JavaScript_js放大镜放大图片效果，phpStudy js图片放大镜 body

js放大镜放大图片效果

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd"> 
<html><head><title>phpStudy js图片放大镜</title> 
<meta http-equiv="imagetoolbar" content="no"> 
<style type="text/css"> 
    body { 
        background: #222; 
        overflow: hidden; 
        left: 0; 
        top: 0; 
        width: 100%; 
        height: 100%; 
        margin: 0; 
        padding: 0; 
    } 
    #screen span { 
        position:absolute; 
        overflow:hidden; 
        border:#FFF solid 1px; 
        background:#FFF; 
    } 
    #screen img{ 
        position:absolute; 
        left:-32px; 
        top:-32px; 
        cursor: pointer; 
    } 
    #caption, #title{ 
        color: #FFF; 
        font-family: georgia, 'times new roman', times, veronica, serif; 
        font-size: 1em; 
        text-align: center; 
    } 
    #caption b { 
        font-size: 2em; 
    }

</style>

/* needed in standard mode */ 
px = function(x) 
{ 
    return Math.round(x) + "px"; 
}

/* center image  - do not resize for perf. reason */ 
img_center = function(o) 
{ 
    with(img[o]) 
    { 
        style.left = px( - (width - Wi) / 2); 
        style.top = px( - (height - Hi) / 2); 
    } 
}

////////////////////////////////////////////////////////// 
var Nx = 4; //size grid x 
var Ny = 4; //size grid y 
var Tx = 3; // image width 
var Ty = 3; // image height 
var Mg = 40; // margin 
var SP = 1; // speed 
//////////////////////////////////////////////////////////

function Cobj(o, x, y) 
{ 
    this.o = o; 
    this.ix = Math.min(Nx - Tx, Math.max(0, Math.round(x - (Tx / 2)))); 
    this.iy = Math.min(Ny - Ty, Math.max(0, Math.round(y - (Ty / 2)))); 
    this.li = ((this.ix * M + this.ix * Sx) - (x * M + x * Sx)) / SP; 
    this.ti = ((this.iy * M + this.iy * Sy) - (y * M + y * Sy)) / SP; 
    this.l = 0; 
    this.t = 0; 
    this.w = 0; 
    this.h = 0; 
    this.s = 0; 
    this.mv = false; 
    this.spa = spa[o].style; 
    this.img = img[o]; 
    this.txt = img[o].alt; 
    img[o].alt = "";

/* zooming loop */ 
    this.zoom = function() 
    { 
        with(this) 
        { 
            l += li * s; 
            t += ti * s; 
            w += wi * s; 
            h += hi * s; 
            if ((s > 0 && w < Wi) || (s < 0 && w > Sx)) 
            { 
                /* force window.event */ 
                window.focus(); 
                /* loop */ 
                setTimeout("obj[" + o + "].zoom()", 16); 
            } 
            else 
            { 
                /* finished */ 
                mv = false; 
                /* set final position */ 
                if (s > 0) 
                { 
                    l = ix * M + ix * Sx; 
                    t = iy * M + iy * Sy; 
                    w = Wi; 
                    h = Hi; 
                } 
                else 
                { 
                    l = x * M + x * Sx; 
                    t = y * M + y * Sy; 
                    w = Sx; 
                    h = Sy; 
                } 
            } 
            /* html animation */ 
            with(spa) 
            { 
                left = px(l); 
                top = px(t); 
                width = px(w); 
                height = px(h); 
                zIndex = Math.round(w); 
            } 
        } 
    }

this.click = function() 
    { 
        with(this) 
        { 
            img_center(o); 
            /* zooming logic */ 
            if ( ! mv || cl) 
            { 
                if (s > 0) 
                { 
                    if (cl || Math.abs(xm - xb) > Sx * .4 || Math.abs(ym - yb) > Sy * .4) 
                    { 
                        s =  - 2; 
                        mv = true; 
                        zoom(); 
                        cap.innerHTML = txt; 
                    } 
                } 
                else 
                { 
                    if (cl || ob != o) 
                    { 
                        if (ob >= 0) 
                        { 
                            with(obj[ob]) 
                            { 
                                s =  - 2; 
                                mv = true; 
                                zoom(); 
                            } 
                        } 
                        ob = o; 
                        s = 1; 
                        xb = xm; 
                        yb = ym; 
                        mv = true; 
                        zoom(); 
                        cap.innerHTML = txt; 
                    } 
                } 
            } 
        } 
    } 
     
