2

我需要更改此代码，以便条件检查来自多个选择文件输入的所有选定文件的文件扩展名，此代码仅检查一个。我有什么办法可以做到这一点？

var file = document.getElementById('file');
var ext = file.value.substring(file.value.lastIndexOf('.') + 1);

     if(ext!== "mp4" && ext!== "m4v" && ext!== "f4v")  {
         alert('not an accepted file extension');
             return false;
} 

<input id="file" name="uploaded[]" type="file" multiple />
4

5 回答 5

9

请注意，我只费心获取字符串的最后三个字符，因为您只有三个字母的文件扩展名。如果您愿意，可以使用.split('.')获取一个段数组并选择该数组的最后一个元素。

var selection = document.getElementById('file');
for (var i=0; i<selection.files.length; i++) {
    var ext = selection.files[i].name.substr(-3);
    if(ext!== "mp4" && ext!== "m4v" && ext!== "fv4")  {
        alert('not an accepted file extension');
        return false;
    }
}
于 2013-01-18T00:59:10.737 回答
1

要获取 dom 元素数组中的所有输入元素，请使用document.getElementsByName('uploaded[]').

例如，在您的情况下，它将类似于：

var files = document.getElementsByName('uploaded[]'); 
for (var i = 0, j = files.length; i < j; i++) {
    var file = files[i];
    // do stuff with your file
}
于 2013-01-18T00:53:08.487 回答
1

通过 javascript some()方法验证多个文件。

function isVideo(film) {
  const ext = ['.mp4', '.m4v', '.fv4'];
  return ext.some(el => film.endsWith(el));
}

function fileValidation() {
  let files = document.getElementById('file');
  for (let i = 0; i < files.files.length; ++i) {
    let fname = files.files.item(i).name;
    if (!isVideo(fname)) {
      alert("File extension not supported!");
      return false;
    }
  }
}
<input id="file" name="uploaded[]" type="file" multiple onchange="fileValidation()" />

于 2020-08-12T03:51:08.207 回答
0 
  <input name="" id="yourinputfieldis"  onchange="checkFile()"  type="file" multiple = "multiple" accept = "*">    

  <script>
        function checkFile() {   
        var x =  document.getElementById("yourinputfieldis");
        var txt = "";
        document.getElementById("demo").innerHTML = txt;
        if ('files' in x) {
        if (x.files.length == 0) {
        txt = "Select one or more files.";
        } else {
        for (var i = 0; i < x.files.length; i++) {      

        var file = x.files[i];
        if ('name' in file) {

        var ext = file.name.split('.').pop().toLowerCase();
        if($.inArray(ext, ['gif','png','jpg','jpeg','doc','pdf','xlsx']) == -1) {
        txt += "name: " + file.name + "<br>";
        document.getElementById("yourinputfieldis").value = "";

        if ('size' in file) {
        txt += "size: " + file.size + " bytes <br>";
        }
        alert('You are trying to upload files which not allowed ' + "(" + file.name + " is invalid)");

        }

        }
        }
        }
        }
        else {
        if (x.value == "") {
        txt += "Select one or more files.";
        } else {
        txt += "The files property is not supported by your browser!";
        txt  += "<br>The path of the selected file: " + x.value; 
        }
        }     
        }
   </script>
于 2016-07-13T11:25:37.140 回答
0

使用此方法验证 aspx 页面中的文件类型，

<asp:FileUpload ID="fupload" name="fupload" runat="server" Class="form-control multi" accept="doc|docx|pdf|xls|xlsx" Width="270px" />

我已经使用“MultiFile.js”插件来选择多个文件并上传。

于 2018-07-02T15:36:35.533 回答