ContiguousArrayBuffer.swift 第 444 行致命错误：索引超出范围：

Question

整体代码运行良好，我将 pulltorefreshControl 用于 UITableView。每当我通过 pulltoRefresh 刷新它时，它都会给我 Fatal error: Index out of range: file Swift/ContiguousArrayBuffer.swift, line 444

在 cellForRowAt 函数的 let dic = Appdata![indexPath.row] 上突出显示错误。

我的代码很简单，只是从 JSON 响应中获取数据。

在顶部声明：var Appdata : [Appointment]? = []

JSON 响应代码：

func appointmentCall(_ someDateTime:Date) {
        
        self.Appdata?.removeAll()        
        DataProvider.main.serviceGetAppointment(date: someDateTime, callback: {success, result in
            
            do{
                if(success){

                    let decoder = JSONDecoder()
                    let response = try decoder.decode(ResponseData.self, from: result! as! Data)
                    self.Appdata = response.appointments
    
                    self.tableView.reloadData()
                    
                    return true
                }else{
                    self.Appdata?.removeAll()
                    self.tableView.reloadData()
                    return false
                }
            }catch let error {
                
                print(error as Any)
                return false
            }
        })
        
       
        
    }

下拉刷新功能：

@objc func refresh(_ sender: AnyObject) {
        
    // refresh tableview datasource
    DispatchQueue.main.async {
        sender.beginRefreshing()
        self.Appdata?.removeAll()
        self.appointmentCall(appointDate)
        self.refreshControl.endRefreshing()
    }
        
}

TableView 代码：

func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return Appdata?.count ?? 0
}

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    
    let cell = tableView.dequeueReusableCell(withIdentifier: "AppointmentTableViewCell", for: indexPath) as! AppointmentTableViewCell        
    let dic = Appdata![indexPath.row]
    
    
    cell.rightView.backgroundColor = dic.backgroundColorLight?.toColor() ?? ("#cfd8dc").toColor()
    cell.rightView.layer.applySketchShadow()
    cell.topLabel.text = dic.projectName
    cell.midLabel.text = dic.subTitle
    cell.leftView.backgroundColor = dic.backgroundColorDark?.toColor() ?? ("#556f7b").toColor()
    cell.rightLabel.text = dic.projectDistrict
    cell.leftTopLabel.text = dic.appointmentHour
    cell.leftBotLabel.text = dic.controlHour
    cell.botLabel.text = dic.projectFirmName
    
    return cell
    
}