dta25920 2013-06-16 04:37
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在页面加载时显示来自php的json canvas图像

I am trying to recreate a signature in a canvas when the page loads. I have managed to capture a signature and store it in a MySQL database using PHP. It is stored as json data. Now the problem is this: I have a page with a canvas element and I can retrieve the json data from the database before the page loads using php but I do not know how to pass this data to the canvas element. Hoping for a solution because I have spent too many hours messing this up. Thank you!

json data:

"[
   {
      \"lx\":87,
      \"ly\":6,
      \"mx\":87,
      \"my\":5
   },
   {
      \"lx\":88,
      \"ly\":5,
      \"mx\":87,
      \"my\":6
   },
   {
      \"lx\":89,
      \"ly\":6,
      \"mx\":88,
      \"my\":5
   },
   {
      \"lx\":89,
      \"ly\":7,
      \"mx\":89,
      \"my\":6
   },
   {
      \"lx\":90,
      \"ly\":7,
      \"mx\":89,
      \"my\":7
   },
   {
      \"lx\":90,
      \"ly\":8,
      \"mx\":90,
      \"my\":7
   },
   {
      \"lx\":90,
      \"ly\":10,
      \"mx\":90,
      \"my\":8
   },
   {
      \"lx\":91,
      \"ly\":11,
      \"mx\":90,
      \"my\":10
   },
   {
      \"lx\":92,
      \"ly\":11,
      \"mx\":91,
      \"my\":11
   },
   {
      \"lx\":92,
      \"ly\":12,
      \"mx\":92,
      \"my\":11
   },
   {
      \"lx\":93,
      \"ly\":12,
      \"mx\":92,
      \"my\":12
   },
   {
      \"lx\":93,
      \"ly\":13,
      \"mx\":93,
      \"my\":12
   },
   {
      \"lx\":95,
      \"ly\":15,
      \"mx\":93,
      \"my\":13
   },
   {
      \"lx\":96,
      \"ly\":16,
      \"mx\":95,
      \"my\":15
   },
   {
      \"lx\":97,
      \"ly\":16,
      \"mx\":96,
      \"my\":16
   },
   {
      \"lx\":97,
      \"ly\":17,
      \"mx\":97,
      \"my\":16
   },
   {
      \"lx\":98,
      \"ly\":18,
      \"mx\":97,
      \"my\":17
   },
   {
      \"lx\":99,
      \"ly\":18,
      \"mx\":98,
      \"my\":18
   },
   {
      \"lx\":99,
      \"ly\":19,
      \"mx\":99,
      \"my\":18
   },
   {
      \"lx\":99,
      \"ly\":20,
      \"mx\":99,
      \"my\":19
   },
   {
      \"lx\":102,
      \"ly\":5,
      \"mx\":102,
      \"my\":4
   },
   {
      \"lx\":101,
      \"ly\":5,
      \"mx\":102,
      \"my\":5
   },
   {
      \"lx\":101,
      \"ly\":6,
      \"mx\":101,
      \"my\":5
   },
   {
      \"lx\":100,
      \"ly\":7,
      \"mx\":101,
      \"my\":6
   },
   {
      \"lx\":100,
      \"ly\":8,
      \"mx\":100,
      \"my\":7
   },
   {
      \"lx\":99,
      \"ly\":8,
      \"mx\":100,
      \"my\":8
   },
   {
      \"lx\":99,
      \"ly\":9,
      \"mx\":99,
      \"my\":8
   },
   {
      \"lx\":98,
      \"ly\":9,
      \"mx\":99,
      \"my\":9
   },
   {
      \"lx\":98,
      \"ly\":10,
      \"mx\":98,
      \"my\":9
   },
   {
      \"lx\":97,
      \"ly\":11,
      \"mx\":98,
      \"my\":10
   },
   {
      \"lx\":96,
      \"ly\":12,
      \"mx\":97,
      \"my\":11
   },
   {
      \"lx\":95,
      \"ly\":12,
      \"mx\":96,
      \"my\":12
   },
   {
      \"lx\":94,
      \"ly\":12,
      \"mx\":95,
      \"my\":12
   },
   {
      \"lx\":93,
      \"ly\":12,
      \"mx\":94,
      \"my\":12
   },
   {
      \"lx\":91,
      \"ly\":13,
      \"mx\":93,
      \"my\":12
   },
   {
      \"lx\":89,
      \"ly\":14,
      \"mx\":91,
      \"my\":13
   },
   {
      \"lx\":89,
      \"ly\":15,
      \"mx\":89,
      \"my\":14
   },
   {
      \"lx\":88,
      \"ly\":15,
      \"mx\":89,
      \"my\":15
   },
   {
      \"lx\":87,
      \"ly\":16,
      \"mx\":88,
      \"my\":15
   },
   {
      \"lx\":86,
      \"ly\":17,
      \"mx\":87,
      \"my\":16
   },
   {
      \"lx\":86,
      \"ly\":18,
      \"mx\":86,
      \"my\":17
   },
   {
      \"lx\":85,
      \"ly\":18,
      \"mx\":86,
      \"my\":18
   },
   {
      \"lx\":85,
      \"ly\":19,
      \"mx\":85,
      \"my\":18
   },
   {
      \"lx\":85,
      \"ly\":20,
      \"mx\":85,
      \"my\":19
   },
   {
      \"lx\":84,
      \"ly\":20,
      \"mx\":85,
      \"my\":20
   }
]"
  • 写回答

1条回答 默认 最新

  • douju2053 2013-06-16 04:49
    关注

    You have 2 options:

    Echo into a javascript variable when you generate the page:

    echo "<script>var sig = ".$jsonsig.";</script>";
    

    or retrieve it after the page has loaded with an AJAX call

    (jQuery in your page script, requires a PHP script to return the JSON code)

    $.getJSON("getmysig.php",function(data) {
    // create canvas here
    });
    
    本回答被题主选为最佳回答 , 对您是否有帮助呢?
    评论

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