不通过jQuery循环

Question

好吧，我只是无法弄清楚这一点。在查看并重新查看我的代码可能是几小时后，我仍然没有更接近发现这种奇怪的行为。

它与背景的褪色有关，并且它在数组中列出的图像中有12个左右。

正在离开的图像是：BG6，bg36，BG13，BG8，BG14，BG15，bg24，bg29，bg27，BG9，bg19，BG3

主代码第1部分：

insertLayer(); 

var bg1 = "#000 url('./images/background/image_1.jpg') no-repeat fixed center center"; 
var bg2 = "#000 url('./images/background/image_2.jpg') no-repeat fixed center center"; 
var bg3 = "#000 url('./images/background/image_3.jpg') no-repeat fixed center center"; 

var bg4 = "#000 url('./images/background/image_4.jpg') no-repeat fixed center center"; 
var bg5 = "#000 url('./images/background/image_5.jpg') no-repeat fixed center center"; 
var bg6 = "#000 url('./images/background/image_6.jpg') no-repeat fixed center center"; 

var bg7 = "#000 url('./images/background/image_7.jpg') no-repeat fixed center center"; 
var bg8 = "#000 url('./images/background/image_8.jpg') no-repeat fixed center center"; 
var bg9 = "#000 url('./images/background/image_9.jpg') no-repeat fixed center center"; 

var bg10 = "#000 url('./images/background/image_10.jpg') no-repeat fixed center center"; 
var bg11 = "#000 url('./images/background/image_11.jpg') no-repeat fixed center center"; 
var bg12 = "#000 url('./images/background/image_12.jpg') no-repeat fixed center center"; 

var bg13 = "#000 url('./images/background/image_13.jpg') no-repeat fixed center center"; 
var bg14 = "#000 url('./images/background/image_14.jpg') no-repeat fixed center center"; 
var bg15 = "#000 url('./images/background/image_15.jpg') no-repeat fixed center center"; 

var bg16 = "#000 url('./images/background/image_16.jpg') no-repeat fixed center center"; 
var bg17 = "#000 url('./images/background/image_17.jpg') no-repeat fixed center center"; 
var bg18 = "#000 url('./images/background/image_18.jpg') no-repeat fixed center center"; 

var bg19 = "#000 url('./images/background/image_19.jpg') no-repeat fixed center center"; 
var bg20 = "#000 url('./images/background/image_20.jpg') no-repeat fixed center center"; 
var bg21 = "#000 url('./images/background/image_21.jpg') no-repeat fixed center center"; 

var bg22 = "#000 url('./images/background/image_22.jpg') no-repeat fixed center center"; 
var bg23 = "#000 url('./images/background/image_23.jpg') no-repeat fixed center center"; 
var bg24 = "#000 url('./images/background/image_24.jpg') no-repeat fixed center center"; 

var bg25 = "#000 url('./images/background/image_25.jpg') no-repeat fixed center center"; 
var bg26 = "#000 url('./images/background/image_26.jpg') no-repeat fixed center center"; 
var bg27 = "#000 url('./images/background/image_27.jpg') no-repeat fixed center center"; 

var bg28 = "#000 url('./images/background/image_28.jpg') no-repeat fixed center center"; 
var bg29 = "#000 url('./images/background/image_29.jpg') no-repeat fixed center center"; 
var bg30 = "#000 url('./images/background/image_30.jpg') no-repeat fixed center center"; 

var bg31 = "#000 url('./images/background/image_31.jpg') no-repeat fixed center center"; 
var bg32 = "#000 url('./images/background/image_32.jpg') no-repeat fixed center center"; 
var bg33 = "#000 url('./images/background/image_33.jpg') no-repeat fixed center center"; 

var bg34 = "#000 url('./images/background/image_34.jpg') no-repeat fixed center center"; 
var bg35 = "#000 url('./images/background/image_35.jpg') no-repeat fixed center center"; 
var bg36 = "#000 url('./images/background/image_36.jpg') no-repeat fixed center center"; 

var bg37 = "#000 url('./images/background/image_37.jpg') no-repeat fixed center center"; 
var bg38 = "#000 url('./images/background/image_38.jpg') no-repeat fixed center center"; 
var bg39 = "#000 url('./images/background/image_39.jpg') no-repeat fixed center center"; 

var bg40 = "#000 url('./images/background/image_40.jpg') no-repeat fixed center center"; 
var bg41 = "#000 url('./images/background/image_41.jpg') no-repeat fixed center center"; 

var images = [bg30, bg34, bg6, bg7, bg10, bg36, bg33, bg26, bg14, bg5, bg40, bg13, bg16, bg23, bg8, bg18, bg32, bg14, bg31, bg15, bg24, bg20, bg22, bg29, bg37, bg41, bg27, bg25, bg12, bg9, bg4, bg21, bg19, bg1, bg28, bg3, bg2, bg39, bg38]; 

