Question

我想使用calc()计算网格模板中的行数，但是试图用除法获得repeat的计数是行不通的：

.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>

关于repeat，calc和除法一起工作的方式，我缺少什么吗？这是在Chrome 71.0.3578.98中。

Answer 1

与calc一起使用除法时，结果将是number而不是integer，因此将无法正常工作，因为repeat()期望interger

repeat()语法的通用形式大约为

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

和

在/处，检查右侧是否为<number>。如果左侧为<integer>，请解析为<number>。否则，请解析为左侧的类型。^ref

和

数字值用<number>表示，并表示实数，可能带有小数部分。^ref

即使我们俩都知道结果将是整数，浏览器仍会将其视为数字。

万一侧面有数字，您可能会遇到乘法问题

.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的行为有所不同，即使我们明确指定数字，Firefox也不会失败。在所有情况下，Fiferox都会尝试将calc()的结果四舍五入为正整数1。

以下所有示例在Chrome上均无法运行，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>

如何计算（）网格模板中的行数？

1 个答案: