Swift 3 - 表达式太复杂，无法在合理的时间内解决；考虑将表达式分解为不同的子表达式

Question

我遇到了这个错误，我不知道如何解决!我正在搜索所有解决方案，但无法解决!

Expression was too complex to be solved in reasonable time; consider breaking up the expression into distinct sub-expressions

编辑:

    func createTarget(id: Int) {

        listdata = dbHelpr.getDatabase(rowId: id)

        for data in listdata {

            let lengthOfChar : CGFloat = data.ans.length
            let yAxis : CGFloat = self.view.frame.height / 2 + 70

            var width: CGFloat = view.frame.size.width - 40 // frame width
            var targetWidth: CGFloat = (width - (lengthOfChar - 1) * 5) / lengthOfChar
            var totalWidth: CGFloat = (targetWidth * lengthOfChar) + ((lengthOfChar - 1) * 5)

            if targetWidth > 50 {
                targetWidth = 50
            }

            for tar in data.ans.characters {


                var xAxis : CGFloat = (width / 2) - (totalWidth / 2) + (tar * targetWidth) + (tar * 5) + 20

                let targetLabel = UILabel(frame: CGRect(x: xAxis, y: yAxis, width: targetWidth, height: 5.0))
                targetLabel.backgroundColor = .white
                targetLabel.layer.masksToBounds = true
                targetLabel.layer.cornerRadius = 5
                targetLabel.text = String(describing: tar)
                targetLabel.textAlignment = .center
                targetLabel.textColor = .white
                self.view.addSubview(targetLabel)

            }

        }

    }

Answer 1

Expression was too complex to be solved in reasonable time; consider breaking up the expression into distinct sub-expressions

如前所述，打破它:

let preAxis1: GCFloat = (width / 2) - (totalWidth / 2) 
let preAxis2: GCFloat = (tar * targetWidth) + (tar * 5) + 20
let xAxis : CGFloat = preAxis1 + preAxis2

现在，这揭示了另一个(真正的)问题，而您所做的事情没有意义:

Binary operator '*' cannot be applied to operands of type 'Character' and 'CGFloat'

所以 tar 是一个 Character，而不是一个“数字”。在xAxis的计算中使用它是没有意义的。其实你要的是它的索引。

代替 for tar in data.ans.characters {，您可以这样做:

for (indexTar, tar) in data.ans.characters.enumerated() {

您正在迭代 data.ans 中的所有字符，indexTar 是当前索引，tar 是字符。因此，在之前的 xAxis 计算中，将 tar 替换为 indexTar 会更有意义并且应该有效。