var current = 0; 

for (var a = 0; a < 39; a++) 
{ 
$('#fade1').fadeOut(16000, function() 
{ 
    $('#fade1').css("background", images[current]); 
    current++; 
}); 

if (current > 38) 
{ 
    current = 0; 
} 

$('#fade1').fadeIn(16000, function() 
{ 
    $('#background').css("background", images[current]); 
    current++; 
}); 

if (current > 38) 
{ 
    current = 0; 
} 

$('#fade1').fadeOut(16000, function() 
{ 
    $('#fade1').css("background", images[current]); 
    current++; 
}); 

if (current > 38) 
{ 
    current = 0; 
} 
} 

主要代码第2部分：

var backgroundFader = function(element, bgClasses, nextChange) 

{ 
this.cssProps = {'position' : 'relative', 'z-index' : 100}; 
this.bgs = ['bg1', 'bg2', 'bg3', 'bg4', 'bg5', 'bg6', 'bg7', 'bg8', 'bg9', 'bg10', 'bg11', 'bg12', 'bg13', 'bg14', 'bg15', 'bg16', 'bg17', 'bg18', 'bg19', 'bg20', 'bg21', 'bg22', 'bg23', 'bg24', 'bg25', 'bg26', 'bg27', 'bg28', 'bg29', 'bg30', 'bg31', 'bg32', 'bg33', 'bg34', 'bg35', 'bg36', 'bg37', 'bg38', 'bg39', 'bg40', 'bg41']; 

this.element = element || ".bg_fader"; 
}; 

function insertLayer(element) 
{ 
var cssProps = {'position' : 'relative', 'z-index' : 100}; 
var bgs = ['bg1', 'bg2', 'bg3', 'bg4', 'bg5', 'bg6', 'bg7', 'bg8', 'bg9', 'bg10', 'bg11', 'bg12', 'bg13', 'bg14', 'bg15', 'bg16', 'bg17', 'bg18', 'bg19', 'bg20', 'bg21', 'bg22', 'bg23', 'bg24', 'bg25', 'bg26', 'bg27', 'bg28', 'bg29', 'bg30', 'bg31', 'bg32', 'bg33', 'bg34', 'bg35', 'bg36', 'bg37', 'bg38', 'bg39', 'bg40', 'bg41']; 

var element = element || ".bg_fader"; 

var layerel = element.substr(1) + "-layer"; 
if(jQuery("#"+layerel).length == 0) 
{ 
    jQuery("<div id='"+layerel+"'></div>") 
    .insertAfter(element) 
    .nextAll().appendTo("#"+layerel) 
    .parent().css(cssProps); 
} 
} 

感谢您的帮助！

Answer 1

必须在这方面与mkoryak一起。代码过度复杂化了这个问题。

这是我会怎么做（这当然是完全未经测试）：

var fade_time = 1000; 
var wait_time = 15000; 
var curr = 0; 
var last = 41; 
var bg = $("#background"); 

function do_fade() { 
    curr++; 
    if (curr > last) { 
     curr = 1; 
    } 
    bg.fadeOut(fade_time, function() { 
     // switch your image here. something like this 
     bg.css('background-image','./images/background/image_' + curr + '.jpg'); 
     bg.fadeIn(fade_time); 
    } 
} 

id = setInterval(do_fade, wait_time); 

希望这对你的作品。

Answer 2

首先，您可以将该代码重写为小约7倍。使用循环和东西。

在你的问题：

我怀疑它是与你有一个无限循环，也就是说，套一堆淡出一些东西定时器的。因为你经常循环并创建越来越多的定时器，你将会得到不可预知的结果，比如一些图像没有被使用。

我怀疑你不知道fadeOut和fadeIn是如何工作的。那些电话队列动画，他们不会阻止执行！所以实际上你总是在排队等待一大堆东西，一直在。

此外，你应该考虑使用萤火虫调试

Answer 3

你可能想寻找到一个jQuery插件来获得这种效果;那里有很多“幻灯片”风格的插件。例如，请参阅Cycle。

Answer 4

只是想我会提到这个片段。背景图像应该和普通图像一样。如果你有很多图片，我不会在页面加载时预加载所有图片，而是使用一些队列系统。

<script type="text/javascript"> 
     <? 
     $i = 0; 
     if ($handle = opendir('./images/background')) { 
      while (false !== ($file = readdir($handle))) { 
       if ($file != "." && $file != "..") { 
        echo "preloadimage_".$i." = new Image();\n\t"; 
        echo "preloadimage_".$i++.".src = \"/images/background/".$file."\";\n\t"; 
       } 
      } 
      closedir($handle); 
     } 
     ?> 
    </script>