最近自己没事的时候研究了下图片上传，发现之前写的是有bug的，这里自己重新写了一个！
1、页面结构
<!DOCTYPE html>
<html lang="en"><head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1">
<meta name="renderer" content="webkit">
<link rel="stylesheet" href="jquery.Jcrop.min.css">
<body>
<form method="post" id="uploadimg" name="uploadimg" action="" enctype="multipart/form-data" target="apply_iframe">
<input type="file" id="fileChange" style="color:#000" name="imageFileGuide"/>
</form>
<div class="prew" style="width:300px;height:217px;background:#ccc;position:relative;">
<img src="" id="target" width="100%" style="display:none;position:absolute;top:0;left:0;"/>
<div id="filterPrew" style="display:none;position:absolute;top:0;left:0;"></div>
<img src="" id="filterPrewLoad" style="display:none;" />
</div>
<label>X1坐标</label><input type="text" size="4" id="x1" name="x1" />
<label>Y1坐标</label><input type="text" size="4" id="y1" name="y1" />
<label>X2坐标</label><input type="text" size="4" id="x2" name="x2" />
<label>Y2坐标</label><input type="text" size="4" id="y2" name="y2" />
<label>裁剪的宽</label><input type="text" size="4" id="w" name="w" />
<label>裁剪的高</label><input type="text" size="4" id="h" name="h" />
<label>缩放比例</label><input type="text" size="4" id="R" name="R" value="0"/>
</body>
</html>
<script src="jquery.min.js"></script>
<script src="jquery.Jcrop.min.js"></script>
<script src="upfile.js"></script>
<script>
var dom = $('#fileChange')[0];
var prev = $('.prevw')[0];
szyFile.init(dom,prev,{'Ratio':1.2,'selectWidth':400,'selectHeight':300});
</script>
js逻辑处理
var szyFile = {
fileDom:null,//html 文件上传控件
preview:null,//图片预览的区域
imgMaxSize:2,//图片大小最大2M
filterDom:[],//符合条件的元素
filterImgDataUrl:[],//图片的dataUrl数据
dragArea:null,//拖放区域
jcrop_api:null,
selectWidth:300,//选框宽度
selectHeight:300,//选框高度
Ratio:1,//上传图片比例
imgRegExp:function(f){
if(!/\.(jpg|jpeg|png)$/i.test(f.name)){
alert('您上传的不是图片,请重新选择后上传！');
return false;
}
return true;
},
clearCoords:function(){
$('#coords input').val('');
},
showCoords:function(c){
$('#x1').val(c.x);
$('#y1').val(c.y);
$('#x2').val(c.x2);
$('#y2').val(c.y2);
$('#w').val(c.w);
$('#h').val(c.h);
},
jcropInit:function(ID){
$(ID).Jcrop({
onChange: szyFile.showCoords,
onSelect: szyFile.showCoords,
onRelease: szyFile.clearCoords,
aspectRatio: szyFile.Ratio,
keySupport: false
},function(){
szyFile.jcrop_api = this;
});
$('#coords').on('change','input',function(e){
var x1 = $('#x1').val(),
x2 = $('#x2').val(),
y1 = $('#y1').val(),
y2 = $('#y2').val();
szyFile.jcrop_api.setSelect([x1,y1,x2,y2]);
});
},
isSupport:function(){
if(window.File && window.FileReader && window.FileList && window.Blob) {
return true;
} else {
return false;
}
},
setPrew:function(w,h,ID,modle){
var _top = 0;
var _left = 0;
if(w >= h){
var imgB = szyFile.selectWidth/w;
var imgB1 = w/h;
if(h*imgB <= szyFile.selectHeight){
$(ID).css('width',szyFile.selectWidth+'px');
$(ID).css('height',h*imgB+'px');
_top = ((szyFile.selectHeight-h*imgB)/2);
_left = 0;
$(ID).css('top',_top+'px');
$(ID).css('left',_left+'px');
$('#R').val(w/szyFile.selectWidth);
}else{
$(ID).css('width',szyFile.selectHeight*imgB1+'px');
$(ID).css('height',szyFile.selectHeight+'px');
_top = 0;
_left = ((szyFile.selectWidth-szyFile.selectHeight*imgB1)/2);
$(ID).css('top',_top+'px');
$(ID).css('left',_left+'px');
$('#R').val(h/szyFile.selectHeight);
}
szyFile.jcropInit(ID);
$('.jcrop-holder').css({'position':'absolute','top':_top+'px','left':_left+'px'});
if(modle == 0){
$('.jcrop-tracker').css({'filter':'alpha(opacity=30); BACKGROUND-COLOR: white'});
}
}else{
var imgB = szyFile.selectHeight/h;
var imgB1 = h/w;
if(w*imgB <= szyFile.selectWidth){
$(ID).css('width',w*imgB+'px');
$(ID).css('height',szyFile.selectHeight+'px');
_top = 0;
