Question

在我的HTML文档中编写javascript时遇到问题，而在页面完全加载之前没有运行脚本。我已经将代码剥离到非常基本，以试图消除我可能做错的一切。我希望在函数init()运行之前加载页面并使用window.onload来执行此操作。但是，函数的警报在页面加载之前运行。无论我将脚本放在头部还是正文中，都会发生这种情况。我有什么不对的？提前谢谢！

<!doctype html>
<html lang="en">
<head>
    <meta charset="utf-8">
</head>
<body>

    <h1>Green Planet</h1>
    <p id="greenplanet">All is well</p>

    <h1>Red Planet</h1>
    <p >Nothing to report</p>

    <h1 >Blue Planet</h1>
    <p >All systems A-OK</p>

    <script>
        function init() {
            var planet = document.getElementById("greenplanet");
            planet.innerText = "Red Alert: hit by phaser fire!";
            planet.setAttribute("class","redtext");
            alert("it initialized");
        }
        window.onload=init;
    </script>
</body>
</html>

Answer 1

你的意思是你希望在执行函数之前完全渲染页面吗？如果是这样，您可以在调用byte[]时将函数体包裹起来。例如，在执行函数之前，这将完全呈现页面一秒钟：

/**
 * Use an order-n de-Bruijn sequence to fill a byte array such that no n-length sub-array is repeated.
 */
public static void trucatedDeBruijnBytes(int n, byte[] arr) {
    int written = generateLyndonBytes(1, 1, 256, new byte[n + 1], arr, 0);
    if (written != arr.length) {
        throw new RuntimeException("Can't generate a unique sequence of length " + arr.length + ", max is " + written);
    }
}

private static int generateLyndonBytes(int t, int p, int k, byte[] a, byte[] output, int oidx) {
    if (t == a.length) {
        if((a.length-1)%p==0) {
            int len = Math.min(p, output.length - oidx);
            System.arraycopy(a, 1, output, oidx, len);
            oidx += len;
        }
    } else {
        a[t] = a[t-p]; 
        assert a[t] < k;
        if ((oidx = generateLyndonBytes(t+1,p, k, a, output, oidx)) == output.length) {
            return oidx;
        }
        for(int j = (a[t-p] & 0xFF) + 1; j < k; j++) {
            assert(j >= 0 && j < k);
            a[t] = (byte)j;
            assert a[t] < k;
            if ((oidx = generateLyndonBytes(t+1,t, k, a, output, oidx)) == output.length) {
                return oidx;
            }
        }
    }
    return oidx;
}

window.onload在脚本运行之前不加载正文

1 个答案: