我在Firefox 33.0(Ubuntu 12.04)中遇到了這種奇怪的行爲:在代碼中出現一些錯誤之後,所有其他Firefox標籤都沒有顯示任何東西,我需要關閉Firefox並再次打開它。全局變量崩潰firefox
看起來像全局變量(NFilhos和SomaFilhos)沒有正確地存儲在函數之間?調整窗口大小後發生錯誤(因此在resizeCanvas函數中)。我的代碼減少到最低限度:
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Is this a bug?</title>
</head>
<body onload="start()" onresize="resizeCanvas()" style="overflow: hidden">
<canvas id="tree" style="border:1px solid #000000;">
Seu navegador não suporta o recurso "canvas" do HTML 5.
</canvas>
</body>
<script>
var canv = document.getElementById("tree");
var ctx = canv.getContext("2d");
var NFilhos = [];
var SomaFilhos = [];
function start() {
alert("start");
SomaFilhos[0] = 10;
// ... read text file from server, prepare data...
resizeCanvas(); // draws the data the first time
}
function resizeCanvas() {
alert("resize"); // just to see where I am
canv.width = window.innerWidth;
canv.height = window.innerHeight;
alert("no error"); // just to see where I am
NFilhos[0] = SomaFilhos[0]; // error?
//alert(NFilhos[0]);
}
</script>
</html>
我只是修改您的警報()來顯示'SomaFilhos [0]',它顯示爲10沒有問題 – Dinesh 2014-11-22 01:10:14
它在MacOS上在爲我工作的FFX-33,除了所有的變量名神祕葡萄牙語...... – Malvolio 2014-11-22 01:13:41
直接調用一個函數調整大小是一個壞主意(並且在它內部更多地使用'alert' - 使用'console.log'來代替調試輸出) - resize'事件觸發多次在調整窗口大小的過程中。你應該使用一種技術來延遲函數的執行,類似於這裏爲'scroll'事件描述的內容:http://ejohn.org/blog/learning-from-twitter/ – CBroe 2014-11-22 02:01:51