“该类别不符合键值编码".使用CoreImage [英] "This class is not key value coding-compliant" using CoreImage

问题描述

我正在Swift中开发一个简单的MacOS 命令行应用程序.我创建了一个自定义的CoreImage过滤器，使用起来很麻烦.该代码可以很好地编译，但是在运行时会退出，并显示以下错误:

I'm working on a simple MacOS command-line application in Swift. I created a custom CoreImage filter and having troubles to use it. The code compiles just fine but when it runs it exits with the following error:

***由于未捕获的异常'NSUnknownKeyException'而终止应用程序，原因:'[setValue:forUndefinedKey:]: 此类与键inputImage的键值编码不兼容.'

*** Terminating app due to uncaught exception 'NSUnknownKeyException', reason: '[ setValue:forUndefinedKey:]: this class is not key value coding-compliant for the key inputImage.'

在此问题上的任何帮助将不胜感激.尝试在SO上寻找答案，但是不幸的是，由于我的应用程序没有使用Storyboards或Outlets(它是纯命令行)，所以我无能为力.

Any help with this issue would be greatly appreciated. Tried searching for an answer on SO but since my application does not use Storyboards or Outlets (it's pure command-line) unfortunately I couldn't help myself.

我的程序在这一行中断:

My program breaks on this line:

filter.setValue(inputImage, forKey: kCIInputImageKey)

这是我正在使用的代码:

Here's the code I'm using:

class CustomFilter:CIFilter {
    var inputImage:CIImage?

    let kernelString = CIKernel(string:
        "kernel vec4 chromaKey( __sample s) { \n" +
            "  vec4 newPixel = s.rgba;" +
            "  newPixel[0] = 0.0;" +
            "  newPixel[2] = newPixel[2] / 2.0;" +
            "  return newPixel;\n" +
        "}"
    )

    override var outputImage:CIImage! {
        guard
            let inputImage = inputImage
        else {
            return nil
        }

        let extent = inputImage.extent

        let blur = kernelString?.apply(
            withExtent: extent,
            roiCallback: {
                (index, rect) in
                return rect
            },
            arguments: [inputImage])

        return blur!.cropping(to: extent)
    }
}

let filter = CustomFilter()

filter.setValue(inputImage, forKey: kCIInputImageKey) // it breaks here

guard
    let result = filter.outputImage
else {
    return nil
}

return result

推荐答案

键值编码兼容属性必须标记为dynamic

Key value coding-compliant properties must be marked as dynamic

dynamic var inputImage : CIImage?

，在Swift 4中，甚至是@objc

and in Swift 4 even as @objc

@objc dynamic var inputImage : CIImage?

这篇关于“该类别不符合键值编码".使用CoreImage的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！