滑动滚轮放大缩小

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    *</span><span style="background-color: #f5f5f5; color: #000000;">{</span><span style="background-color: #f5f5f5; color: #ff0000;">margin</span><span style="background-color: #f5f5f5; color: #000000;">:</span><span style="background-color: #f5f5f5; color: #0000ff;">0</span><span style="background-color: #f5f5f5; color: #000000;">;</span><span style="background-color: #f5f5f5; color: #ff0000;"> padding</span><span style="background-color: #f5f5f5; color: #000000;">:</span><span style="background-color: #f5f5f5; color: #0000ff;">0</span><span style="background-color: #f5f5f5; color: #000000;">;</span><span style="background-color: #f5f5f5; color: #ff0000;"> list-style</span><span style="background-color: #f5f5f5; color: #000000;">:</span><span style="background-color: #f5f5f5; color: #0000ff;">none</span><span style="background-color: #f5f5f5; color: #000000;">;</span><span style="background-color: #f5f5f5; color: #000000;">}</span><span style="background-color: #f5f5f5; color: #800000;">
    body</span><span style="background-color: #f5f5f5; color: #000000;">{</span><span style="background-color: #f5f5f5; color: #ff0000;">
        height</span><span style="background-color: #f5f5f5; color: #000000;">:</span><span style="background-color: #f5f5f5; color: #0000ff;"> 2000px</span><span style="background-color: #f5f5f5; color: #000000;">;</span>
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    #box</span><span style="background-color: #f5f5f5; color: #000000;">{</span><span style="background-color: #f5f5f5; color: #ff0000;">
        width</span><span style="background-color: #f5f5f5; color: #000000;">:</span><span style="background-color: #f5f5f5; color: #0000ff;"> 200px</span><span style="background-color: #f5f5f5; color: #000000;">;</span><span style="background-color: #f5f5f5; color: #ff0000;">
        height</span><span style="background-color: #f5f5f5; color: #000000;">:</span><span style="background-color: #f5f5f5; color: #0000ff;"> 200px</span><span style="background-color: #f5f5f5; color: #000000;">;</span><span style="background-color: #f5f5f5; color: #ff0000;">
        background</span><span style="background-color: #f5f5f5; color: #000000;">:</span><span style="background-color: #f5f5f5; color: #0000ff;"> green</span><span style="background-color: #f5f5f5; color: #000000;">;</span>
    <span style="background-color: #f5f5f5; color: #000000;">}</span>
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<span style="color: #0000ff;"><span style="color: #800000;">div </span><span style="color: #ff0000;">id</span><span style="color: #0000ff;">="box"</span><span style="color: #0000ff;">></span><span style="color: #800000;">div</span><span style="color: #0000ff;">></span>
<span style="color: #0000ff;"><span style="color: #800000;">script</span><span style="color: #0000ff;">></span>
    <span style="background-color: #f5f5f5; color: #0000ff;">var</span><span style="background-color: #f5f5f5; color: #000000;"> box</span><span style="background-color: #f5f5f5; color: #000000;">=</span><span style="background-color: #f5f5f5; color: #000000;">document.getElementById(</span><span style="background-color: #f5f5f5; color: #000000;">'</span><span style="background-color: #f5f5f5; color: #000000;">box</span><span style="background-color: #f5f5f5; color: #000000;">'</span><span style="background-color: #f5f5f5; color: #000000;">);
    </span><span style="background-color: #f5f5f5; color: #0000ff;">var</span><span style="background-color: #f5f5f5; color: #000000;"> str</span><span style="background-color: #f5f5f5; color: #000000;">=</span><span style="background-color: #f5f5f5; color: #000000;">window.navigator.userAgent.toLowerCase();
