input type=file实现图片上传

<label for="file">
    <img src="data:images/morende.jpg" alt="">
    <span>点击更换头像</span>
</label>
<input type="file" name="file" id="file" accept="image/*" value="" hidden=""/>

$("input[type='file']").change( function(event) {//上传图片
　　console.log(event)
       var file = event.currentTarget.files[0]
        var formFile = new FormData();
        formFile.append("file", file); 

        $.ajax({
            url: ajaxURL+'/currency/istImage',
            type: 'POST',
            data: formFile,
            async: true,
            cache: false,
            contentType: false,
            processData: false,
            dataType:'json',
            success: function(res) {
                console.log(res);
            }
        })

    });

或者循环多个上传

<input type="file" onchange="upload(this)">
<script>

function upload(obj){
var files = obj.files ;
var formData = new FormData();
for(var i = 0;i<files.length;i++){
formData.append("upfile[]", files[i]);

}
$.ajax({
url: "1.php",
type: "POST",
data:formData,
cache:false, //不设置缓存
processData: false, // 不处理数据
contentType: false // 不设置内容类型
});
}

</script>