如何计算()网格模板中的行数？

Question

我想计算网格模板中使用的行数calc(),但是尝试repeat使用除法计数是不行的:

.grid {
  display: grid;
  grid-gap: 10px;
  grid-template-columns: 1fr;
  margin-bottom: 10px;
  background: rgba(0, 0, 0, 0.2);
}

.grid>div {
  background: tomato;
  width: 20px;
  text-align: center;
  margin: auto;
}

.grid.no-calc {
  grid-template-rows: repeat(3, 30px);
}

.grid.addition {
  grid-template-rows: repeat(calc(1 + 2), 30px);
}

.grid.subtraction {
  grid-template-rows: repeat(calc(4 - 1), 30px);
}

.grid.multiplication {
  grid-template-rows: repeat(calc(3 * 1), 30px);
}

.grid.division {
  grid-template-rows: repeat(calc(6 / 2), 30px);
}

<p>Top 4 have their row heights set correctly</p>

<div class="grid no-calc">
  <div>1</div>
  <div>2</div>
  <div>3</div>
</div>

<div class="grid addition">
  <div>1</div>
  <div>2</div>
  <div>3</div>
</div>

<div class="grid subtraction">
  <div>1</div>
  <div>2</div>
  <div>3</div>
</div>

<div class="grid multiplication">
  <div>1</div>
  <div>2</div>
  <div>3</div>
</div>

<p>Division doesn't work in setting row height</p>

<div class="grid division">
  <div>1</div>
  <div>2</div>
  <div>3</div>
</div>

是否有什么我失踪约的方式repeat,calc和师一起工作？这是在Chrome 71.0.3578.98中.

Answer 1

当使用除法时calc,结果将是a number而不是integer因此它将不起作用,因为repeat()期望ainterger

repeat()语法的通用形式大约是

repeat( [ <positive-integer> | auto-fill | auto-fit ] , <track-list> )^REF

和

在/,检查右侧是否<number>.如果是左侧<integer>,请解决<number>.否则,请解析为左侧的类型.^REF

和

数值由<number>和表示实数,可能带有小数分量.^REF

即使我们都知道结果将是一个整数,浏览器仍然会将其视为一个数字.

如果你在其中一个边有一个数字,你可以遇到相同的乘法问题

.grid {
  display: grid;
  grid-gap: 10px;
  grid-template-columns: 1fr;
  margin-bottom: 10px;
  background: rgba(0, 0, 0, 0.2);
}

.grid>div {
  background: tomato;
  width: 20px;
  text-align: center;
  margin: auto;
}

.grid.no-calc {
  grid-template-columns: repeat(3, 30px);
  border-bottom:3px solid red;
}

.grid.multiplication {
  grid-template-columns: repeat(calc(3 * 1.0), 30px); /*will fail*/
  border-bottom:calc(3px * 1.0) solid red;
}

.grid.division {
  grid-template-columns: repeat(calc(6 / 2), 30px);
  border-bottom:calc(6px / 2) solid red; /*this will work because border accept numbers*/
}

<div class="grid no-calc">
  <div>1</div>
  <div>2</div>
  <div>3</div>
</div>


<div class="grid multiplication">
  <div>1</div>
  <div>2</div>
  <div>3</div>
</div>

<div class="grid division">
  <div>1</div>
  <div>2</div>
  <div>3</div>
</div>

Firefox的行为方式不同,即使我们明确指定数字也永远不会失败.在所有情况下,Fiferox将尝试将结果舍入calc()为正整数1.

以下所有示例都将在Chrome上失败,并且可以在Firefox上运行:

.grid {
  display: grid;
  grid-gap: 10px;
  grid-template-columns: 1fr;
  margin-bottom: 10px;
  background: rgba(0, 0, 0, 0.2);
}

.grid>div {
  background: tomato;
  width: 20px;
  text-align: center;
  margin: auto;
}

.grid.no-calc {
  grid-template-columns: repeat(calc(2.8), 30px); /*will be converted to 3*/
  border-bottom:calc(calc(2.8) * 1px) solid red;
}

.grid.multiplication {
  grid-template-columns: repeat(calc(3 * 1.55), 30px);  /*will be converted to 4*/
  border-bottom:calc(calc(3 * 1.55) * 1px) solid red;
}

.grid.division {
  grid-template-columns: repeat(calc(6 / 2.8), 30px); /*will be converted to 2*/
  border-bottom:calc(calc(6 / 2.8) * 1px) solid red;
  
}

<div class="grid no-calc">
  <div>1</div>
  <div>2</div>
  <div>3</div>
  <div>4</div>
</div>


<div class="grid multiplication">
  <div>1</div>
  <div>2</div>
  <div>3</div>
  <div>4</div>
</div>

<div class="grid division">
  <div>1</div>
  <div>2</div>
  <div>3</div>
  <div>4</div>
</div>