29

我正在使用 uploadify 使用Codeigniter上传文件。在上传文件之前，我只需要检查文件扩展名是否正确。我试过http://jquery.bassistance.de/和http://forum.jquery.com/

Bur没有得到正确的结果。谁能告诉我我该怎么做？

提前致谢...

4

9 回答 9

54

您可以使用 JQuery 来实现这一点

HTML

 <input type="file" id="FilUploader" />

jQuery

    $("#FilUploader").change(function () {
        var fileExtension = ['jpeg', 'jpg', 'png', 'gif', 'bmp'];
        if ($.inArray($(this).val().split('.').pop().toLowerCase(), fileExtension) == -1) {
            alert("Only formats are allowed : "+fileExtension.join(', '));
        }
    });

更多信息请点击这里

于 2015-05-05T10:30:42.037 回答
43

如果您想在没有插件的情况下执行此操作，可以使用以下内容。

Javascript，使用 jQuery：

$(document).ready( function (){
    $("#your_form").submit( function(submitEvent) {

        // get the file name, possibly with path (depends on browser)
        var filename = $("#file_input").val();

        // Use a regular expression to trim everything before final dot
        var extension = filename.replace(/^.*\./, '');

        // Iff there is no dot anywhere in filename, we would have extension == filename,
        // so we account for this possibility now
        if (extension == filename) {
            extension = '';
        } else {
            // if there is an extension, we convert to lower case
            // (N.B. this conversion will not effect the value of the extension
            // on the file upload.)
            extension = extension.toLowerCase();
        }

        switch (extension) {
            case 'jpg':
            case 'jpeg':
            case 'png':
                alert("it's got an extension which suggests it's a PNG or JPG image (but N.B. that's only its name, so let's be sure that we, say, check the mime-type server-side!)");

            // uncomment the next line to allow the form to submitted in this case:
//          break;

            default:
                // Cancel the form submission
                submitEvent.preventDefault();
        }

  });
});

HTML：

<form id="your_form" method="post" enctype="multipart/form-data">
    <input id="file_input" type="file" />
    <input type="submit">
</form>
于 2013-02-13T11:51:45.933 回答
22

我要感谢发布答案的人，但他已删除该帖子。我们可以这样做。

$("#yourElem").uploadify({
   'uploader': ...,
   'script': ...
    'fileExt' : '*.jpg;*.gif;', //add allowed extensions
    .....,
    'onSelect': function(e, q, f) {
        var validExtensions = ['jpg','gif']; //array of valid extensions
        var fileName = f.name;
        var fileNameExt = fileName.substr(fileName.lastIndexOf('.') + 1);
        if ($.inArray(fileNameExt, validExtensions) == -1){
           alert("Invalid file type");
           $("#yourElem").uploadifyCancel(q);
           return false;
        }
    }
});

感谢您的回答，它确实有效...

于 2013-02-13T11:41:39.087 回答
7

这是一个用于 javascript 验证的简单代码，验证后它将清理输入文件。

<input type="file" id="image" accept="image/*" onChange="validate(this.value)"/>

function validate(file) {
    var ext = file.split(".");
    ext = ext[ext.length-1].toLowerCase();      
    var arrayExtensions = ["jpg" , "jpeg", "png", "bmp", "gif"];

    if (arrayExtensions.lastIndexOf(ext) == -1) {
        alert("Wrong extension type.");
        $("#image").val("");
    }
}
于 2016-01-20T13:35:31.237 回答
5 
 $("#file-upload").change(function () {

    var validExtensions = ["jpg","pdf","jpeg","gif","png"]
    var file = $(this).val().split('.').pop();
    if (validExtensions.indexOf(file) == -1) {
        alert("Only formats are allowed : "+validExtensions.join(', '));
    }

});
于 2019-09-01T17:30:11.220 回答
4 
<!DOCTYPE html>
    <html>
      <head>
      <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
      <script>
         jQuery(document).ready(function(){
               jQuery('.form-file input').each(function () {
                     $this = jQuery(this);
                          $this.on('change', function() {
                               var fsize = $this[0].files[0].size,
                                   ftype = $this[0].files[0].type,
                                   fname = $this[0].files[0].name,
                                   fextension = fname.substring(fname.lastIndexOf('.')+1);
                                   validExtensions = ["jpg","pdf","jpeg","gif","png","doc","docx","xls","xlsx","ppt","pptx","txt","zip","rar","gzip"];

                                if ($.inArray(fextension, validExtensions) == -1){
                                    alert("This type of files are not allowed!");
                                    this.value = "";
                                    return false;
                                }else{
                                    if(fsize > 3145728){/*1048576-1MB(You can change the size as you want)*/
                                        alert("File size too large! Please upload less than 3MB");
                                        this.value = "";
                                        return false;
                                    }
                                    return true;
                               }

                         });
             });
       });
    </script>
    </head>

<body>
    <form>
          <div class="form-file">
               <label for="file-upload" class="from-label">File Upload</label>
               <input class="form-control" name="file-upload" id="file-upload" type="file">
          </div>
    </form>
</body>

</html>

这是检查文件大小和文件扩展名的完整答案。这使用了默认文件输入字段和 jQuery 库。工作示例：https ://jsfiddle.net/9pfjq6zr/2/

于 2018-08-02T09:02:44.400 回答
3

以下代码允许上传 gif、png、jpg、jpeg 和 bmp 文件。

var extension = $('#your_file_id').val().split('.').pop().toLowerCase();

if($.inArray(extension, ['gif','png','jpg','jpeg','bmp']) == -1) {
    alert('Sorry, invalid extension.');
    return false;
}
于 2017-04-23T17:02:48.193 回答
1

如果您不想使用$(this).val()，可以尝试：

var file_onchange = function () {
  var input = this; // avoid using 'this' directly

  if (input.files && input.files[0]) {
    var type = input.files[0].type; // image/jpg, image/png, image/jpeg...

    // allow jpg, png, jpeg, bmp, gif, ico
    var type_reg = /^image\/(jpg|png|jpeg|bmp|gif|ico)$/;

    if (type_reg.test(type)) {
      // file is ready to upload
    } else {
      alert('This file type is unsupported.');
    }
  }
};

$('#file').on('change', file_onchange);

希望这可以帮助！

于 2017-02-23T21:43:25.170 回答
0 
        function yourfunctionName() {
            var yourFileName = $("#yourinputfieldis").val();

            var yourFileExtension = yourFileName .replace(/^.*\./, '');
            switch (yourFileExtension ) {
                case 'pdf':
                case 'jpg':
                case 'doc':
                    $("#formId").submit();// your condition what you want to do
                    break;
                default:
                    alert('your File extension is wrong.');
                    this.value = '';
            }    
        }
于 2015-12-03T13:25:31.393 回答