    </span><span style="background-color: #f5f5f5; color: #0000ff;">if</span><span style="background-color: #f5f5f5; color: #000000;"> (str.indexOf(</span><span style="background-color: #f5f5f5; color: #000000;">'</span><span style="background-color: #f5f5f5; color: #000000;">firefox</span><span style="background-color: #f5f5f5; color: #000000;">'</span><span style="background-color: #f5f5f5; color: #000000;">)</span><span style="background-color: #f5f5f5; color: #000000;">!=-</span><span style="background-color: #f5f5f5; color: #000000;">1</span><span style="background-color: #f5f5f5; color: #000000;">) {</span><span style="background-color: #f5f5f5; color: #008000;">//</span><span style="background-color: #f5f5f5; color: #008000;">火狐浏览器</span>
<span style="background-color: #f5f5f5; color: #000000;">        box.addEventListener(</span><span style="background-color: #f5f5f5; color: #000000;">'</span><span style="background-color: #f5f5f5; color: #000000;">DOMMouseScroll</span><span style="background-color: #f5f5f5; color: #000000;">'</span><span style="background-color: #f5f5f5; color: #000000;">,</span><span style="background-color: #f5f5f5; color: #0000ff;">function</span><span style="background-color: #f5f5f5; color: #000000;"> (event){
            </span><span style="background-color: #f5f5f5; color: #008000;">//</span><span style="background-color: #f5f5f5; color: #008000;"> event.preventDefault();//阻止窗口默认的滚动事件</span>
        <span style="background-color: #f5f5f5; color: #008000;">//</span><span style="background-color: #f5f5f5; color: #008000;"> console.log(event.detail);//前滚-3</span>
        <span style="background-color: #f5f5f5; color: #0000ff;">if</span><span style="background-color: #f5f5f5; color: #000000;"> (event.detail</span><span style="background-color: #f5f5f5; color: #000000;"><span style="background-color: #f5f5f5; color: #000000;">0</span><span style="background-color: #f5f5f5; color: #000000;">) {
            console.log(</span><span style="background-color: #f5f5f5; color: #000000;">'</span><span style="background-color: #f5f5f5; color: #000000;">前滚</span><span style="background-color: #f5f5f5; color: #000000;">'</span><span style="background-color: #f5f5f5; color: #000000;">);
            box.style.width</span><span style="background-color: #f5f5f5; color: #000000;">=</span><span style="background-color: #f5f5f5; color: #000000;">box.offsetWidth</span><span style="background-color: #f5f5f5; color: #000000;">+</span><span style="background-color: #f5f5f5; color: #000000;">20</span><span style="background-color: #f5f5f5; color: #000000;">+</span><span style="background-color: #f5f5f5; color: #000000;">'</span><span style="background-color: #f5f5f5; color: #000000;">px</span><span style="background-color: #f5f5f5; color: #000000;">'</span><span style="background-color: #f5f5f5; color: #000000;">;
            box.style.height</span><span style="background-color: #f5f5f5; color: #000000;">=</span><span style="background-color: #f5f5f5; color: #000000;">box.offsetHeight</span><span style="background-color: #f5f5f5; color: #000000;">+</span><span style="background-color: #f5f5f5; color: #000000;">20</span><span style="background-color: #f5f5f5; color: #000000;">+</span><span style="background-color: #f5f5f5; color: #000000;">'</span><span style="background-color: #f5f5f5; color: #000000;">px</span><span style="background-color: #f5f5f5; color: #000000;">'</span><span style="background-color: #f5f5f5; color: #000000;">;
        };
        </span><span style="background-color: #f5f5f5; color: #0000ff;">if</span><span style="background-color: #f5f5f5; color: #000000;"> (event.detail</span><span style="background-color: #f5f5f5; color: #000000;">></span><span style="background-color: #f5f5f5; color: #000000;">0</span><span style="background-color: #f5f5f5; color: #000000;">) {
            console.log(</span><span style="background-color: #f5f5f5; color: #000000;">'</span><span style="background-color: #f5f5f5; color: #000000;">后滚</span><span style="background-color: #f5f5f5; color: #000000;">'</span><span style="background-color: #f5f5f5; color: #000000;">);
