组件封装

// src/assets/styles/hairline.scss

@mixin scale-hairline-common($color, $top, $right, $bottom, $left) {
  content: '';
  position: absolute;
  display: block;
  z-index: 1;
  top: $top;
  right: $right;
  bottom: $bottom;
  left: $left;
  background-color: $color;
}


@mixin hairline($direction, $color: #000, $radius: 0) {
  @if $direction == top {
    border-top: 1px solid $color;

    // min-resolution 用来检测设备的最小像素密度
    @media (min-resolution: 2dppx) {
      border-top: none;

      &::before {
        @include scale-hairline-common($color, 0, auto, auto, 0);
        width: 100%;
        height: 1px;
        transform-origin: 50% 50%;
        transform: scaleY(0.5);

        @media (min-resolution: 3dppx) {
          transform: scaleY(0.33);
        }
      }
    }
  } @else if $direction == right {
    border-right: 1px solid $color;

    @media (min-resolution: 2dppx) {
      border-right: none;

      &::after {
        @include scale-hairline-common($color, 0, 0, auto, auto);
        width: 1px;
        height: 100%;
        background: $color;
        transform-origin: 100% 50%;
        transform: scaleX(0.5);

        @media (min-resolution: 3dppx) {
          transform: scaleX(0.33);
        }
      }
    }
  } @else if $direction == bottom {
    border-bottom: 1px solid $color;

    @media (min-resolution: 2dppx) {
      border-bottom: none;

      &::after {
        @include scale-hairline-common($color, auto, auto, 0, 0);
        width: 100%;
        height: 1px;
        transform-origin: 50% 100%;
        transform: scaleY(0.5);

        @media (min-resolution: 3dppx) {
          transform: scaleY(0.33);
        }
      }
    }
  } @else if $direction == left {
    border-left: 1px solid $color;

    @media (min-resolution: 2dppx) {
      border-left: none;

      &::before {
        @include scale-hairline-common($color, 0, auto, auto, 0);
        width: 1px;
        height: 100%;
        transform-origin: 100% 50%;
        transform: scaleX(0.5);

        @media (min-resolution: 3dppx) {
          transform: scaleX(0.33);
        }
      }
    }
  } @else if $direction == all {
    border: 1px solid $color;
    border-radius: $radius;

    @media (min-resolution: 2dppx) {
      position: relative;
      border: none;

      &::before {
        content: '';
        position: absolute;
        left: 0;
        top: 0;
        width: 200%;
        height: 200%;
        border: 1px solid $color;
        border-radius: $radius * 2;
        transform-origin: 0 0;
        transform: scale(0.5);
        box-sizing: border-box;
        pointer-events: none;
      }
    }
  }
}

// 移除边框
@mixin hairline-remove($position: all) {
  @if $position == left {
    border-left: 0;
    &::before {
      display: none !important;
    }
  } @else if $position == right {
    border-right: 0;
    &::after {
      display: none !important;
    }
  } @else if $position == top {
    border-top: 0;
    &::before {
      display: none !important;
    }
  } @else if $position == bottom {
    border-bottom: 0;
    &::after {
      display: none !important;
    }
  } @else if $position == all {
    border: 0;
    &::before {
      display: none !important;
    }
    &::after {
      display: none !important;
    }
  }
}

使用格式

在某个scss文件中：

1. 导入。导入上面封装的hairline.scss
2. 使用：给某个选择器添加1px边框

选择器{
  @include hairline(参数，xxxx)
}

@import '~@scss/hairline.scss';

.box1 {
  margin: 10px 0;
  position:relative;
  @include hairline(bottom, #000); // 添加边框
  @include hairline-remove(bottom); // 移除边框
}