arrays - 通过数据库中的字符使用 for 循环创建 UILabel

Question

我正在通过 SQLite 数据库中的字符使用 For 循环创建 UILabe，我该怎么做？

这是我的代码:

for data in listdata {
    for tar in [data.ans.characters] as NSArray {
        var counter = ""
        counter = tar as! String
        let targetLabel = UILabel(frame: CGRect(x: xAxis, y: yAxis, width: 50, height: 50))
        targetLabel.backgroundColor = .white
        targetLabel.layer.masksToBounds = true
        targetLabel.layer.cornerRadius = 5
        targetLabel.text = counter
        targetLabel.textAlignment = .center
        self.view.addSubview(targetLabel)
    }
}

data.ans 是字符串数据，我将其转换为字符数组，它是从 listdata 派生的，当我输入前面的代码时，我崩溃了!他的按摩是:

Could not cast value of type 'Swift.String.CharacterView'

当编辑我的代码时:

for data in listdata {
    for tar in AnyObject[data.ans.characters] as NSArray { // Instance member 'subscript' cannot be used on type 'AnyObject'
        var counter = ""
        counter = tar as String
        let targetLabel = UILabel(frame: CGRect(x: xAxis, y: yAxis, width: 50, height: 50))
        targetLabel.backgroundColor = .white
        targetLabel.layer.masksToBounds = true
        targetLabel.layer.cornerRadius = 5
        targetLabel.text = counter
        targetLabel.textAlignment = .center
        self.view.addSubview(targetLabel)
    }
}

给我错误消息:

Instance member 'subscript' cannot be used on type 'AnyObject'

解决了什么？我如何根据 SQLite 数据库中的字符数循环 UILabel？

我想在图片中像这样创建，但是来自 SQLite 数据库 (data.ans):

Answer 1

characters 属性已经是可迭代的。您还有另外两个问题:

1. 您需要将 tar 转换为 String 以将其分配给 .text 属性
2. 您需要为每次迭代添加 width 以及 x 的一些增量

代码

import UIKit
import PlaygroundSupport

let view = UIView(frame: CGRect(x: 0, y: 0, width: 345, height: 70))

class Data {
    var ans = "LONDON"
}
var data = Data()
var x = 10
var y = 10
for tar in data.ans.characters {
    let targetLabel = UILabel(frame: CGRect(x: x, y: y, width: 50, height: 50))
    x += 50 + 5
    targetLabel.backgroundColor = .white
    targetLabel.layer.masksToBounds = true
    targetLabel.layer.cornerRadius = 5
    targetLabel.text = String(tar)
    targetLabel.textAlignment = .center
    view.addSubview(targetLabel)
    let xString = String(format: "%\(03)d", x)
    print("x = \(xString), tar = \(tar)")
}

PlaygroundPage.current.liveView = view
PlaygroundPage.current.needsIndefiniteExecution = true

这是在 Swift playground 中运行的。

从菜单中选择 View -> Assistant Editor -> Show Assistant Editor 以查看 UIView。

输出

x =  65, tar = L
x = 120, tar = O
x = 175, tar = N
x = 230, tar = D
x = 285, tar = O
x = 340, tar = N