How to only show certain parts with CSS for Print?

问题:

I have a page with lots of data, tables and content. I want to make a print version that will only display very few selected things.

Instead of writing another page just for printing, I was reading about CSS's feature for "@media print".

First, what browsers support it? Since this is an internal feature, it's OK if only the latest browsers support it.

I was thinking of tagging a few DOM elements with a "printable" class, and basically apply "display:none" to everything except those elements with the "printable" class. Is that doable?

How do I achieve this?

EDIT: This is what I have so far:

<style type="text/css">
@media print {
    * {display:none;}
    .printable, .printable > * {display:block;}
}
</style>

But it hides everything. How do I make those "printable" elements visible?

EDIT: Trying now the negative approach

<style type="text/css">
@media print {
    body *:not(.printable *) {display:none;}
}
</style>

This looks good in theory, however it doesn't work. Maybe "not" doesn't support advanced css ...

回答1:

Start here. But basically what you are thinking is the correct approach.

Thanks, Now my question is actually becoming: How do I apply CSS to a class AND ALL OF ITS DESCENDANT ELEMENTS? So that I can apply "display:block" to whatever is in the "printable" zones.

If an element is set to display:none; all its children will be hidden as well. But in any case. If you want a style to apply to all children of something else, you do the following:

.printable * {
   display: block;
}

That would apply the style to all children of the "printable" zone.

回答2:

Nearly all browsers support it. It might be advantageous to use the media attribute on the link tag.

Using display: none; in some of your rules would be an appropriate way to handle your situation.

回答3:

I got here because I was curious about printing a chart generated by chart.js. I wanted to just print the chart directly from the page (with a button that does a 'window.print') without all of the other content of the page.

So, I got closer by using the technique from the answer here: Why can't I override display property applied via an asterisk? .

You have to apply the 'asterisk' to the 'body' element, not just by itself. So, using the example CSS that the OP (Nathan) added to the question, I changed it to this:

<style type="text/css">
@media print {
    body * {display:none;}
    .printable, .printable > * {
    display: block !important;
  }
}

Then adding that 'printable' class to the chart itself, as in

<canvas id="myChart" class="printable" width="400" height="400"></canvas>

Which removed all page elements on the printed output except the chart when the 'print' button is clicked (via this):

<script>
    myChart.render();
    document.getElementById("printChart").addEventListener("click",function(){
        window.print();
    });     
</script>

So, perhaps this will help anyone that gets to this question via the googles.

回答4:

A simple way:

<style>
    .print-only{
        display: none;
    }

    @media print {
        .no-print {
            display: none;
        }

        .print-only{
            display: block;
        }
}
</style>

回答5:

I suggest to hide the element that you won't print:

HTML

<h1 class="no-print" >Welcome Just Screen</h1>
<div> I want print this section :)</div>
<div class="no-print">It's display only on screen</div>

CSS

@media print {     
    .no-print {
        display: none;
    }
}