JavaScript 图片上传预览效果(14)

该文档说了怎么在页面做图片预览, 一步一步的

}

},

//预览程序

_preview: function(data) {

//空值或相同的值不执行显示

if ( !!data && data !== this._data ) {

this._data = data; this._show();

}

},

//设置一般预载图片对象

_simplePreload: function() {

if ( !this._preload ) {

var preload = this._preload = new Image(), oThis = this,

onload = function(){ oThis._imgShow( oThis._data, this.width, this.height ); }; this._onload = function(){ this.onload = null; onload.call(this); }

preload.onload = $$B.ie ? this._onload : onload;

preload.onerror = function(){ oThis._error(); };

} else if ( $$B.ie ) {

this._preload.onload = this._onload;

}

},

//一般显示

_simpleShow: function() {

this._simplePreload();

this._preload.src = this._data;

},

//设置滤镜预载图片对象

_filterPreload: function() {

if ( !this._preload ) {

var preload = this._preload = document.createElement("div");

//隐藏并设置滤镜

$$D.setStyle( preload, {

width: "1px", height: "1px",

visibility: "hidden", position: "absolute", left: "-9999px", top: "-9999px", filter:

"progid:DXImageTransform.Microsoft.AlphaImageLoader(sizingMethod='image')"

});

//插入body

var body = document.body; body.insertBefore( preload, body.childNodes[0] ); }

},