发送带字符串的javascript数组到php动作

I want to send an array with image strings to my php action. This is what I do so far:

$('#savepdf').click(function() {
    var imagesarray = new Array();
    var count = 4;
    var quizid = <?php echo json_encode($quizid); ?>;
    for (var i=0; i<count; i++)
    {
        var chart = Highcharts.charts[i];
        var canvasname;
        if(i == 0){
            canvasname = "canvas";
        }
        else{
            canvasname = "canvas" + i;
        }

        // get highcharts
        canvg(document.getElementById(canvasname), chart.getSVG())

        var canvas = document.getElementById(canvasname);
        var img = canvas.toDataURL("image/png");

        imagesarray[i] = img;
    }

    imagesarray = JSON.stringify(imagesarray);

    // AJAX CALL TO ACTION
    $.download('/results/savepdf','quizid=' + quizid + '&image=' + imagesarray);
});

The array that I send looks like this:

["data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAlgAAAGQCAYAAAByNR6YAAAgAElEQ…197b1kPfJ5y3guHO4WLEyAAAECBAgcEFjz7y+zZJ6ttf8GC0YA4ro/bucAAAAASUVORK5CYII=","data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAlgAAAGQCAYAAAByNR6YAAAgAElEQ…9v2cl0YeqeBTqMAAIIIIAAAgMINO3aT3a+sfNxGIa7fwBwOTGmIk2OYgAAAABJRU5ErkJggg==","data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAlgAAAGQCAYAAAByNR6YAAAgAElEQ…xdLNBhIkAEiAARIAJEIA8I7FRlf1T/XlD/hhcoUOCv/we6Hn4A9659wwAAAABJRU5ErkJggg==","data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAlgAAAGQCAYAAAByNR6YAAAgAElEQ…BdGOlYwAkjASSABJAAEkACBgm8UI89qf6sUX9GRIkS5cr/AFfL9D3Dad7CAAAAAElFTkSuQmCC"]

In my PHP action I do the following:

if(isset($_POST['quizid']))
     $quizid = $_POST['quizid'];
if(isset($_POST['image']))
     $image = $_POST['image'];

var_dump(json_decode($image));

The dump just shows "NULL". When I do this :

var_dump($image);

I just get : string(1) "["

Try to:

imagesarray = encodeURIComponent( JSON.stringify(imagesarray) );

UPDATE

and in php use

$image = json_decode(urldecode($_POST['image']));

I'm not familiar with the $.download method. Presumably it is an AJAX extension that allows for file downloads. I can guess how it probably works.

The problem is that you are not sending a valid HTTP request. JSON needs to be escaped to be sent over HTTP. You could do this yourself using encodeURIComponent, or you could let jQuery's $.param method handle it for you.

var data = $.param({
    quizid: quizid,
    image: imagesarray
});
$.download('/results/savepdf', data);