在SWIFT OS X中以編程方式添加和刪除NSTextField

Question

我正在嘗試在代表各種數據點的圖形視圖（想象Excel中的線圖）上編寫文本標籤。

我使用tableView選擇一個數據集。每次選擇一個新的數據集時，圖形都會重新繪製。

我可以使用自定義視圖繪製線條圖。沒問題。

我可以使用）從drawRect中（稱爲下面的函數繪製文本標籤：

func drawDataPointLabels(size: CGSize) { //size is the view.bounds 

    var dataLabelsArray: [(NSColor, String, NSRect)] = [] 

    // graphDetails contain an array of tuples [(),(),(),()] - this represents one graph type = eg Monthly Fees ** there will be a maximum of 12 items in the array 
    for graphDetails in graphDetailsArray { 

     // each dataPoint object is a tuple (graphType: columnLabel: columnColor: columnHeight: columnNumber:) representing one dataPoint 
     for dataPoint in graphDetails { 
      let graphHeight = size.height/2 
      let graphWidth = size.width - graphOrigin.x - rightMargin 
      let columnAndGapSize = graphWidth/25 
      let labelX: CGFloat = (graphOrigin.x + columnAndGapSize) + (columnAndGapSize * dataPoint.columnNumber) * 2 
      let labelY: CGFloat = dataPoint.columnHeight * (graphHeight - topMargin - bottomMargin) 

      // determine the location and frame for the text label to match dataPoint 
      let textFrame = NSRect(x: labelX, y: labelY, width: 30, height: 10) 
      let dataPointTuple = (dataPoint.columnColor, dataPoint.columnLabel, textFrame) 
      dataLabelsArray.append(dataPointTuple) 
     } 

     for dataPoint in dataLabelsArray { 
      let (color, label, frameRect) = dataPoint 
      let lblDataPoint = NSTextField(frame: frameRect) 
      lblDataPoint.stringValue = label 
      lblDataPoint.backgroundColor = backgroundColor 
      lblDataPoint.textColor = color 
      self.addSubview(lblDataPoint) 
     } 
    } 
} 

但是，我不能工作，如何當視圖更新刪除數據標籤和一個新的數據集呈現。圖形重新繪製，但文本標籤仍然來自先前的數據集。

任何指導/建議，將不勝感激。

Answer 1

將下面的代碼添加到函數的頂部已經解決了我的問題。

 let subViewsToRemove = self.subviews 

     for object in subViewsToRemove { 
      object.removeFromSuperview() 
     }