可见性:隐藏的技巧

我通常会使用可见性:隐藏技巧

这是我设计的按钮

<div id="uploadbutton" class="btn btn-success btn-block">Upload</div>

这是input type=file按钮。注意可见性:隐藏规则

<input type="file" id="upload" style="visibility:hidden;">

这是JavaScript将它们粘合在一起。它的工作原理

<script>
 $('#uploadbutton').click(function(){
    $('input[type=file]').click();
 });
 </script>

我能想到的唯一方法是在它被渲染后用javascript找到按钮，并分配一个样式给它

你也可以看看这个记录

一个图像上传应用程序的演示，适用于大多数后端良好的动画功能。

// common function render_element(styles, el) { for (const [kk, vv] of Object.entries(styles)) { el.style[kk] = vv; } } function hoverOpacity(el) { el.addEventListener('mouseenter', function() { el.style.opacity = 0.75 }.bind(el)); el.addEventListener('mouseleave', function() { el.style.opacity = 1 }.bind(el)); } // return void event handler on setTimeout function buffer(func, time){ return e=>{ if(func.still)return; // first runtime if(!func.pft){ func(e); func.pft = true; func.still = false; return; } func.still = true; setTimeout(e=>{ func(e); func.still = false; }, time); } } // end of common const imageUploadButton = document.getElementById('image-upload-button'); imageUploadButton.addEventListener('click', e=>{ // pulse animation total time const d1 = document.getElementById('image-form'); let time = 600; if(d1.rendered){ d1.ready(); }else{ d1.ready = function(){ d1.style.display = 'flex'; d1.style.background = '#c5edd0'; this.d2.style.background = '#b4dbbf'; this.d3.style.background = '#95dea9'; this.d4.innerHTML = 'Drag and Drop or Click Above to Upload'; } let dismiss_btn = document.createElement('div'); render_element({ position: 'absolute', height: '30px', width: '30px', top: '0', right: '0', background: '#fff', borderRadius: '30px', cursor: 'pointer', margin: '2px', zIndex: '10', }, dismiss_btn); dismiss_btn.addEventListener('mouseenter', function(){this.style.background = '#fc4f30'}); dismiss_btn.addEventListener('mouseleave', function(){this.style.background = '#fff'}); dismiss_btn.addEventListener('click', ()=>{d1.style.display = 'none'}); d1.appendChild(dismiss_btn); const d3 = d1.querySelector('#image-input'); const d5 = d1.querySelector('#image-submit'); d5.style.visibility = 'hidden'; d1.parentNode.removeChild(d1); document.body.appendChild(d1); d1.removeChild(d3); let [ d2, d4, ] = Array.from({length: 3}, ()=>document.createElement('div')); let width = window.innerWidth; let d_styles = { display: 'flex', justifyContent: 'center', alignItems: 'center', }; render_element({ position: 'fixed', left: ((width - 430) / 2).toString() + 'px', width: '430px', top: '60px', height: '280px', zIndex: '10', }, d1); render_element(d_styles, d1); render_element({ width: '90%', height: '90%', }, d2); render_element(d_styles, d2); render_element({ width: '80%', height: '70%', fontSize: '0', cursor: 'pointer', }, d3); hoverOpacity(d3); render_element(d_styles, d3); d1.appendChild(d2); d2.appendChild(d3); let tt = time / 3; let ht = tt / 2; d1.addEventListener('dragover', buffer(e=>{ d1.style.background = '#ebf9f0'; setTimeout(()=>{ d1.style.background = '#95dea9'; }, ht); setTimeout(()=>{ d2.style.background = '#b6e3c2'; setTimeout(()=>{ d2.style.background = '#c4eed2'; }, ht); }, tt); setTimeout(()=>{ d3.style.background = '#cae3d1'; setTimeout(()=>{ d3.style.background = '#9ce2b4'; }, ht); }, tt); }, time)); d2.style.flexDirection = 'column'; render_element({ fontSize: '16px', textAlign: 'center', fontFamily: 'Verdana', }, d4); d2.appendChild(d4); d3.addEventListener('change', e=>{ // backend // d5.click(); // if backend succeed, run frontend setTimeout(()=>{ d1.style.background = '#dbcea2'; setTimeout(()=>{ d2.style.background = '#dbc169'; setTimeout(()=>{ d3.style.background = '#ebc034'; }, ht); }, tt); }, time); // display backend path here // now only display filename d4.innerHTML = d3.files[0].name; }); d1.d2 = d2; d1.d3 = d3; d1.d4 = d4; d1.ready(); d1.rendered = true; } }); #image-upload-button{ width: 200px; height: 40px; background: lightgrey; display: flex; align-items: center; justify-content: center; cursor: pointer; } #image-form{ display: none; } ::-webkit-file-upload-button { visibility: hidden; } <div id="image-upload-button">Upload Image <form id="image-form" action="post"> <input id="image-input" type="file" /> <button id="image-submit" type="submit"></button> </form> </div>

