这几天一直在解决一个问题，上传图片时选择成功后就能预览。
需求：在点击上传图标的时候会在前面的input框中显示出文件名，然后点击后面的查看按钮就可以预览选择的这张图片了，要求不能刷新页面
1.一开始的时候打算用ajax上传，后来发现多张图片一同上传的时候会出现问题，ajax上传图片的原理是当你选中一张图片的时候会使用js在这个type为file的input的框外面包上一个form表单然后通过ajaxSubmit自动提交到php文件，之后通过php文件进行上传，最后返回一个上传到服务器的图片路径，点击查看的时候就可以获取到这个图片，实际上这个时候图片已经上传到服务器了。但这个需求是多张图片，这么做会出现很大的问题。
2.之后在网上查到了使用js实时预览本地选中的图片，这个和ajax上传的不同就是，在选择完图片文件之后并不会上传到服务器，而是直接调取本机图片的路径预览。下面就是用这种方法实现最终效果的例子。
方法：
首先需要一个上传文件的input的框
然后在下面加一个获取它的本地图片路径的隐藏形式的input的框
//图片上传预览https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/IE是用了滤镜。
https://www.mshxw.com/file/tupian/20210924/functionhttps://www.mshxw.com/file/tupian/20210924/previewImage(file)
https://www.mshxw.com/file/tupian/20210924/{
https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/ifhttps://www.mshxw.com/file/tupian/20210924/(file.fileshttps://www.mshxw.com/file/tupian/20210924/&&https://www.mshxw.com/file/tupian/20210924/file.files[0])
https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/{
https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/varhttps://www.mshxw.com/file/tupian/20210924/readerhttps://www.mshxw.com/file/tupian/20210924/=https://www.mshxw.com/file/tupian/20210924/newhttps://www.mshxw.com/file/tupian/20210924/FileReader();
https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/reader.onloadhttps://www.mshxw.com/file/tupian/20210924/=https://www.mshxw.com/file/tupian/20210924/function(evt){
https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/$(file).next().val(evt.target.result);
https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/}
https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/reader.readAsDataURL(file.files[0]);
https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/}
https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/elsehttps://www.mshxw.com/file/tupian/20210924///兼容IE
https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/{
https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/varhttps://www.mshxw.com/file/tupian/20210924/sFilter='filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(sizingMethod=scale,src="';
https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/file.select();
https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/varhttps://www.mshxw.com/file/tupian/20210924/srchttps://www.mshxw.com/file/tupian/20210924/=https://www.mshxw.com/file/tupian/20210924/document.selection.createRange().text;
https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924///p.innerHTMLhttps://www.mshxw.com/file/tupian/20210924/=https://www.mshxw.com/file/tupian/20210924/'';
https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924///varhttps://www.mshxw.com/file/tupian/20210924/imghttps://www.mshxw.com/file/tupian/20210924/=https://www.mshxw.com/file/tupian/20210924/document.getElementById('imghead');
https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924///img.filters.item('DXImageTransform.Microsoft.AlphaImageLoader').srchttps://www.mshxw.com/file/tupian/20210924/=https://www.mshxw.com/file/tupian/20210924/src;
https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/$(this).next().val(src);
https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924///varhttps://www.mshxw.com/file/tupian/20210924/recthttps://www.mshxw.com/file/tupian/20210924/=https://www.mshxw.com/file/tupian/20210924/clacImgZoomParam(MAXWIDTH,https://www.mshxw.com/file/tupian/20210924/MAXHEIGHT,https://www.mshxw.com/file/tupian/20210924/img.offsetWidth,https://www.mshxw.com/file/tupian/20210924/img.offsetHeight);
https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924///statushttps://www.mshxw.com/file/tupian/20210924/=('rect:'+rect.top+','+rect.left+','+rect.width+','+rect.height);
https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924///p.innerHTMLhttps://www.mshxw.com/file/tupian/20210924/=https://www.mshxw.com/file/tupian/20210924/"";
https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/}
https://www.mshxw.com/file/tupian/20210924/}
https://www.mshxw.com/file/tupian/20210924/functionhttps://www.mshxw.com/file/tupian/20210924/clacImgZoomParam(https://www.mshxw.com/file/tupian/20210924/maxWidth,https://www.mshxw.com/file/tupian/20210924/maxHeight,https://www.mshxw.com/file/tupian/20210924/width,https://www.mshxw.com/file/tupian/20210924/heighthttps://www.mshxw.com/file/tupian/20210924/){
