Win32::Screenshot

require 'win32/screenshot'

# Take a screenshot of the window with the specified title
Win32::Screenshot::Take.of(:window, title: "Windows Internet Explorer").write("image.bmp")

# Take a screenshot of the whole desktop area, including all monitors if multiple are connected
Win32::Screenshot::Take.of(:desktop).write("image.png")

# Take a screenshot of the foreground window
Win32::Screenshot::Take.of(:foreground).write("image.png")

# Take a screenshot of the foreground window, and writing over previous image if it exists
Win32::Screenshot::Take.of(:foreground).write!("image.png")

# Take a screenshot of the specified window with title matching the regular expression
Win32::Screenshot::Take.of(:window, title: /internet/i).write("image.jpg")

# Take a screenshot of the window with the specified handle
Win32::Screenshot::Take.of(:window, hwnd: 123456).write("image.gif")

# Take a screenshot of the child window with the specified internal class name
Win32::Screenshot::Take.of(
  :rautomation,
  RAutomation::Window.new(hwnd: 123456).child(class: "Internet Explorer_Server")
).write("image.png")

# Use the bitmap blob for something else
image = Win32::Screenshot::Take.of(:window, hwnd: 123456)
image.height # => height of the image
image.width  # => width of the image
image.bitmap # => bitmap blob