我想設計一個名爲add-frame的函數,它需要一個圖像,並在所有四邊都用一個像素的黑色邊框包圍它。這裏是我所擁有的:覆蓋在方案(球拍)
(define (horizontal-line x)
(line x 0 "black"))
(define (vertical-line x)
(line 0 x "black"))
(define (add-left-border height design color)
(overlay/align "left" "top"
(vertical-line height)
(square height design color)))
(define (add-right-border height design color)
(overlay/align "right" "top"
(vertical-line height)
(square height design color)))
(define (add-top-border height design color)
(overlay/align "right" "top"
(horizontal-line height)
(square height design color)))
(define (add-bottom-border height design color)
(overlay/align "right" "bottom"
(horizontal-line height)
(square height design color)))
(define (add-frame height design color)
(overlay (square height design color)
(add-left-border height design color)
(add-right-border height design color)
(add-top-border height design color)
(add-bottom-border height design color)))
當我運行「添加框架」時,我返回一個帶有左邊框的正方形圖像。如何讓邊框的其餘部分出現在返回的廣場上?
您可以點擊標籤下方的「編輯」按鈕編輯您的帖子。 –
出於好奇,這是一個功課題嗎? –
如何定義「垂直線」和「水平線」? (我無法讓你的程序運行) – soegaard