboxClicked(_ sender: UIButton) {
    print("AAAA")

    // sender.isSelected = !sender.isSelected


    guard let cell = sender.superview?.superview as? UITableViewCell else {
        return
    }

    let buttonPosition:CGPoint = sender.convert(CGPoint.zero, to:self.ScheduleTableView)
    let indexPath = self.ScheduleTableView.indexPathForRow(at: buttonPosition)

    if  sender.tag == 100 {

        if let btnChk2 = cell.contentView.viewWithTag(22) as? UIButton {
            if btnChk2.isSelected == true {
                btnChk2.isSelected = false
                UserDefaults.standard.set(-1, forKey: String(format: "indexpath%d", (indexPath?.row)!))

            }else{
                btnChk2.isSelected = true
                UserDefaults.standard.set(indexPath?.row, forKey: String(format: "indexpath%d", (indexPath?.row)!))
            }
        }
        sender.isSelected = false
    }


}

Answer 2

您可以在NSUserDefault中保存所选按钮编号，然后在cellForRowAtIndexpath中使用相同的按钮编号。像是

NSString *valueToSave = @"button1";
[[NSUserDefaults standardUserDefaults] setObject:valueToSave forKey:@"SelectedButton"];
[[NSUserDefaults standardUserDefaults] synchronize];

NSString *savedValue = [[NSUserDefaults standardUserDefaults]
    stringForKey:@"SelectedButton"];

然后在cellForRowAtIndexpath中，您可以检查来自NSUserDefaults的值

在UITableView行（Swift）中保存按钮的选择状态

2 个答案: