將GDI32.dll位圖保存到Golang中的磁盤

Question

我的第一個SO問題:-)我希望通過在Windows計算機上調用User32.dll和GDI32.dll（項目需求）來從Golang獲取屏幕截圖。

我有一個包含屏幕截圖像​​素的位圖句柄。但是，我不知道如何訪問其數據或如何將其保存到磁盤。任何人都知道如何將GDI位圖映射到Golang []字節，然後保存爲JPG或PNG格式？

package main 
import "syscall" 

var (
    user32   = syscall.NewLazyDLL("user32.dll") 
    procGetClientRect = user32.NewProc("GetClientRect") 
    // etc... 
    gdi32    = syscall.NewLazyDLL("gdi32.dll") 
    procCreateDC  = gdi32.NewProc("CreateDC") 
    SRCCOPY  uint = 13369376 
    //etc... 
) 

// 
// omitted for brevity 
// 
func TakeDesktopScreenshotViaWinAPI() { 

    // these are all calls to user32.dll or gdi32.dll 
    hDesktop := GetDesktopWindow() 
    desktopRect := GetClientRect(hDesktop) 
    width := int(desktopRect.Right - desktopRect.Left) 
    height := int(desktopRect.Bottom - desktopRect.Top) 

    // create device contexts 
    srcDC := GetDC(hDesktop) 
    targetDC := CreateCompatibleDC(srcDC) 

    // create bitmap to copy to 
    hBitmap := CreateCompatibleBitmap(targetDC, width, height) 

    // select the bitmap into target DC 
    hOldSelection := SelectObject(targetDC, HGDIOBJ(hBitmap)) 

    //bit block transfer from src to target 
    BitBlt(targetDC, 0, 0, width, height, srcDC, 0, 0, SRCCOPY) 

    // how to save the the data in 
    // *hBitmap ??? 

    // restore selection 
    SelectObject(targetDC, hOldSelection) 

    // clean up 
    DeleteDC(HDC(targetDC)) 
    ReleaseDC(hDesktop, srcDC) 
    DeleteObject(HGDIOBJ(hBitmap)) 
} 

Answer 1

你可以只使用the screenshot library通過vova616，或者看看在screenshot_windows.go爲所需的轉換方法。

按照所提供的示例：

package main 

import (
    "github.com/vova616/screenshot" 
    "image/png" 
    "os" 
) 

func main() { 
    img, err := screenshot.CaptureScreen() 
    if err != nil { 
     panic(err) 
    } 
    f, err := os.Create("./ss.png") 
    if err != nil { 
     panic(err) 
    } 
    err = png.Encode(f, img) 
    if err != nil { 
     panic(err) 
    } 
    f.Close() 
}