    /* hook up events */ 
    img[o].onmouseover = img[o].onmousemove = img[o].onmouseout = new Function("cl=false;obj[" + o + "].click()"); 
    img[o].onclick = new Function("cl=true;obj[" + o + "].click()"); 
    img[o].onload = new Function("img_center(" + o + ")");

/* initial display */ 
    this.zoom(); 
}

/* mouse */ 
document.onmousemove = function(e) 
{ 
    if ( ! e) 
    { 
        e = window.event; 
    } 
    xm = (e.x || e.clientX); 
    ym = (e.y || e.clientY); 
}

/* init */ 
function load() 
{ 
    /* html elements */ 
    scr = document.getElementById("screen"); 
    spa = scr.getElementsByTagName("span"); 
    img = scr.getElementsByTagName("img"); 
    cap = document.getElementById("caption"); 
     
    /* mouseover border */  
    document.getElementById("border").onmouseover = function() 
    { 
        cl = true; 
        if(ob >= 0 && obj[ob].s > 0) obj[ob].click(); 
        ob = -1; 
    }

/* global variables */ 
    W = parseInt(scr.style.width); 
    H = parseInt(scr.style.height); 
    M = W / Mg; 
    Sx = (W - (Nx - 1) * M) / Nx; 
    Sy = (H - (Ny - 1) * M) / Ny; 
    Wi = Tx * Sx + (Tx - 1) * M; 
    Hi = Ty * Sy + (Ty - 1) * M; 
    SP = M * Tx * SP; 
    wi = (Wi - Sx) / SP; 
    hi = (Hi - Sy) / SP; 
     
    /* create objects */ 
    for (k = 0, i = 0; i < Nx; i ++) 
    { 
        for (j = 0; j < Ny; j ++) 
        { 
            obj[k] = new Cobj(k ++, i, j); 
        } 
    } 
} 
//--> 
</script></head><body>

<div style="position: absolute; left: 50%; top: 50%;"> 
    <div id="title" style="position: absolute; width: 440px; height: 40px; left: -220px; top: -200px;"></div> 
    <div id="border" style="border: 1px solid rgb(85, 85, 85); background: rgb(0, 0, 0) none repeat scroll 0%; position: absolute; width: 440px; height: 340px; left: -220px; top: -170px; -moz-background-clip: -moz-initial; -moz-background-origin: -moz-initial; -moz-background-inline-policy: -moz-initial;"></div> 
    <div id="screen" style="background: rgb(0, 0, 0) none repeat scroll 0%; position: absolute; width: 400px; height: 300px; left: -200px; top: -150px; -moz-background-clip: -moz-initial; -moz-background-origin: -moz-initial; -moz-background-inline-policy: -moz-initial;"> 
        <span style="left: 0px; top: 0px; width: 93px; height: 68px; z-index: 93;"></span> 
        <span style="left: 0px; top: 78px; width: 93px; height: 68px; z-index: 93;"></span> 
        <span style="left: 0px; top: 155px; width: 93px; height: 68px; z-index: 93;"></span> 
        <span style="left: 0px; top: 233px; width: 93px; height: 68px; z-index: 93;"></span> 
        <span style="left: 103px; top: 0px; width: 93px; height: 68px; z-index: 93;"></span> 
        <span style="left: 103px; top: 78px; width: 93px; height: 68px; z-index: 93;"></span> 
        <span style="left: 103px; top: 155px; width: 93px; height: 68px; z-index: 93;"></span> 
        <span style="left: 103px; top: 233px; width: 93px; height: 68px; z-index: 93;"></span> 
        <span style="left: 205px; top: 0px; width: 93px; height: 68px; z-index: 93;"></span> 
        <span style="left: 205px; top: 78px; width: 93px; height: 68px; z-index: 93;"></span> 
        <span style="left: 205px; top: 155px; width: 93px; height: 68px; z-index: 93;"></span> 
        <span style="left: 205px; top: 233px; width: 93px; height: 68px; z-index: 93;"></span> 
        <span style="left: 308px; top: 0px; width: 93px; height: 68px; z-index: 93;"></span> 
        <span style="left: 308px; top: 78px; width: 93px; height: 68px; z-index: 93;"></span> 
        <span style="left: 308px; top: 155px; width: 93px; height: 68px; z-index: 93;"></span> 
        <span style="left: 308px; top: 233px; width: 93px; height: 68px; z-index: 93;"></span> 
    </div> 
    <div id="caption" style="position: absolute; width: 440px; height: 60px; left: -220px; top: 175px;"><b>carefully</b> weight the options</div> 
</div>

</body></html>

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