在SWIFT OS X中以编程方式添加和删除NSTextField

Question

我正在尝试在代表各种数据点的图形视图（想象Excel中的线图）上编写文本标签。

我使用tableView选择一个数据集。每次选择一个新的数据集时，图形都会重新绘制。

我可以使用自定义视图绘制线条图。没问题。

我可以使用）从drawRect中（称为下面的函数绘制文本标签：

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，如何当视图更新删除数据标签和一个新的数据集呈现。图形重新绘制，但文本标签仍然来自先前的数据集。

任何指导/建议，将不胜感激。

Answer 1

将下面的代码添加到函数的顶部已经解决了我的问题。

 let subViewsToRemove = self.subviews 

     for object in subViewsToRemove { 
      object.removeFromSuperview() 
     }