CSS在这里可以做很多事情…耍点小花招……

<div id='wrapper'>
    <input type='file' id='browse'>
</div>
<style>
    #wrapper {
            width: 93px; /*play with this value */
            height: 28px; /*play with this value */
            background: url('browseBtn.png') 0 0 no-repeat;
            border:none;
            overflow:hidden;
    }

    #browse{
            margin-left:-145px; /*play with this value */
            opacity:0; /* set to .5 or something so you can better position it as an overlay then back to zero again after you're done */
            -ms-filter: "progid:DXImageTransform.Microsoft.Alpha(Opacity=0)";
            filter: progid:DXImageTransform.Microsoft.Alpha(Opacity=0);
    }
</style>

::参考::http://site-o-matic.net/?viewpost=19

修道院

我在这里找到了一个使用jQuery的非常聪明的解决方案，它可以在所有旧浏览器和新浏览器中工作。 它使用实际的文件浏览按钮来处理所有样式和click()问题。 我做了一个简单的javascript版本:小提琴 解决方案非常简单，就像天才一样:让文件输入不可见，然后用一段代码把它放在mousecursor下面。

<div class="inp_field_12" onmousemove="file_ho(event,this,1)"><span>browse</span>
    <input id="file_1" name="file_1" type="file" value="" onchange="file_ch(1)">
</div>
<div id="result_1" class="result"></div>
<script>
    function file_ho(e, o, a) {
        e = window.event || e;
        var x = 0,
        y = 0;
        if (o.offsetParent) {
            do {
            x += o.offsetLeft;
            y += o.offsetTop;
            } while (o = o.offsetParent);
        }
    var x1 = e.clientX || window.event.clientX;
    var y1 = e.clientY || window.event.clientY;
    var le = 100 - (x1 - x);
    var to = 10 - (y1 - y);
    document.getElementById('file_' + a).style.marginRight = le + 'px';
    document.getElementById('file_' + a).style.marginTop = -to + 'px';
    }
</script>
<style>
    .inp_field_12 {
        position:relative;
        overflow:hidden;
        float: left;
        width: 130px;
        height: 30px;
        background: orange;
    }
    .inp_field_12 span {
        position: absolute;
        width: 130px;
        font-family:'Calibri', 'Trebuchet MS', sans-serif;
        font-size:17px;
        line-height:27px;
        text-align:center;
        color:#555;
    }
    .inp_field_12 input[type='file'] {
        cursor:pointer;
        cursor:hand;
        position: absolute;
        top: 0px;
        right: 0px;
        -moz-opacity:0;
        filter:alpha(opacity=0);
        opacity: 0;
        outline: none;
        outline-style:none;
        outline-width:0;
        ie-dummy: expression(this.hideFocus=true);
    }
    .inp_field_12:hover {
        background-position:-140px -35px;
    }
    .inp_field_12:hover span {
        color:#fff;
    }
</style>

这里有一个简单的css解决方案，它创建了一个一致的目标区域，并让你的伪造元素的风格，无论你喜欢。

基本思想是这样的:

有两个“假”元素(一个文本输入/链接)作为你的真实文件输入的兄弟。绝对放置它们，让它们完全在你的目标区域上方。 用div包装你的文件输入。将overflow设置为hidden(这样文件输入就不会溢出来)，并使它恰好是你想要的目标区域的大小。 在文件输入上设置不透明度为0，这样它就被隐藏了，但仍然可以点击。给它一个大的字体大小，这样你就可以点击目标区域的所有部分。

下面是jsfiddle: http://jsfiddle.net/gwwar/nFLKU/

<form>
    <input id="faux" type="text" placeholder="Upload a file from your computer" />
    <a href="#" id="browse">Browse </a>
    <div id="wrapper">
        <input id="input" size="100" type="file" />
    </div>
</form>