shalyf

#import <mach/mach.h>
#import <sys/sysctl.h>

+ (double)cpuUsage {
    kern_return_t kr;
    task_info_data_t tinfo;
    mach_msg_type_number_t task_info_count;
    
    task_info_count = TASK_INFO_MAX;
    kr = task_info(mach_task_self(), TASK_BASIC_INFO, (task_info_t)tinfo, &task_info_count);

shalyf

func resolveDictionary(fromTXTRecord data: Data) -> [String: String] {
    var dict = [String: String]()
    var offset = 0
    let bytes = data.bytes
    while offset < bytes.count {
        let recordLength = Int(bytes[offset])
        offset += 1
        print(recordLength)
        if recordLength > 0 {
            let subBytes = bytes[offset..<offset + recordLength]

shalyf

navigationController?.navigationBar.setBackgroundImage(UIImage(), for: .default)
navigationController?.navigationBar.shadowImage = UIImage()

shalyf

let resources = PHAssetResource.assetResources(for: asset)
let videoResource = resources.first(where: { $0.type == .video || $0.type == .pairedVideo })!
let url = URL(fileURLWithPath: FileManager.Folder.tmp.append(pathComponent: "test.MOV"))
let resourceOptions = PHAssetResourceRequestOptions()
resourceOptions.isNetworkAccessAllowed = true
PHAssetResourceManager.default().writeData(for: videoResource, toFile: url, options: resourceOptions, completionHandler: { (error) in
    print(error == nil)
})

shalyf

expr (Class)NSClassFromString(@"IBARevealLoader") == nil ? (void *)dlopen("/Applications/Reveal.app/Contents/SharedSupport/iOS-Libraries/RevealServer.framework/RevealServer", 0x2) : ((void*)0)

shalyf

#define clamp(a) (a>255?255:(a<0?0:a))

+ (UIImage *)imageFromSampleBuffer:(CMSampleBufferRef)sampleBuffer {
    CVImageBufferRef imageBuffer = CMSampleBufferGetImageBuffer(sampleBuffer);
    CVPixelBufferLockBaseAddress(imageBuffer, 0);

    if (CVPixelBufferGetPlaneCount(imageBuffer) < 2) {
        CVPixelBufferUnlockBaseAddress(imageBuffer, 0);
        return nil;
    }

shalyf

启动屏中要添加图片经常会出现图片无法展示的问题
查了很多资料，最后得出一个对我来说有用的结论
1、将图片添加到根目录中
2、将图片添加到Assets.xcassets中
3、在LaunchScreen.storyboard中添加一个UIImageView，然后添加Assets.scassets中的图片即可

shalyf

let isBlackColor = { (x: Int, y: Int) -> Bool in
    let byteIndex = (bytesPerRow * y) + x * bytesPerPixel
    let r = CGFloat(rawData[byteIndex])
    let g = CGFloat(rawData[byteIndex + 1])
    let b = CGFloat(rawData[byteIndex + 2])
    // https://stackoverflow.com/a/12043228
    let luma = 0.2126 * r + 0.7152 * g + 0.0722 * b
    return luma < 40
}

shalyf

在Swift中使用Google Nearby API的时候，遇到了以下错误

Undefined symbols for architecture arm64:
"OBJC_CLASS$_GNSMessageManager", referenced from:
objc-class-ref in TBGNSMessager.o
"OBJC_CLASS$_GNSMessage", referenced from:
objc-class-ref in TBGNSMessager.o

shalyf

import Accelerate.vImage

func getImageBuffer(from pixelBuffer: CVPixelBuffer) -> vImage_Buffer? {
    var buffer = vImage_Buffer()
    let bitmapInfo = CGBitmapInfo(rawValue: CGBitmapInfo.byteOrder32Little.rawValue | CGImageAlphaInfo.first.rawValue)
    var cgFormat = vImage_CGImageFormat(bitsPerComponent: 8,
                                        bitsPerPixel: 32,
                                        colorSpace: nil,
                                        bitmapInfo: bitmapInfo,
                                        version: 0,