https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/varhttps://www.mshxw.com/file/tupian/20210924/paramhttps://www.mshxw.com/file/tupian/20210924/=https://www.mshxw.com/file/tupian/20210924/{top:0,https://www.mshxw.com/file/tupian/20210924/left:0,https://www.mshxw.com/file/tupian/20210924/width:width,https://www.mshxw.com/file/tupian/20210924/height:height};
https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/if(https://www.mshxw.com/file/tupian/20210924/width>maxWidthhttps://www.mshxw.com/file/tupian/20210924/||https://www.mshxw.com/file/tupian/20210924/height>maxHeighthttps://www.mshxw.com/file/tupian/20210924/)
https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/{
https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/rateWidthhttps://www.mshxw.com/file/tupian/20210924/=https://www.mshxw.com/file/tupian/20210924/widthhttps://www.mshxw.com/file/tupian/20210924//https://www.mshxw.com/file/tupian/20210924/maxWidth;
https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/rateHeighthttps://www.mshxw.com/file/tupian/20210924/=https://www.mshxw.com/file/tupian/20210924/heighthttps://www.mshxw.com/file/tupian/20210924//https://www.mshxw.com/file/tupian/20210924/maxHeight;
https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/
https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/if(https://www.mshxw.com/file/tupian/20210924/rateWidthhttps://www.mshxw.com/file/tupian/20210924/>https://www.mshxw.com/file/tupian/20210924/rateHeighthttps://www.mshxw.com/file/tupian/20210924/)
https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/{
https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/param.widthhttps://www.mshxw.com/file/tupian/20210924/=https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/maxWidth;
https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/param.heighthttps://www.mshxw.com/file/tupian/20210924/=https://www.mshxw.com/file/tupian/20210924/Math.round(heighthttps://www.mshxw.com/file/tupian/20210924//https://www.mshxw.com/file/tupian/20210924/rateWidth);
https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/}else
https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/{
https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/param.widthhttps://www.mshxw.com/file/tupian/20210924/=https://www.mshxw.com/file/tupian/20210924/Math.round(widthhttps://www.mshxw.com/file/tupian/20210924//https://www.mshxw.com/file/tupian/20210924/rateHeight);
https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/param.heighthttps://www.mshxw.com/file/tupian/20210924/=https://www.mshxw.com/file/tupian/20210924/maxHeight;
https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/}
https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/}
https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/
https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/param.lefthttps://www.mshxw.com/file/tupian/20210924/=https://www.mshxw.com/file/tupian/20210924/Math.round((maxWidthhttps://www.mshxw.com/file/tupian/20210924/-https://www.mshxw.com/file/tupian/20210924/param.width)https://www.mshxw.com/file/tupian/20210924//https://www.mshxw.com/file/tupian/20210924/2);
https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/param.tophttps://www.mshxw.com/file/tupian/20210924/=https://www.mshxw.com/file/tupian/20210924/Math.round((maxHeighthttps://www.mshxw.com/file/tupian/20210924/-https://www.mshxw.com/file/tupian/20210924/param.height)https://www.mshxw.com/file/tupian/20210924//https://www.mshxw.com/file/tupian/20210924/2);
https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/https://www.mshxw.com/file/tupian/20210924/returnhttps://www.mshxw.com/file/tupian/20210924/param;
https://www.mshxw.com/file/tupian/20210924/}可以看到在选择图片的时候调用了previewImage（）方法，使用这个方法获取了本机图片的地址传入到class为imageurl的input框中。
之后是创建一个查看按钮，我是在
下面直接加了一个按钮，当点击这个按钮的时候获取$(this).prev().val()，然后传给想要显示图片的p中的img里，这样图片就显示出来了
经过测试这个方法可以满足firefox，chrome，ie10以上，基本上已经够用了吧。
压了几天得问题没想到就这么解决了，效率不高，积累经验！积累经验！积累经验！
以上就是php上传多张图片时，选择图片后即可预览的问题的详细内容，更多请关注考高分网其它相关文章！
