尽管在 Class 中声明了变量，但无法在范围内找到

Question

我正在使用 Swift 在 Xcode 上编写一个基本的 fps 应用程序。错误出现在我的 Bitmap.swift 文件中，该文件旨在将像素存储在二维数组中，以便有一种方法可以在应用程序中表示整个图像。

代码如下：

import UIKit

class Bitmap: UIViewController {

    public struct Bitmap
    {
        public private(set) var pixels: [Color]
        public let width: Int
        
        public init(width: Int, pixels: [Color])
        {
            self.width = width
            self.pixels = pixels
        }
    }
    
    override func viewDidLoad() {
        super.viewDidLoad()

        // Do any additional setup after loading the view.
    }
    

    /*
    // MARK: - Navigation

    // In a storyboard-based application, you will often want to do a little preparation before navigation
    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        // Get the new view controller using segue.destination.
        // Pass the selected object to the new view controller.
    }
    */

}


extension Bitmap
{
    var height: Int
    {
        return pixels.count / width
    }
    subscript(x: Int, y: Int) -> Color
    {
        get { return pixels[y * width + x] }
        set { pixels[y * width + x] = newValue}
    }
    convenience init(width: Int, height: Int, color: Color) {
        self.pixels = Array(repeating: color, count: width * height)
        self.width = width
    }
}

尽管在我的 class 中声明了“像素”和“宽度”，但我的扩展函数仍然出现这些错误：

“在范围内找不到 'pixels'” “在范围内找不到 'width'” “'Bitmap' 类型的值没有成员 'pixels'” “'Bitmap' 类型的值没有成员 'width'”

编辑：这是我的另一个文件“Color.swift”

的代码

import UIKit

class Color: UIViewController {
    
    public struct Color {
        public var r, g, b, a: UInt8
        
        public init(r: UInt8, g: UInt8, b: UInt8, a: UInt8 = 255)
        {
            self.r = r
            self.g = g
            self.b = b
            self.a = a
        }
    }


    override func viewDidLoad() {
        super.viewDidLoad()

        // Do any additional setup after loading the view.
    }
    

    /*
    // MARK: - Navigation

    // In a storyboard-based application, you will often want to do a little preparation before navigation
    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        // Get the new view controller using segue.destination.
        // Pass the selected object to the new view controller.
    }
    */

}


extension Color {
    static let clear = Color(r: 0, g: 0, b: 0, a: 0)
    static let black = Color(r: 0, g: 0, b: 0)
    static let white = Color(r: 255, g: 255, b: 255)
    static let gray = Color(r: 192, g: 192, b: 192)
    static let red = Color(r: 255, g: 0, b: 0)
    static let green = Color(r: 0, g: 255, b: 0)
    static let blue = Color(r: 0, g: 0, b: 255)
}

任何帮助将不胜感激。

Answer 1

您有一个 class 和一个 struct 名为 Bitmap。考虑到你打算如何使用它，我猜 class 是错误的。

删除 class 包裹在 struct 和删除 convenience，它不用于 structs:

public struct Bitmap
{
    public private(set) var pixels: [Color]
    public let width: Int
    
    public init(width: Int, pixels: [Color])
    {
        self.width = width
        self.pixels = pixels
    }
}


extension Bitmap
{
    var height: Int
    {
        return pixels.count / width
    }
    subscript(x: Int, y: Int) -> Color
    {
        get { return pixels[y * width + x] }
        set { pixels[y * width + x] = newValue}
    }
    init(width: Int, height: Int, color: Color) {
        self.pixels = Array(repeating: color, count: width * height)
        self.width = width
    }
}

尽管在 Class 中声明了变量，但无法在范围内找到

Cannot Find In Scope Despite Variable Declared In Class

xcode

pixel

ios

swift