JavaScript picture switching display effect alibaba extended version_Image special effects JavaScript picture switching display effect

I saw a picture switching effect from Alibaba, which I thought was good and I wanted to use it. But there is a lot of code, and it looks dizzy, so I’d better do it myself. Since I have experience in making picture sliding display effects, it is much easier to do this.

First you need a container, set its overflow to hidden and position to relative;
There is also a sliding object in the container, set its position to absolute;
Initialize in the initialize() function some properties.

Execute the Start() function before switching and make relevant settings.
Mainly set the Index attribute (index) and _target attribute (target value):

if(this.Index < 0){ 
this.Index = this._count - 1; 
} else if (this.Index >= this._count){ this.Index = 0; } 
this._target = -1 * this._parameter * this.Index;

Then Just execute the Move() function to start moving. The principle is to create the moving effect by setting the top (or left) of the sliding object.
The deceleration effect requires executing the GetStep() function to obtain the step size:

var iStep = (iTarget - iNow) / this.Step;用目标值减当前值再除以一个参数，得到步长，

The step size obtained in this way will become smaller and smaller as the current value is closer to the target value, which also creates a deceleration effect.
Then add this step in the settings of top (or left) long, and set the timer to continue Move() until the target value is reached:

this._slider.style[style] = (iNow + iStep) + "px"; 
this._timer = setTimeout(function(){ oThis.Move(); }, this.Time);

Container structure in the following example:

<p class="container" id="idTransformView"> 
<ul class="slider" id="idSlider"> 
<li><img src="http://shundebk.cn/temp/1.jpg"/></li> 
<li><img src="http://shundebk.cn/temp/2.jpg"/></li> 
<li><img src="http://shundebk.cn/temp/3.gif"/></li> 
</ul> 
<ul class="num" id="idNum"> 
<li>1</li> 
<li>2</li> 
<li>3</li> 
</ul> 
</p>

If you want it to be beautiful, you need to set it with css:

.container, .container *{margin:0; padding:0;} 
.container{width:408px; height:168px; overflow:hidden;} 
.slider{position:absolute;} 
.slider li{ list-style:none;display:inline;} 
.slider img{ width:408px; height:168px; display:block;} 
.slider2{width:2000px;} 
.slider2 li{float:left;} 
.num{ position:absolute; right:5px; bottom:5px;} 
.num li{ 
float: left; 
color: #FF7300; 
text-align: center; 
line-height: 16px; 
width: 16px; 
height: 16px; 
font-family: Arial; 
font-size: 12px; 
cursor: pointer; 
overflow: hidden; 
margin: 3px 1px; 
border: 1px solid #FF7300; 
background-color: #fff; 
} 
.num li.on{ 
color: #fff; 
line-height: 21px; 
width: 21px; 
height: 21px; 
font-size: 16px; 
margin: 0 1px; 
border: 0; 
background-color: #FF7300; 
font-weight: bold; 
}

The setting of style is also related to the program, such as width and height, which will not be explained here.
Then you can instantiate:

var tv = new TransformView ("idTransformView", "idSlider", 168, 3, { 
onStart : function(){ Each(objs, function(o, i) { o.className = tv.Index == i ? "on" : ""; }) }//按钮样式 
});

There are mainly 4 parameters here, namely container object, sliding object, switching parameter and switching quantity.
When the program switches up and down, it is the height of the switching parameter. When it switches left and right, it is the width of the switching.
The number of switching is how many switching objects there are. For example, the above example is 3.
The last parameters are some settings:
Attribute: Default value//Description
Up: true,//Whether to go up (otherwise to the left)
Step: 5,//Sliding change rate
Time: 10,//Sliding delay
Auto: true,//Whether to automatically convert
Pause: 2000,//Pause time (valid when Auto is true)
onStart: function(){} ,//Execute when the conversion starts
onFinish: function(){}//Execute when the conversion is completed
In the example, the onStart attribute is set, and the function is to set the style of the button when the switch starts
The example is complete Test code:

