javascript get x and y coordinates on mouse click

问题

I have a little div tag that when I click it (onClick event), it will run the printMousePos() function. This is the HTML tags:

<html>
    <header>
        <!-- By the way, this is not the actual html file, just a generic example. -->
        <script src=\'game.js\'></script>
    </header>
    <body>
        <div id=\"example\">
            <p id=\"test\">x: , y:</p>
        </div>
    </body>
</html>

This is the printMousePos function in a seperate .js file:

function printMousePos() {
    var cursorX;
    var cursorY;
    document.onmousemove = function(e){
    cursorX = e.pageX;
    cursorY = e.pageY;
}
    document.getElementById(\'test\').innerHTML = \"x: \" + cursorX + \", y: \" + cursorY;
}

Yes, the function actually works (it knows when you click it and all), but it returns undefined for both x and y, so I\'m assuming that the get x and y code in the function is incorrect. Any Ideas? I also know there isn\'t any built in functions within javascript itself to return the x and y like in java, ex.. would there be a way to do it with say JQuery or php? (avoid those if possible though, javascript would be best). Thanks!

回答1:

Like this.

function printMousePos(event) {
  document.body.textContent =
    "clientX: " + event.clientX +
    " - clientY: " + event.clientY;
}

document.addEventListener("click", printMousePos);

MouseEvent - MDN

MouseEvent.clientX Read only
The X coordinate of the mouse pointer in local (DOM content) coordinates.

MouseEvent.clientY Read only
The Y coordinate of the mouse pointer in local (DOM content) coordinates.

回答2:

It sounds like your printMousePos function should:

Get the X and Y coordinates of the mouse
Add those values to the HTML

Currently, it does this:

Creates (undefined) variables for the X and Y coordinates of the mouse
Attaches a function to the "mousemove" event (which will set those variables to the mouse coordinates when triggered by a mouse move)
Adds the current values of your variables to the HTML

See the problem? Your variables are never getting set, because as soon as you add your function to the "mousemove" event you print them.

It seems like you probably don't need that mousemove event at all; I would try something like this:

function printMousePos(e) {
    var cursorX = e.pageX;
    var cursorY = e.pageY;
    document.getElementById('test').innerHTML = "x: " + cursorX + ", y: " + cursorY;
}

回答3:

simple solution is this:

game.js:

document.addEventListener('click', printMousePos, true);
function printMousePos(e){

      cursorX = e.pageX;
      cursorY= e.pageY;
      $( "#test" ).text( "pageX: " + cursorX +",pageY: " + cursorY );
}

来源：https://stackoverflow.com/questions/23744605/javascript-get-x-and-y-coordinates-on-mouse-click

标签

javascript

html

onclick

onmouseclick