jquery - 上传前检查文件扩展名

Question

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

Bur没有得到适当的结果.谁能告诉我怎么能这样做？

提前致谢...

Answer 1

如果你想在没有插件的情况下这样做,你可以使用以下内容.

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>

Answer 2

您可以使用JQuery实现此目的

HTML

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

JQuery的

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

有关详细信息,请单击此处

Answer 3

我要感谢发布答案的人,但他已删除了帖子.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;
        }
    }
});

谢谢你的回答,它真的有用......

Answer 4

这是一个简单的javascript验证代码,验证后会清理输入文件.

<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("");
    }
}

Answer 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(', '));
    }

});