Question

我正在将基于Kotlin的Android应用程序转换为基于Java的应用程序。但是，有几种Kotlin方法（尤其是arrayListOf(), sortedWith(), compareBy()方法）存在问题。 Android Studio的转换工具带来了更加令人困惑的结果。

Kotlin中的方法：

fun getSupportedVideoSize(mediaCodec: MediaCodec, mime: String, preferredResolution: Size): Size {
    
    if (mediaCodec.codecInfo.getCapabilitiesForType(mime)
            .videoCapabilities.isSizeSupported(preferredResolution.width, preferredResolution.height))
        return preferredResolution

    val resolutions = arrayListOf(
        Size(176, 144),
        Size(320, 240),
        Size(320, 180),
        Size(640, 360),
        Size(720, 480),
        Size(1280, 720),
        Size(1920, 1080)
    )

    val pix = preferredResolution.width * preferredResolution.height
    val preferredAspect = preferredResolution.width.toFloat() / preferredResolution.height.toFloat()

    val nearestToFurthest = resolutions.sortedWith(compareBy(
        {
            pix - it.width * it.height
        },
        {
            val aspect = if (it.width < it.height) it.width.toFloat() / it.height.toFloat()
            else it.height.toFloat()/it.width.toFloat()
            (preferredAspect - aspect).absoluteValue
        }))

    for (size in nearestToFurthest) {
        if (mediaCodec.codecInfo.getCapabilitiesForType(mime).videoCapabilities.isSizeSupported(size.width, size.height))
            return size
    }

    throw RuntimeException("Couldn't find supported resolution")
}

Java中的转换方法：

public static Size getSupportedVideoSize(MediaCodec mediaCodec, String mime, Size preferredResolution) {
    if (mediaCodec.getCodecInfo().getCapabilitiesForType(mime).getVideoCapabilities().isSizeSupported(preferredResolution.getWidth(), preferredResolution.getHeight())) {
        return preferredResolution;
    } else {
        ArrayList<Size> resolutions = new ArrayList<>();
        final int pix = preferredResolution.getWidth() * preferredResolution.getHeight();
        final float preferredAspect = (float)preferredResolution.getWidth() / (float)preferredResolution.getHeight();
    }
    
    for (nearestToFurthest: Size size) {
        if (mediaCodec.getCodecInfo().getCapabilitiesForType(mime).getVideoCapabilities().isSizeSupported(size.width, size.height)) {
            return size;
        }
    }
}

Answer 1

我不认识Kotlin，但我认为这些是等效的：

arrayListOf-> List.of

（这是无法修改的列表，如果您确实需要arraylist，请使用new ArrayList<>(Arrays.asList(...))）

sortedWith(compareBy(...))-> sort([Comparator or lambda expression])

arrayListOf（），sortedWith，compareBy与Java等效

1 个答案: