我的表視圖重用選定單元格時滾動 - 在SWIFT

Question

早安

我的問題是，我的表視圖重用選定單元格時，我向下滾動，再升..我的意思是，當我選擇從一個細胞然後向下滾動，一些我沒有選擇的單元格顯示被選中，當我再次向上滾動時，從上向下選擇的一些單元格也不會被選中，當發生這種情況時，我再次選擇蘋果以選擇不僅僅是一個單元格，允許..我想提到的是，我試圖保存從'didSelectRowAtIndexPath'舊索引路徑，我在'CellForRowAtIndexPath'像這樣檢查它，但它不工作：

if (old == indexpath) 
{ 
     cell?.backgroundColor = UIColor.redColor() 
     cell?.textLabel?.backgroundColor = UIColor.whiteColor() //to change only the thumbnail color and keep the cell color 
} 

else { 
     cell?.backgroundColor = UIColor.whiteColor() 
} 

現在，這裏是我的代碼

func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell { 
    var cell = myTable.dequeueReusableCellWithIdentifier("WorkCell") as UITableViewCell 
    cell.tag = (indexPath.row) + 1 
    cell.textLabel?.text = Berufs[indexPath.row] 
    var img = UIImageView(frame: CGRect(x: 10, y: 3, width: 40 , height: 40)) 
    cell.selectionStyle = UITableViewCellSelectionStyle.None 
    img.image = UIImage(named: "transparent.png") 
    cell.indentationLevel = 1 
    cell.indentationWidth = 45 
    cell.addSubview(img) 
    return cell 
} 

var old = 1000 

func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) 
{ 
    let indexPath = tableView.indexPathForSelectedRow() 
    let cell = tableView.cellForRowAtIndexPath(indexPath!) 
    var tmpCell = view.viewWithTag(old) 
    var rowNum = (cell?.tag)! - 1 

    if (cell?.backgroundColor == UIColor.redColor()) 
    { 
     cell?.backgroundColor = UIColor.whiteColor() 
    } 
    else if (cell?.backgroundColor != UIColor.redColor()) 
    { 
     tmpCell?.backgroundColor = UIColor.whiteColor() 
     cell?.backgroundColor = UIColor.redColor() 
     cell?.textLabel?.backgroundColor = UIColor.whiteColor() 

     println("du interssiert dich für \(Berufs[rowNum])") 
    } 

    old = rowNum + 1 

} 

Answer 1

您目前選擇狀態存儲在的backgroundColor 。這不是一個好主意，因爲出於性能原因，單元格將被tableView重用。

您應該將選定的indexPaths保存在數據模型中。如果你想允許多個選擇，你可以將選擇的indexPaths存儲在一個NSMutableSet中。

override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell { 
    let cell = tableView.dequeueReusableCellWithIdentifier("Cell", forIndexPath: indexPath) as UITableViewCell 
    cell.selectionStyle = .None 
    configure(cell, forRowAtIndexPath: indexPath) 
    return cell 
} 

var selectedIndexPaths = NSMutableSet() 

func configure(cell: UITableViewCell, forRowAtIndexPath indexPath: NSIndexPath) { 
    cell.textLabel!.text = "Row \(indexPath.row)" 
    if selectedIndexPaths.containsObject(indexPath) { 
     // selected 
     cell.backgroundColor = UIColor.redColor() 
    } 
    else { 
     // not selected 
     cell.backgroundColor = UIColor.whiteColor() 
    } 
} 


override func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) { 
    if selectedIndexPaths.containsObject(indexPath) { 
     // deselect 
     selectedIndexPaths.removeObject(indexPath) 
    } 
    else { 
     // select 
     selectedIndexPaths.addObject(indexPath) 
    } 
    let cell = tableView.cellForRowAtIndexPath(indexPath)! 
    configure(cell, forRowAtIndexPath: indexPath) 
} 

如果您只需要單一選擇，您應該將選定的indexPath保存在NSIndexPath中？實例變量

override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell { 
    let cell = tableView.dequeueReusableCellWithIdentifier("Cell", forIndexPath: indexPath) as UITableViewCell 
    cell.selectionStyle = .None 
    configure(cell, forRowAtIndexPath: indexPath) 
    return cell 
} 

var selectedIndexPath: NSIndexPath? 

func configure(cell: UITableViewCell, forRowAtIndexPath indexPath: NSIndexPath) { 
    cell.textLabel!.text = "Row \(indexPath.row)" 
    if selectedIndexPath == indexPath { 
     // selected 
     cell.backgroundColor = UIColor.redColor() 
    } 
    else { 
     // not selected 
     cell.backgroundColor = UIColor.whiteColor() 
    } 
} 

override func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) { 
    if selectedIndexPath == indexPath { 
     // selected same cell -> deselect all 
     selectedIndexPath = nil 
    } 
    else { 
     // select different cell 
     let oldSelectedIndexPath = selectedIndexPath 
     selectedIndexPath = indexPath 

     // refresh old cell to clear old selection indicators 
     var previousSelectedCell: UITableViewCell? 
     if let previousSelectedIndexPath = oldSelectedIndexPath { 
      if let previousSelectedCell = tableView.cellForRowAtIndexPath(previousSelectedIndexPath) { 
       configure(previousSelectedCell, forRowAtIndexPath: previousSelectedIndexPath) 
      } 
     } 
    } 
    let selectedCell = tableView.cellForRowAtIndexPath(indexPath)! 
    configure(selectedCell, forRowAtIndexPath: indexPath) 
} 

Answer 2

我前一陣子有同樣的問題，我所做的是，我添加了一個名爲isset到CustomTableViewCell新變量（布爾），當我創建了細胞的第一次，我把它改成真實的，所以以後我想重新使用已設置的細胞，我剛回國的arleady設置一個，不設置又是：

let cell = tableView.dequeueReusableCellWithIdentifier("Cellidentifier", forIndexPath: indexPath) as CustomTableViewCell 

if cell.isset 
{ 
     return cell 
} 

//set your cell here 
cell.isset = true 
return cell