效果原理
主要利用css漸變實現一些不需要切圖的背景鏤空
優惠券樣式
.mixinsTicket(@width, @height, @r, @left, @lcolor, @rcolor) { width: @width; height: @height; background: radial-gradient(circle at top right, transparent @r, @lcolor 0) -(@width - @left) top ~'/' 100% 51% no-repeat, radial-gradient(circle at bottom right, transparent @r, @lcolor 0) -(@width - @left) bottom ~'/' 100% 51% no-repeat, radial-gradient(circle at top left, transparent @r, @rcolor 0) @left 0 ~'/' 100% 51% no-repeat, radial-gradient(circle at bottom left, transparent @r, @rcolor 0) @left bottom ~'/' 100% 51% no-repeat;}
.mixinsTicket1(@width, @height, @r, @top, @color) { width: @width; height: @height; background: radial-gradient(circle at bottom left, transparent @r, @color 0) left (@top - @height) ~'/' 51% 100% no-repeat, radial-gradient(circle at top left, transparent @r, @color 0) left @top ~'/' 51% 100% no-repeat, radial-gradient(circle at bottom right, transparent @r, @color 0) right (@top - @height) ~'/' 51% 100% no-repeat, radial-gradient(circle at top right, transparent @r, @color 0) right @top ~'/' 51% 100% no-repeat; &::after{ content: ''; display: block; position: absolute; width: calc(100% - 2 * @r); left: @r; top: @top; border-top: 1px dashed #fff; transform: translateY(.5); }}切角效果
ps: 鋸齒跟設備的顯示有關系
.mixinFlag(@width, @height, @bg) when(default()) { width: @width; height: @height; background: linear-gradient(45deg, transparent sqrt(pow(@width/2, 2)/2), @bg 0) right, linear-gradient(-45deg, transparent sqrt(pow(@width/2, 2)/2), @bg 0) left; background-size: 50% 100%; background-repeat: no-repeat; } .mixinFlag(@width, @height, @bg) when(@width > @height) { width: @width; height: @height; background: linear-gradient(-45deg, transparent sqrt(pow(@height/2, 2)/2), @bg 0) top left, linear-gradient(-135deg, transparent sqrt(pow(@height/2, 2)/2), @bg 0) bottom left; background-size: 100% 50%; background-repeat: no-repeat;}
.mixinsMark(@width, @height, @bg) { width: @width; height: @height; background: linear-gradient(-45deg, transparent sqrt(pow(@height/2, 2)/2), @bg 0) bottom left, linear-gradient(-135deg, transparent sqrt(pow(@height/2, 2)/2), @bg 0) top left; background-size: 100% 50%; background-repeat: no-repeat;}ps:以上效果四個方向都可以實現，其他方向代碼沒有貼出，原理相同
格子布
css { width: 510px; height: 128px; background: #FFF; background-image: linear-gradient(rgba(182, 128, 102, .8) 8px, transparent 0), linear-gradient(90deg, rgba(182, 128, 102, .8) 8px, transparent 0); background-size: 8px 14px, 14px 8px;}焦點
.mask { position: fixed; top: 0; left: 0; z-index: 100; width: 100vw; height: 100vh; background: radial-gradient(closest-side at 50% 278rpx, transparent 140rpx, rgba(0, 0, 0, .12) 180rpx, rgba(0, 0, 0, .22) 200rpx, rgba(0,0,0,.3) 220rpx, rgba(0,0,0, .4)) no-repeat;}總結
每一層漸變都可被當做一張背景圖，也就是說每一層漸變都可以指定其position、size、repeat。玩過PS的的同學應該知道圖層的概念，咱們的背景圖層疊原理也類似（當然，漸變也可以當背景圖），控制漸變的大小，哪里需要鏤空，以及需要顯示的位置、是否平鋪，就可以實現大多數場景下的基本效果，當然，一張切圖來的更快，但是有時候切圖并不能適應所有的場景。
掌握background的書寫順序可以幫助在腦海中構思自己想要的效果：
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