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@EliCDavis
Created September 15, 2020 20:29
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Find Windows Handle Of Application In Golang
package main
import (
"fmt"
"log"
"syscall"
"unsafe"
)
var (
user32 = syscall.MustLoadDLL("user32.dll")
procEnumWindows = user32.MustFindProc("EnumWindows")
procGetWindowTextW = user32.MustFindProc("GetWindowTextW")
)
func EnumWindows(enumFunc uintptr, lparam uintptr) (err error) {
r1, _, e1 := syscall.Syscall(procEnumWindows.Addr(), 2, uintptr(enumFunc), uintptr(lparam), 0)
if r1 == 0 {
if e1 != 0 {
err = error(e1)
} else {
err = syscall.EINVAL
}
}
return
}
func GetWindowText(hwnd syscall.Handle, str *uint16, maxCount int32) (len int32, err error) {
r0, _, e1 := syscall.Syscall(procGetWindowTextW.Addr(), 3, uintptr(hwnd), uintptr(unsafe.Pointer(str)), uintptr(maxCount))
len = int32(r0)
if len == 0 {
if e1 != 0 {
err = error(e1)
} else {
err = syscall.EINVAL
}
}
return
}
func FindWindow(title string) (syscall.Handle, error) {
var hwnd syscall.Handle
cb := syscall.NewCallback(func(h syscall.Handle, p uintptr) uintptr {
b := make([]uint16, 200)
_, err := GetWindowText(h, &b[0], int32(len(b)))
if err != nil {
// ignore the error
return 1 // continue enumeration
}
if syscall.UTF16ToString(b) == title {
// note the window
hwnd = h
return 0 // stop enumeration
}
return 1 // continue enumeration
})
EnumWindows(cb, 0)
if hwnd == 0 {
return 0, fmt.Errorf("No window with title '%s' found", title)
}
return hwnd, nil
}
func main() {
const title = "Application Title"
h, err := FindWindow(title)
if err != nil {
log.Fatal(err)
}
fmt.Printf("Found '%s' window: handle=0x%x\n", title, h)
}
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