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我正在尝试在页面上预加载的脚本中隐藏图像。

下面的脚本使图像在点击屏幕时“下雨”。它运行良好，但在单击按钮之前它会在页面上显示预加载的图像本身。我试图隐藏图像，直到按下按钮。

如果有人对如何在功能dispenseMittens() 运行之前隐藏图像有任何见解，我将永远感激不尽:)

谢谢！

<script language="javascript">
var pictureSrc = 'mitten.gif'; //the location of the mittens
var pictureWidth = 40;            //the width of the mittens
var pictureHeight = 46;           //the height of the  mittens
var numFlakes = 10;               //the number of  mittens
var downSpeed = 0.01;          
var lrFlakes = 10;         
var EmergencyMittens = false; 

//safety checks. Browsers will hang if this is wrong. If other values are wrong there will just be errors
if( typeof( numFlakes ) != 'number' || Math.round( numFlakes ) != numFlakes || numFlakes < 1 ) { numFlakes = 10; }

//draw the snowflakes
for( var x = 0; x < numFlakes; x++ ) {
    if( document.layers ) { //releave NS4 bug
        document.write('<layer id="snFlkDiv'+x+'"><img src="'+pictureSrc+'" height="'+pictureHeight+'" width="'+pictureWidth+'" alt="*" border="0"></layer>');
    } else {
        document.write('<div style="position:absolute;" id="snFlkDiv'+x+'"><img src="'+pictureSrc+'" height="'+pictureHeight+'" width="'+pictureWidth+'" alt="*" border="0"></div>');
    }
}

//calculate initial positions (in portions of browser window size)
var xcoords = new Array(), ycoords = new Array(), snFlkTemp;
for( var x = 0; x < numFlakes; x++ ) {
    xcoords[x] = ( x + 1 ) / ( numFlakes + 1 );
    do { snFlkTemp = Math.round( ( numFlakes - 1 ) * Math.random() );
    } while( typeof( ycoords[snFlkTemp] ) == 'number' );
    ycoords[snFlkTemp] = x / numFlakes;
}

//now animate
function mittensFall() {
    if( !getRefToDivNest('snFlkDiv0') ) { return; }
    var scrWidth = 0, scrHeight = 0, scrollHeight = 0, scrollWidth = 0;
    //find screen settings for all variations. doing this every time allows for resizing and scrolling
    if( typeof( window.innerWidth ) == 'number' ) { scrWidth = window.innerWidth; scrHeight = window.innerHeight; } else {
        if( document.documentElement && ( document.documentElement.clientWidth || document.documentElement.clientHeight ) ) {
            scrWidth = document.documentElement.clientWidth; scrHeight = document.documentElement.clientHeight; } else {
            if( document.body && ( document.body.clientWidth || document.body.clientHeight ) ) {
                scrWidth = document.body.clientWidth; scrHeight = document.body.clientHeight; } } }
    if( typeof( window.pageYOffset ) == 'number' ) { scrollHeight = pageYOffset; scrollWidth = pageXOffset; } else {
        if( document.body && ( document.body.scrollLeft || document.body.scrollTop ) ) { scrollHeight = document.body.scrollTop; scrollWidth = document.body.scrollLeft; } else {
            if( document.documentElement && ( document.documentElement.scrollLeft || document.documentElement.scrollTop ) ) { scrollHeight = document.documentElement.scrollTop; scrollWidth = document.documentElement.scrollLeft; } }
    }
    //move the snowflakes to their new position
    for( var x = 0; x < numFlakes; x++ ) {
        if( ycoords[x] * scrHeight > scrHeight - pictureHeight ) { ycoords[x] = 0; }
        var divRef = getRefToDivNest('snFlkDiv'+x); if( !divRef ) { return; }
        if( divRef.style ) { divRef = divRef.style; } var oPix = document.childNodes ? 'px' : 0;
        divRef.top = ( Math.round( ycoords[x] * scrHeight ) + scrollHeight ) + oPix;
        divRef.left = ( Math.round( ( ( xcoords[x] * scrWidth ) - ( pictureWidth / 2 ) ) + ( ( scrWidth / ( ( numFlakes + 1 ) * 4 ) ) * ( Math.sin( lrFlakes * ycoords[x] ) - Math.sin( 3 * lrFlakes * ycoords[x] ) ) ) ) + scrollWidth ) + oPix;
        ycoords[x] += downSpeed;
    }
}

//DHTML handlers
function getRefToDivNest(divName) {
    if( document.layers ) { return document.layers[divName]; } //NS4
    if( document[divName] ) { return document[divName]; } //NS4 also
    if( document.getElementById ) { return document.getElementById(divName); } //DOM (IE5+, NS6+, Mozilla0.9+, Opera)
    if( document.all ) { return document.all[divName]; } //Proprietary DOM - IE4
    return false;
}


function dispenseMittens() {
if (EmergencyMittens) {
 window.clearInterval(EmergencyMittens);

} else {
EmergencyMittens = window.setInterval('mittensFall();',100);
}
}
</script>
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1 回答 1

2

为什么不将图像的样式设置为display: 'none'直到单击按钮，然后您可以将样式设置回display: 'inline-block'下雨之前？

于 2012-11-15T22:56:29.080 回答