我可以给 Col-md-1.5在引导？

The short answer is no (technically you can give whatever name of the class you want, but this will have no effect, unless you define your own CSS class - and remember - no dots in the class selector). The long answer is again no, because Bootstrap includes a responsive, mobile first fluid grid system that appropriately scales up to 12 columns as the device or view port size increases.

Rows must be placed within a .container (fixed-width) or .container-fluid (full-width) for proper alignment and padding.

• Use rows to create horizontal groups of columns.
• Content should be placed within columns, and only columns may be immediate children of rows.
• Predefined grid classes like .row and .col-xs-4 are available for quickly making grid layouts. Less mixins can also be used for more semantic layouts.
• Columns create gutters (gaps between column content) via padding. That padding is offset in rows for the first and last column via negative margin on .rows.
• Grid columns are created by specifying the number of twelve available columns you wish to span. For example, three equal columns would use three .col-xs-4.
• If more than 12 columns are placed within a single row, each group of extra columns will, as one unit, wrap onto a new line.
• Grid classes apply to devices with screen widths greater than or equal to the breakpoint sizes, and override grid classes targeted at smaller devices. Therefore, e.g. applying any .col-md-* class to an element will not only affect its styling on medium devices but also on large devices if a .col-lg-* class is not present.

A possible solution to your problem is to define your own CSS class with desired width, let's say .col-half{width:XXXem !important} then add this class to elements you want along with original Bootstrap CSS classes.

This is not Bootstrap Standard to give col-md-1.5 and you can not edit bootstrap.min.css because is not right way. you can create like this http://www.bootply.com/125259

As @bodi0 correctly said, it is not possible. You either have to extent Bootstrap's grid system (you can search and find various solutions, here is a 7-column example) or use nested rows e.g. http://bootply.com/dd50he9tGe.

In the case of nested rows you might not always get the exact result but a similar one

<div class="row">
<div class="col-lg-5">
<div class="row">
<div class="col-lg-4">1.67 (close to 1.5)</div>
<div class="col-lg-8">3.33 (close to 3.5)</div>
</div>
</div>
<div class="col-lg-7">
<div class="row">
<div class="col-lg-6">3.5</div>
<div class="col-lg-6">3.5</div>
</div>
</div>
</div>

You cloud also simply override the width of the Column...

<div class="col-md-1" style="width: 12.499999995%"></div>

Since col-md-1 is of width 8.33333333%; simply multiply 8.33333333 * 1.5 and set it as your width.

in bootstrap 4, you will have to override flex and max-width property too:

<div class="col-md-1" style="width: 12.499999995%;
flex: 0 0 12.499%;max-width: 12.499%;"></div>

Create new classes to overwrite the width. See jFiddle for working code.

<div class="row">
<div class="col-xs-1 col-xs-1-5">
<div class="box">
box 1
</div>
</div>
<div class="col-xs-3 col-xs-3-5">
<div class="box">
box 2
</div>
</div>
<div class="col-xs-3 col-xs-3-5">
<div class="box">
box 3
</div>
</div>
<div class="col-xs-3 col-xs-3-5">
<div class="box">
box 4
</div>
</div>
</div>


.col-xs-1-5 {
width: 12.49995%;
}
.col-xs-3-5 {
width: 29.16655%;
}
.box {
border: 1px solid #000;
text-align: center;
}

As others mentioned in Bootstrap 3, you can use nest/embed techniques.

However it is becoming more obvious to use pretty awesome feature from Bootstrap 4 now. you simple have the option to use the col-{breakpoint}-auto classes (e.g. col-md-auto) to make columns size itself automatically based on the natural width of its content. check this for example

This question is quite old, but I have made it that way (in TYPO3).

Firstly, I have made a own accessible css-class which I can choose on every content element manually.

Then, I have made a outer three column element with 11 columns (1 - 9 - 1), finally, I have modified the column width of the first and third column with CSS to 12.499999995%.

Bootstrap 4 uses flex-box and you can create your own column definitions

This is close to a 1.5, tweak to your own needs.

.col-1-5 {
flex: 0 0 12.3%;
max-width: 12.3%;
position: relative;
width: 100%;
padding-right: 15px;
padding-left: 15px;
}

you can use this code inside col-md-3 , col-md-9

.col-side-right{
flex: 0 0 20% !important;
max-width: 20%;
}


.col-side-left{
flex: 0 0 80%;
max-width: 80%;
}

According to Rex Bloom response I have write a bootstrap helper:

//8,33333333% col-1


.extra-col {
position: relative;
width: 100%;
padding-right: 15px;
padding-left: 15px;
}


.col-0-5 {
@extend .extra-col;
flex: 0 0 4.16666667%;
max-width: 4.16666667%;
}


.col-1-5 {
@extend .extra-col;
flex: 0 0 12.5%;
max-width: 12.5%;
}


.col-2-5 {
@extend .extra-col;
flex: 0 0 20.833333325%;
max-width: 20.833333325%;
}


.col-3-5 {
@extend .extra-col;
flex: 0 0 29.166666655%;
max-width: 29.166666655%;
}


.col-4-5 {
@extend .extra-col;
flex: 0 0 37.499999985%;
max-width: 37.499999985%;
}


.col-5-5 {
@extend .extra-col;
flex: 0 0 45.833333315%;
max-width: 45.833333315%;
}


.col-6-5 {
@extend .extra-col;
flex: 0 0 54.166666645%;
max-width: 54.166666645%;
}


.col-7-5 {
@extend .extra-col;
flex: 0 0 62.499999975%;
max-width: 62.499999975%;
}


.col-8-5 {
@extend .extra-col;
flex: 0 0 70.833333305%;
max-width: 70.833333305%;
}


.col-9-5 {
@extend .extra-col;
flex: 0 0 79.166666635%;
max-width: 79.166666635%;
}


.col-10-5 {
@extend .extra-col;
flex: 0 0 87.499999965%;
max-width: 87.499999965%;
}


.col-11-5 {
@extend .extra-col;
flex: 0 0 95.8333333%;
max-width: 95.8333333%;
}

Bootstrap has column offsets, so if you want columns with equal width without specifying size use this.

<div class="row">
<div class="col">col</div>
<div class="col">col</div>
<div class="col">col</div>
<div class="col">col</div>
</div>

Also check out this link https://getbootstrap.com/docs/4.0/layout/grid/#all-breakpoints

I have created a custom bootstrap extension that allows you to use the following classes:

// replace * with a number between 0 and 11
col-*-1qtr
col-*-half
col-*-3qtr

Also note that you can use responsive classes, such as:

• col-sm-2-half (2.5)
• col-md-0-3qtr (0.75)
• col-lg-11-1qtr (11.25)
• col-xl-5-half (5.5)

Here is an example:

<!DOCTYPE html>
<html lang="en">
<head>
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.5.2/css/bootstrap.min.css">
<link rel="stylesheet" href="https://cdn.jsdelivr.net/gh/hoomanbahreini/bootstrap-half-and-quarter-grid/fractional-grid.min.css">
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.16.0/umd/popper.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.5.2/js/bootstrap.min.js"></script>
</head>
<body>


<div class="container">
<h2>Using fraction of columns</h2>
<div class="row">
<div class="col-2-3qtr bg-success">col-2-3qtr (2.75)</div>
<div class="col-3-1qtr bg-warning">col-3-1qtr (3.25)</div>
<div class="col-3-half bg-success">col-3-half (3.5)</div>
<div class="col-2-half bg-warning">col-2-half (2.5)</div>
</div>
</div>


</body>
</html>