_left = (szyFile.selectWidth - w*imgB)/2;
$(ID).css('top',_top+'px');
$(ID).css('left',_left+'px');
$('#R').val(h/szyFile.selectHeight);
}else{
$(ID).css('width',szyFile.selectWidth+'px');
$(ID).css('height',szyFile.selectWidth*imgB1+'px');
_top = (szyFile.selectHeight - szyFile.selectWidth*imgB1)/2;
_left = 0;
$(ID).css('top',_top+'px');
$(ID).css('left',_left+'px');
$('#R').val(w/szyFile.selectHeight);
}
szyFile.jcropInit(ID);
$('.jcrop-holder').css({'position':'absolute','top':_top+'px','left':_left+'px'});
if(modle == 0){
$('.jcrop-tracker').css({'filter':'alpha(opacity=30); BACKGROUND-COLOR: white'});
}
}
},
select:function(e){
var e = e || window.event;
if(szyFile.isSupport()){
if(szyFile.jcrop_api){
szyFile.jcrop_api.destroy();
$('#target').remove();
$('<img src="" id="target" width="100%" style="display:none;position:absolute;top:0;left:0;"/>').insertBefore('#filterPrew');
}
$('#target').show();
$('#filterPrew').hide();
var files = e.target.files || e.dataTransfer.files;
for(var i = 0, f; f = files[i]; i++){
if(f){
if(szyFile.imgRegExp(f)){
if(f.size > szyFile.imgMaxSize*1024*1024){
alert('图片过大,您上传的图片大于'+szyFile.imgMaxSize+'MB');
return false;
}else{
szyFile.filterDom.push(f);
var reader = new FileReader();
reader.onload = (function(){
return function(e){
$('#target').attr('src',this.result);
var resultImg = this.result;
var img = new Image();
img.onload = function(){
var w = this.width;
var h = this.height;
szyFile.setPrew(w,h,'#target',1);
}
img.src = this.result;
};
})(f);
reader.readAsDataURL(f);
}
}
}
}
}else{
if(szyFile.jcrop_api){
szyFile.jcrop_api.destroy();
$('<div id="filterPrew" style="display:none;position:absolute;top:0;left:0;"></div>').insertAfter('#target');
}
$('#target').hide();
$('#filterPrew').show();
var src = $('#fileChange')[0].value;
try {
var image = new Image();
image.dynsrc = src;
var filesize = image.fileSize;
} catch (err) {
$('#fileChange')[0].select();
src = document.selection.createRange().text;
}
if(!/\.(jpg|jpeg|png)$/i.test(src)){
alert('您上传的不是图片,请重新选择后上传！');
return false;
}
$('#filterPrew').css('filter','none');
$('#filterPrewLoad').css('filter','none');
$('#filterPrew').css('filter', 'progid:DXImageTransform.Microsoft.AlphaImageLoader(sizingMethod = "scale", src="'+src+'")');
$('#filterPrewLoad').css('filter', 'progid:DXImageTransform.Microsoft.AlphaImageLoader(sizingMethod = "image", src="'+src+'")');
var w = $('#filterPrewLoad').width();
var h = $('#filterPrewLoad').height();
szyFile.setPrew(w,h,'#filterPrew',0);
}
},
fileOnchange:function(elm){
if(elm.addEventListener){
elm.addEventListener('change', this.select, false);
}else{
elm.onchange = function(){
szyFile.select();
}
}
},
fileValue:function(){
return this.fileDom.value;
},
setRadio:function(num){
if(num && num > 0){
szyFile.Ratio = num;
}
},
setSelectWidth:function(num){
if(num && num > 0){
szyFile.selectWidth = num;
}
},
setSelectHeight:function(num){
if(num && num > 0){
szyFile.selectHeight = num;
}
},
setImgMaxSize:function(num){
if(num && num > 0){
szyFile.imgMaxSize = num;
}
},
init:function(dom,prev,config){
if(config.imgMaxSize && config.imgMaxSize > 0){
szyFile.imgMaxSize = config.imgMaxSize;
}
if(config.selectWidth && config.selectWidth > 0){
szyFile.selectWidth = config.selectWidth;
}
if(config.selectHeight && config.selectHeight > 0){
szyFile.selectHeight = config.selectHeight;
}
if(config.Ratio && config.Ratio > 0){
szyFile.Ratio = config.Ratio;
}
if(dom) this.fileDom = dom;
if(prev) this.preview = prev;
this.fileOnchange(dom);
}
}代码调用如下
$(function(){var dom = $('#fileChange')[0];
var prev = $('.prevw')[0];
szyFile.init(dom,prev,{'Ratio':1.2,'selectWidth':400,'selectHeight':300});
});
附件下载地址：兼容IE6+ 以上大部分浏览器，特殊浏览器没有测试！