逆风天 发表于 2021-12-18 09:37:57

提取 Bootstrap 5 中的 自适应(Breakpoints)

本帖最后由 逆风天 于 2021-12-18 10:00 编辑

提取 Bootstrap 5 中的 自适应(Breakpoints)
在最新的 Bootstrap 5.* 中 他们加入了 6种分辨率的自适应样式。
当你不想自己写,又想用他们的自适应,又不想用其他的组件样式,那怎么办呢?
下面我们来一步一步的提取他们的自适应样式。

注意:本教程,需要在你有一定的 scss 基础的情况下进行!

原料:需要在 Bootstrap官网 下载 最新 源码包。

步骤:
1、新建一个 _breakpoints.scss 备用。

2、获取分辨率属性,在文件 scss\_variables.scss 中搜索,如下:
$grid-breakpoints: (
xs: 0,
sm: 576px,
md: 768px,
lg: 992px,
xl: 1200px,
xxl: 1400px
) !default;复制进 _breakpoints.scss。

3、再获取自适应的 mixin,在文件 scss\mixins\_breakpoints.scss ,将内部的代码复制到我们新建备用的 _breakpoints.scss 中。看起来如下:
// scss-docs-start grid-breakpoints
$grid-breakpoints: (
xs: 0,
sm: 576px,
md: 768px,
lg: 992px,
xl: 1200px,
xxl: 1400px
) !default;

// Breakpoint viewport sizes and media queries.
//
// Breakpoints are defined as a map of (name: minimum width), order from small to large:
//
//    (xs: 0, sm: 576px, md: 768px, lg: 992px, xl: 1200px)
//
// The map defined in the `$grid-breakpoints` global variable is used as the `$breakpoints` argument by default.

// Name of the next breakpoint, or null for the last breakpoint.
//
//    >> breakpoint-next(sm)
//    md
//    >> breakpoint-next(sm, (xs: 0, sm: 576px, md: 768px, lg: 992px, xl: 1200px))
//    md
//    >> breakpoint-next(sm, $breakpoint-names: (xs sm md lg xl))
//    md
@function breakpoint-next($name, $breakpoints: $grid-breakpoints, $breakpoint-names: map-keys($breakpoints)) {
$n: index($breakpoint-names, $name);
@if not $n {
    @error "breakpoint `#{$name}` not found in `#{$breakpoints}`";
}
@return if($n < length($breakpoint-names), nth($breakpoint-names, $n + 1), null);
}

// Minimum breakpoint width. Null for the smallest (first) breakpoint.
//
//    >> breakpoint-min(sm, (xs: 0, sm: 576px, md: 768px, lg: 992px, xl: 1200px))
//    576px
@function breakpoint-min($name, $breakpoints: $grid-breakpoints) {
$min: map-get($breakpoints, $name);
@return if($min != 0, $min, null);
}

// Maximum breakpoint width.
// The maximum value is reduced by 0.02px to work around the limitations of
// `min-` and `max-` prefixes and viewports with fractional widths.
// See https://www.w3.org/TR/mediaqueries-4/#mq-min-max
// Uses 0.02px rather than 0.01px to work around a current rounding bug in Safari.
// See https://bugs.webkit.org/show_bug.cgi?id=178261
//
//    >> breakpoint-max(md, (xs: 0, sm: 576px, md: 768px, lg: 992px, xl: 1200px))
//    767.98px
@function breakpoint-max($name, $breakpoints: $grid-breakpoints) {
$max: map-get($breakpoints, $name);
@return if($max and $max > 0, $max - .02, null);
}

// Returns a blank string if smallest breakpoint, otherwise returns the name with a dash in front.
// Useful for making responsive utilities.
//
//    >> breakpoint-infix(xs, (xs: 0, sm: 576px, md: 768px, lg: 992px, xl: 1200px))
//    ""(Returns a blank string)
//    >> breakpoint-infix(sm, (xs: 0, sm: 576px, md: 768px, lg: 992px, xl: 1200px))
//    "-sm"
@function breakpoint-infix($name, $breakpoints: $grid-breakpoints) {
@return if(breakpoint-min($name, $breakpoints) == null, "", "-#{$name}");
}

// Media of at least the minimum breakpoint width. No query for the smallest breakpoint.
// Makes the @content apply to the given breakpoint and wider.
@mixin media-breakpoint-up($name, $breakpoints: $grid-breakpoints) {
$min: breakpoint-min($name, $breakpoints);
@if $min {
    @media (min-width: $min) {
      @content;
    }
} @else {
    @content;
}
}

// Media of at most the maximum breakpoint width. No query for the largest breakpoint.
// Makes the @content apply to the given breakpoint and narrower.
@mixin media-breakpoint-down($name, $breakpoints: $grid-breakpoints) {
$max: breakpoint-max($name, $breakpoints);
@if $max {
    @media (max-width: $max) {
      @content;
    }
} @else {
    @content;
}
}

// Media that spans multiple breakpoint widths.
// Makes the @content apply between the min and max breakpoints
@mixin media-breakpoint-between($lower, $upper, $breakpoints: $grid-breakpoints) {
$min: breakpoint-min($lower, $breakpoints);
$max: breakpoint-max($upper, $breakpoints);

@if $min != null and $max != null {
    @media (min-width: $min) and (max-width: $max) {
      @content;
    }
} @else if $max == null {
    @include media-breakpoint-up($lower, $breakpoints) {
      @content;
    }
} @else if $min == null {
    @include media-breakpoint-down($upper, $breakpoints) {
      @content;
    }
}
}

// Media between the breakpoint's minimum and maximum widths.
// No minimum for the smallest breakpoint, and no maximum for the largest one.
// Makes the @content apply only to the given breakpoint, not viewports any wider or narrower.
@mixin media-breakpoint-only($name, $breakpoints: $grid-breakpoints) {
$min:breakpoint-min($name, $breakpoints);
$next: breakpoint-next($name, $breakpoints);
$max:breakpoint-max($next);

@if $min != null and $max != null {
    @media (min-width: $min) and (max-width: $max) {
      @content;
    }
} @else if $max == null {
    @include media-breakpoint-up($name, $breakpoints) {
      @content;
    }
} @else if $min == null {
    @include media-breakpoint-down($next, $breakpoints) {
      @content;
    }
}
}


4、下面就可以直接使用了。使用方法如下:.custom-class {
display: none;
}
@include media-breakpoint-up(sm) {
.custom-class {
    display: block;
}
}
5、其他。支持的分辨率如下:
// 分辨率宽度小于576px      <576px
@include media-breakpoint-up(xs) { ... }
// 分辨率宽度大于等于576px      ≥576px
@include media-breakpoint-up(sm) { ... }
// 分辨率宽度大于等于768px      ≥768px
@include media-breakpoint-up(md) { ... }
// 分辨率宽度大于等于992px      ≥992px
@include media-breakpoint-up(lg) { ... }
// 分辨率宽度大于等于1200px      ≥1200px
@include media-breakpoint-up(xl) { ... }
// 分辨率宽度大于等于1400px      ≥1400px
@include media-breakpoint-up(xxl) { ... }
6、还有 media-breakpoint-down、media-breakpoint-between、media-breakpoint-only等这些,这个就你自己去实践了,当然你也可以去 Bootstrap官网 查看文档使用。

祝,愉快使用!

页: [1]
查看完整版本: 提取 Bootstrap 5 中的 自适应(Breakpoints)