如何在数组中添加图像

Question

尝试将图像添加到数组中，然后需要将四个数组合并为一个数组。 我想做的是：

var arrFiltersImagesList : NSMutableArray = []
var arrRoomInfoImages = Array<UIImage>()
var arrPropertyInfoImages = Array<UIImage>()
var arrAvailabilityImages = Array<UIImage>()
var arrPreferencesImages = Array<UIImage>()

arrRoomInfoImages += [UIImage(named: "ic_roomType_small.png")!, UIImage(named: "ic_furnished_small.png")!, UIImage(named: "ic_numberBedrooms_small.png")!]

    arrPropertyInfoImages += [UIImage(named: "ic_small.png")!, UIImage(named: "ic_propertyType_small.png")!, UIImage(named: "ic_numberBedrooms_small.png")!, UIImage(named: "ic_numberBathrooms_small.png")!, UIImage(named: "ic_amenities Copy_small.png")!]

    arrAvailabilityImages += [UIImage(named: "ic_roomType_small.png")!, UIImage(named: "ic_furnished_small.png")!, UIImage(named: "ic_ensuite_small.png")!]

    arrPreferencesImages += [UIImage(named: "ic_roomType_small.png")!, UIImage(named: "ic_furnished_small.png")!, UIImage(named: "ic_ensuite_small.png")!]

arrFiltersImagesList.addObject(arrRoomInfoImages)
    arrFiltersImagesList.addObject(arrPropertyInfoImages)
    arrFiltersImagesList.addObject(arrAvailabilityImages)
    arrFiltersImagesList.addObject(arrPreferencesImages)

关注了这个link，但根本没有用 输出很糟糕。请指导正确的方法。 谢谢

Answer 1

我会通过将数组构建到 let 变量而不是 var 变量中来做到这一点，利用 Swift 推断类型的能力：

import UIKit

let arrRoomInfoImages = [
  UIImage(named: "ic_roomType_small.png"),
  UIImage(named: "ic_furnished_small.png"),
  UIImage(named: "ic_numberBedrooms_small.png")].flatMap { $0 }

let arrPropertyInfoImages = [
  UIImage(named: "ic_small.png"),
  UIImage(named: "ic_propertyType_small.png"),
  UIImage(named: "ic_numberBedrooms_small.png"),
  UIImage(named: "ic_numberBathrooms_small.png"),
  UIImage(named: "ic_amenities Copy_small.png")].flatMap { $0 }

let arrAvailabilityImages = [
  UIImage(named: "ic_roomType_small.png"),
  UIImage(named: "ic_furnished_small.png"),
  UIImage(named: "ic_ensuite_small.png")].flatMap { $0 }

let arrPreferencesImages = [
  UIImage(named: "ic_roomType_small.png"),
  UIImage(named: "ic_furnished_small.png"),
  UIImage(named: "ic_ensuite_small.png")].flatMap { $0 }

let arrFiltersImagesList = [
  arrRoomInfoImages,
  arrPropertyInfoImages,
  arrAvailabilityImages,
  arrPreferencesImages]

请注意，我不会强制解开 init 方法的返回值。相反，我使用flatMap 剔除数组中的任何nil 值。这是一种在加载图像时处理错误的快速而简单的方法，您可能需要做一些更复杂的事情来确保正确处理任何未加载的图像。