如何在Go中使用macOS / OS X框架

For example, how to use CoreGraphics and CoreFoundation to manipulate the screen and process data on macOS.

Let's say we want to use CoreGraphics and CoreFoundation to capture the screen and get the image data:

package main

// To use the two libraries we need to define the respective flags, include the required header files and import "C" immediately after
import (
    // #cgo LDFLAGS: -framework CoreGraphics
    // #cgo LDFLAGS: -framework CoreFoundation
    // #include <CoreGraphics/CoreGraphics.h>
    // #include <CoreFoundation/CoreFoundation.h>
    "C"
    "image"
    "reflect"
    "unsafe"
    // other packages...
)

func main() {
    displayID := C.CGMainDisplayID()
    width := int(C.CGDisplayPixelsWide(displayID))
    height := int(C.CGDisplayPixelsHigh(displayID))
    rawData := C.CGDataProviderCopyData(C.CGImageGetDataProvider(C.CGDisplayCreateImage(displayID)))

    length := int(C.CFDataGetLength(rawData))
    ptr := unsafe.Pointer(C.CFDataGetBytePtr(rawData))

    var slice []byte
    hdrp := (*reflect.SliceHeader)(unsafe.Pointer(&slice))
    hdrp.Data = uintptr(ptr)
    hdrp.Len = length
    hdrp.Cap = length

    imageBytes := make([]byte, length)

    for i := 0; i < length; i += 4 {
    imageBytes[i], imageBytes[i+2], imageBytes[i+1], imageBytes[i+3] = slice[i+2], slice[i], slice[i+1], slice[i+3]
        }

    C.CFRelease(rawData)

    img := &image.RGBA{Pix: imageBytes, Stride: 4 * width, Rect: image.Rect(0, 0, width, height)}

    // There we go, we can now save or process the image further
    }