Javascript ~ preload images

當網頁有些互動的動作~~~

可能換張圖之類的

為了避免動作之後才開始讀圖片產生的延遲而預先讀圖片

就是preload~~

這邊的範例是透過javascript

if (document.images)

{

preload_image_object = new Image();

// set image url

image_url = new Array();

image_url[0] = 'img/tvwall_phantom.png';

image_url[1] = 'img/tvwall_phantom2.png';

image_url[2] = 'img/tvwall_phantom3.png';

image_url[3] = 'img/tvwall_phantom4.png';

image_url[4] = 'img/tvwall_phantom5.png';

var i = 0;

for(i=0; i<=5; i++)

preload_image_object.src = image_url[i];

}

reference http://www.techrepublic.com/article/preloading-and-the-javascript-image-object/5214317