javascript - 我在下面一直不确定

Question

我试图在用户上传文件后显示文件名。该文件成功上传，但在 javascript 中，它一直附加在“未定义”列表中。为什么它一直显示“未定义”而不是从文件输入上传的文件名？？：

以下是上传后显示文件名和消息的代码：

function stopImageUpload(success){

    function handleFileSelect(evt) {
    var files = evt.target.files;
    localStorage["fname"] = files[0].name; //save the name for future use
}

$('.fileImage').bind('change', handleFileSelect, false);


      var result = '';
      if (success == 1){
  result = '<span class="msg">The file ('+localStorage["fname"]+') was uploaded successfully!</span><br/><br/>';
    localStorage["fname"] = undefined; //remove the temporary variable

      }
      else {
         result = '<span class="emsg">There was an error during file upload!</span><br/><br/>';
      }

      return true;   
}

下面是表格：

  <form action='imageupload.php' method='post' enctype='multipart/form-data' target='upload_target' onsubmit='stopImageUpload(this);' class='imageuploadform' >
    <p>Image File: <input name='fileImage' type='file' class='fileImage' />
    <input type='submit' name='submitImageBtn' class='sbtnimage' value='Upload' />
    </p> 
    <ul class='list'></ul>
    </form>

Answer 1

尝试分解你的功能。在处理表单提交的函数之外绑定更改事件。

$(document).ready(function(){
    $('.fileImage').bind('change', handleFileSelect, false);
});

function handleFileSelect(evt) {
    var files = evt.target.files;
    localStorage["fname"] = files[0].name; //save the name for future use
}
function stopImageUpload(success){
      var result = '';
      if (success == 1){
  result = '<span class="msg">The file ('+localStorage["fname"]+') was uploaded successfully!</span><br/><br/>';
    localStorage["fname"] = undefined; //remove the temporary variable

      }
      else {
         result = '<span class="emsg">There was an error during file upload!</span><br/><br/>';
      }

      return true;   
}