function Each(list, fun){ 
for (var i = 0, len = list.length; i < len; i++) { fun(list[i], i); } 
}; 
var objs = $("idNum").getElementsByTagName("li"); 
var tv = new TransformView("idTransformView", "idSlider", 168, 3, { 
onStart : function(){ Each(objs, function(o, i) { o.className = tv.Index == i ? "on" : ""; }) }//按钮样式 
}); 
tv.Start(); 
Each(objs, function (o, i){ 
o.onmouseover = function(){ 
o.className = "on"; 
tv.Auto = false; 
tv.Index = i; 
tv.Start(); 
} 
o.onmouseout = function(){ 
o.className = ""; 
tv.Auto = true; 
tv.Start(); 
} 
})

Source code:

var $ = function (id) { 
return "string" == typeof id ? 
document.getElementById(id) : id; 
}; 

var Class = { 
create: 
function() { 
return function() { 
this.initialize.apply(this, arguments); 
} 
} 
} 

Object.extend = function(destination, source) { 
for (var property in source) { 
destination[property] = source[property]; 
} 
return destination; 
} 

var TransformView = Class.create(); 
TransformView.prototype = { 
//容器对象,滑动对象,切换参数,切换数量 
initialize: 
function(container, slider, parameter, count, options) { 
if(parameter <= 
0 || count <= 0) return; 
var oContainer = $(container), oSlider = 
$(slider), oThis = this; 

this.Index = 0;//当前索引 

this._timer = 
null;//定时器 
this._slider = oSlider;//滑动对象 
this._parameter = 
parameter;//切换参数 
this._count = count || 0;//切换数量 
this._target = 0;//目标参数 

this.SetOptions(options); 

this.Up = !!this.options.Up; 
this.Step = Math.abs(this.options.Step); 
this.Time = 
Math.abs(this.options.Time); 
this.Auto = !!this.options.Auto; 
this.Pause 
= Math.abs(this.options.Pause); 
this.onStart = this.options.onStart; 
this.onFinish = this.options.onFinish; 

oContainer.style.overflow = 
"hidden"; 
oContainer.style.position = "relative"; 

oSlider.style.position = "absolute"; 
oSlider.style.top = 
oSlider.style.left = 0; 
}, 
//设置默认属性 
SetOptions: function(options) { 
this.options = {//默认值 
Up: true,//是否向上(否则向左) 
Step: 5,//滑动变化率 
Time: 10,//滑动延时 
Auto: true,//是否自动转换 
Pause: 2000,//停顿时间(Auto为true时有效) 
onStart: function(){},//开始转换时执行 
onFinish: function(){}//完成转换时执行 
}; 
Object.extend(this.options, options || {}); 
}, 
//开始切换设置 
Start: 
function() { 
if(this.Index < 0){ 
this.Index = this._count - 1; 
} 
else if (this.Index >= this._count){ this.Index = 0; } 

this._target = 
-1 * this._parameter * this.Index; 
this.onStart(); 
this.Move(); 
}, 
//移动 
Move: function() { 
clearTimeout(this._timer); 
var oThis = 
this, style = this.Up ? "top" : "left", iNow = 
parseInt(this._slider.style[style]) || 0, iStep = this.GetStep(this._target, 
iNow); 

if (iStep != 0) { 
this._slider.style[style] = (iNow + iStep) 
+ "px"; 
this._timer = setTimeout(function(){ oThis.Move(); }, this.Time); 
} else { 
this._slider.style[style] = this._target + "px"; 
this.onFinish(); 
if (this.Auto) { this._timer = setTimeout(function(){ 
oThis.Index++; oThis.Start(); }, this.Pause); } 
} 
}, 
//获取步长 
GetStep: function(iTarget, iNow) { 
var iStep = (iTarget - iNow) / 
this.Step; 
if (iStep == 0) return 0; 
if (Math.abs(iStep) < 1) return 
(iStep > 0 ? 1 : -1); 
return iStep; 
}, 
//停止 
Stop: 
function(iTarget, iNow) { 
clearTimeout(this._timer); 
this._slider.style[this.Up ? "top" : "left"] = this._target + "px"; 
} 
};