Determine whether browser supports printing

问题

I think the answer to this is almost certainly "no", because I've done a little testing and searching around, but is there any trick to detect whether window.print() even might work from inside a page (i.e., from JavaScript)? I know that even on a desktop/laptop it's never going to be possible to know whether there's a printer configured on the system, for example, but at least the browser will put up a print dialog.

My Android phone has a window.print() function but it (unsurprisingly) doesn't do anything.

Again I'm asking mostly so there's a good question on the topic at SO :-)

回答1:

Unfortunately it looks like a no. The window.print() function is not part of the EMCAScript specification. This means that there's no requirement for it to be part of the JavaScript language, and no proper documentation for its implementation. It's undefined behaviour and so testing for it looks very difficult.

Sources:

• https://developer.mozilla.org/en/DOM/window.print
• http://www.ecma-international.org/publications/files/ECMA-ST/Ecma-262.pdf

EDIT:

Cute little script I wrote to test my browsers, just checks the print function exists and then asks to print:

if(window.print) {
    if(confirm('I can print. Would you like to?'))
        window.print()
}

回答2:

The print() method is synchronous. This makes it possible to do the aftermath in order to decide wether a print dialog has been shown

var start = +new Date();
window.print();
var delta = + new Date() - start;
console.log(delta);
if (delta > 100) { console.log('It worked'); }

回答3:

The beforeprint and afterprint events may help, but I'm not sure about browser support.

Edit: Webkit does not support them

来源：https://stackoverflow.com/questions/9268840/determine-whether-browser-supports-printing