我有一個問題,我不明白,因爲我是新的iPhone應用程序編程和Swift。發現零當試圖從表格單元格讀取
我有一個Swift中的TableView,我用它來顯示一些結果。我爲每個單元格添加了一個按鈕,以便用戶可以選擇不同的單元格,然後按刪除鍵以刪除單元格中顯示的結果。
只有少數的結果工作得很好,但現在我已經開始得到零例外。
當我嘗試獲取特定行的單元格時,程序在函數getIndexToDelete中崩潰。
這裏就是我處理表的代碼:
import UIKit
class DailyResultTable: UIViewController, UITableViewDataSource, UITableViewDelegate {
var results = Results()
var yearShownIndex = 0
var monthShownIndex = 0
var dayShownIndex = 0
@IBOutlet weak var tableView: UITableView!
@IBOutlet weak var DeleteButton: UIButton!
override func viewDidLoad() {
super.viewDidLoad()
// self.view.backgroundColor = UIColor(patternImage: UIImage(named: "StatisticBackground")!)
}
// DataSource
func numberOfSectionsInTableView(tableview: UITableView) -> Int {
return 1
}
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
// return (self.results?.getDayList(yearShownIndex, posMonth: monthShownIndex).count)!
print("return number of rows")
if (results.getYearList().count > 0){
if (results.getMonthList(yearShownIndex).count > 0){
if (results.getDayList(yearShownIndex, posMonth: monthShownIndex).count > dayShownIndex){
return (results.getDayList(yearShownIndex, posMonth: monthShownIndex)[dayShownIndex].results.count)
}
}
}
print("No numbers to show return 0")
return 0;
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("DayResultCell", forIndexPath: indexPath) as! ResultTableCell
let row = indexPath.row
//cell.ResultField.text = String((results?.getDayList(yearShownIndex, posMonth: monthShownIndex)[row].day)!) + "/" + String((results?.getMonthList(yearShownIndex)[monthShownIndex].month)!)
let res = results.getDayList(yearShownIndex, posMonth: monthShownIndex)[dayShownIndex].results[row].result
let maxRes = results.getDayList(yearShownIndex, posMonth: monthShownIndex)[dayShownIndex].results[row].maxresult
let discipline = results.getDayList(yearShownIndex, posMonth: monthShownIndex)[dayShownIndex].results[row].discipline
let text1 = String(res) + "/"
let text2 = String(maxRes)
let text3 = " - " + discipline
let text = text1 + text2 + text3
print(text)
cell.ResultField.text = text
return cell
}
// Delegate
func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
}
@IBAction func CheckBox(sender: UIButton) {
let image = UIImage(named: "Selected") as UIImage!
let selected = sender.selected
sender.selected = !selected
sender.setImage(image, forState: .Selected)
}
func getIndexToDelete()->[Int]{
var indices = [Int]()
for i in 0..<tableView.numberOfRowsInSection(0){
let indexPath = NSIndexPath(forRow: i, inSection: 0)
// Here does the program crash
let cell = tableView.cellForRowAtIndexPath(indexPath) as! ResultTableCell
if (cell.CheckBoxButton.selected){
indices += [i]
}
}
return indices
}
@IBAction func DeletePressed(sender: UIButton) {
let deleteIndices = getIndexToDelete()
var goback = false;
var count = 0;
for index in deleteIndices{
print("Count: " + String(count))
results.ListResults[yearShownIndex].months[monthShownIndex].day[dayShownIndex].results.removeAtIndex(index-count)
count += 1
print(String((results.getDayList(yearShownIndex, posMonth: monthShownIndex)[dayShownIndex].results.count)));
}
loadView()
results.recreatePlainResult()
results.saveResults()
if (results.ListResults[yearShownIndex].months[monthShownIndex].day[dayShownIndex].results.count == 0){
print(String(results.ListResults[yearShownIndex].months[monthShownIndex].day.count))
results.ListResults[yearShownIndex].months[monthShownIndex].day.removeAtIndex(dayShownIndex)
results.recreatePlainResult()
results.saveResults()
print(String(results.ListResults[yearShownIndex].months[monthShownIndex].day.count))
goback = true
}
if (results.ListResults[yearShownIndex].months[monthShownIndex].day.count == 0){
results.ListResults[yearShownIndex].months.removeAtIndex(monthShownIndex)
results.recreatePlainResult()
results.saveResults()
goback = true
}
if (results.ListResults[yearShownIndex].months.count == 0){
results.ListResults.removeAtIndex(monthShownIndex)
results.recreatePlainResult()
results.saveResults()
goback = true
}
if (goback){
// return;
navigationController?.popViewControllerAnimated(true)
}
}
}
這裏是ResultTableCell:
import UIKit
class ResultTableCell: UITableViewCell {
@IBOutlet weak var ResultField: UITextField!
@IBOutlet weak var CheckBoxButton: UIButton!
}
我當然可以把let cell = tableView.cellForRowAtIndexPath(indexPath) as! ResultTableCell
一個if子句中,但隨後其他奇怪的事情發生。
如果你想確定哪個按鈕在tableview中被按下,我建議你設置button.tag = indexPath.row ...這樣你就可以確切地知道你按下了什麼按鈕,而沒有這個可怕的事情......設置標籤在cellForRowAtIndexPath –