            box.style.width</span><span style="background-color: #f5f5f5; color: #000000;">=</span><span style="background-color: #f5f5f5; color: #000000;">box.offsetWidth</span><span style="background-color: #f5f5f5; color: #000000;">-</span><span style="background-color: #f5f5f5; color: #000000;">20</span><span style="background-color: #f5f5f5; color: #000000;">+</span><span style="background-color: #f5f5f5; color: #000000;">'</span><span style="background-color: #f5f5f5; color: #000000;">px</span><span style="background-color: #f5f5f5; color: #000000;">'</span><span style="background-color: #f5f5f5; color: #000000;">;
            box.style.height</span><span style="background-color: #f5f5f5; color: #000000;">=</span><span style="background-color: #f5f5f5; color: #000000;">box.offsetHeight</span><span style="background-color: #f5f5f5; color: #000000;">-</span><span style="background-color: #f5f5f5; color: #000000;">20</span><span style="background-color: #f5f5f5; color: #000000;">+</span><span style="background-color: #f5f5f5; color: #000000;">'</span><span style="background-color: #f5f5f5; color: #000000;">px</span><span style="background-color: #f5f5f5; color: #000000;">'</span><span style="background-color: #f5f5f5; color: #000000;">;
        };
        </span><span style="background-color: #f5f5f5; color: #0000ff;">return</span> <span style="background-color: #f5f5f5; color: #0000ff;">false</span><span style="background-color: #f5f5f5; color: #000000;">;</span><span style="background-color: #f5f5f5; color: #008000;">//</span><span style="background-color: #f5f5f5; color: #008000;">阻止默认事件</span>
<span style="background-color: #f5f5f5; color: #000000;">        },</span><span style="background-color: #f5f5f5; color: #0000ff;">false</span><span style="background-color: #f5f5f5; color: #000000;">);
    } </span><span style="background-color: #f5f5f5; color: #0000ff;">else</span><span style="background-color: #f5f5f5; color: #000000;">{</span><span style="background-color: #f5f5f5; color: #008000;">//</span><span style="background-color: #f5f5f5; color: #008000;">非火狐浏览器</span>
<span style="background-color: #f5f5f5; color: #000000;">        box.onmousewheel</span><span style="background-color: #f5f5f5; color: #000000;">=</span><span style="background-color: #f5f5f5; color: #0000ff;">function</span><span style="background-color: #f5f5f5; color: #000000;"> (ev){
            </span><span style="background-color: #f5f5f5; color: #0000ff;">var</span><span style="background-color: #f5f5f5; color: #000000;"> e</span><span style="background-color: #f5f5f5; color: #000000;">=</span><span style="background-color: #f5f5f5; color: #000000;">ev</span><span style="background-color: #f5f5f5; color: #000000;">||</span><span style="background-color: #f5f5f5; color: #000000;">window.event;
            </span><span style="background-color: #f5f5f5; color: #008000;">/*</span><span style="background-color: #f5f5f5; color: #008000;">if (e.preventDefault) {
                e.preventDefault();
            } else{
                e.returnValue=false;
            };</span><span style="background-color: #f5f5f5; color: #008000;">*/</span>
            <span style="background-color: #f5f5f5; color: #008000;">//</span><span style="background-color: #f5f5f5; color: #008000;"> console.log(e);</span>
            <span style="background-color: #f5f5f5; color: #008000;">//</span><span style="background-color: #f5f5f5; color: #008000;"> console.log(e.wheelDelta);//前滚120</span>
            <span style="background-color: #f5f5f5; color: #0000ff;">if</span><span style="background-color: #f5f5f5; color: #000000;"> (e.wheelDelta</span><span style="background-color: #f5f5f5; color: #000000;">></span><span style="background-color: #f5f5f5; color: #000000;">0</span><span style="background-color: #f5f5f5; color: #000000;">) {
