ios - Swift字典更改值的变量

Question

很抱歉，如果已经讨论过，但我没有找到解决方案

我有一个结构:

struct Point2D
{
    var x: Double = 0.0
    var y: Double = 0.0
}

我也有一个类:

class Letter
{   
    var points3D: Dictionary<String,Point3D> = [:]
    var points2D: Dictionary<String,Point2D> = [:]
    var edges: Dictionary<String,Edge> = [:]
}

在某些方面:

class GraphicView: UIView {
   var letter:Letter!

   override func drawRect(rect: CGRect) {
      for (name,point3d) in letter.points3D {
            //Says String isn't convertable to DictionaryIndex<String,Point2D> 
            letter.points2D[name]!.x = point3d.x * (perspective / (perspective - point3d.z)) + imageWidth/2
            letter.points2D[name]!.y = point3d.y * (perspective / (perspective - point3d.z)) + imageHeight/2
        }
}

我正在尝试为键找到一些值(我知道它存在)并将该值的变量更改为另一个。怎么了？

Answer 1

也许 perspective、imageWidth 或 imageHeight 不是 Double？

尝试:

class GraphicView: UIView {
   var letter:Letter!

   override func drawRect(rect: CGRect) {
      for (name,point3d) in letter.points3D {
            letter.points2D[name]!.x = point3d.x * (Double(perspective) / (Double(perspective) - point3d.z)) + Double(imageWidth)/2
            letter.points2D[name]!.y = point3d.y * (Double(perspective) / (Double(perspective) - point3d.z)) + Double(imageHeight)/2
        }
}