user-interface - 如何在 Racket GUI Toolkit 中的框架上添加图像？

Question

如何将图像(例如 png)添加到 frame% 对象上？

#lang racket
(define my-frame (new frame%))
;want to add an image to my-frame

Answer 1

使用 a canvas .

(define my-frame (new frame%
                      [label "Example"]
                      [width 300]
                      [height 300]))

(new canvas% 
     [parent my-frame]
     [paint-callback
      (λ (canvas dc)
        (send dc draw-bitmap (read-bitmap "/path/to/image.png") 0 0))])

(send my-frame show #t)