            console.log(</span><span style="background-color: #f5f5f5; color: #000000;">'</span><span style="background-color: #f5f5f5; color: #000000;">前滚</span><span style="background-color: #f5f5f5; color: #000000;">'</span><span style="background-color: #f5f5f5; color: #000000;">);
            box.style.width</span><span style="background-color: #f5f5f5; color: #000000;">=</span><span style="background-color: #f5f5f5; color: #000000;">box.offsetWidth</span><span style="background-color: #f5f5f5; color: #000000;">+</span><span style="background-color: #f5f5f5; color: #000000;">20</span><span style="background-color: #f5f5f5; color: #000000;">+</span><span style="background-color: #f5f5f5; color: #000000;">'</span><span style="background-color: #f5f5f5; color: #000000;">px</span><span style="background-color: #f5f5f5; color: #000000;">'</span><span style="background-color: #f5f5f5; color: #000000;">;
            box.style.height</span><span style="background-color: #f5f5f5; color: #000000;">=</span><span style="background-color: #f5f5f5; color: #000000;">box.offsetHeight</span><span style="background-color: #f5f5f5; color: #000000;">+</span><span style="background-color: #f5f5f5; color: #000000;">20</span><span style="background-color: #f5f5f5; color: #000000;">+</span><span style="background-color: #f5f5f5; color: #000000;">'</span><span style="background-color: #f5f5f5; color: #000000;">px</span><span style="background-color: #f5f5f5; color: #000000;">'</span><span style="background-color: #f5f5f5; color: #000000;">;
        };
        </span><span style="background-color: #f5f5f5; color: #0000ff;">if</span><span style="background-color: #f5f5f5; color: #000000;"> (e.wheelDelta</span><span style="background-color: #f5f5f5; color: #000000;"><span style="background-color: #f5f5f5; color: #000000;">0</span><span style="background-color: #f5f5f5; color: #000000;">) {
            console.log(</span><span style="background-color: #f5f5f5; color: #000000;">'</span><span style="background-color: #f5f5f5; color: #000000;">后滚</span><span style="background-color: #f5f5f5; color: #000000;">'</span><span style="background-color: #f5f5f5; color: #000000;">);
            box.style.width</span><span style="background-color: #f5f5f5; color: #000000;">=</span><span style="background-color: #f5f5f5; color: #000000;">box.offsetWidth</span><span style="background-color: #f5f5f5; color: #000000;">-</span><span style="background-color: #f5f5f5; color: #000000;">20</span><span style="background-color: #f5f5f5; color: #000000;">+</span><span style="background-color: #f5f5f5; color: #000000;">'</span><span style="background-color: #f5f5f5; color: #000000;">px</span><span style="background-color: #f5f5f5; color: #000000;">'</span><span style="background-color: #f5f5f5; color: #000000;">;
            box.style.height</span><span style="background-color: #f5f5f5; color: #000000;">=</span><span style="background-color: #f5f5f5; color: #000000;">box.offsetHeight</span><span style="background-color: #f5f5f5; color: #000000;">-</span><span style="background-color: #f5f5f5; color: #000000;">20</span><span style="background-color: #f5f5f5; color: #000000;">+</span><span style="background-color: #f5f5f5; color: #000000;">'</span><span style="background-color: #f5f5f5; color: #000000;">px</span><span style="background-color: #f5f5f5; color: #000000;">'</span><span style="background-color: #f5f5f5; color: #000000;">;
        };
        </span><span style="background-color: #f5f5f5; color: #0000ff;">return</span> <span style="background-color: #f5f5f5; color: #0000ff;">false</span><span style="background-color: #f5f5f5; color: #000000;">;</span><span style="background-color: #f5f5f5; color: #008000;">//</span><span style="background-color: #f5f5f5; color: #008000;">阻止默认事件</span>
<span style="background-color: #f5f5f5; color: #000000;">        }
    };
    
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