javascript - 如果给定的文件格式错误，则重置输入文件

Question

如果文件格式不是图像格式，如何将输入文件设置回“未选择文件”？

<input type="file" name="image" id="image" value="" class="form-control" />

<script>
$("#image").change(function()
{
    var Data = document.getElementById('image');
    var FileUploadPath = Data.value;

    if (FileUploadPath != '') {
        var Extension = FileUploadPath.substring(FileUploadPath.lastIndexOf('.') + 1).toLowerCase();
        //The file uploaded is an image

        if (Extension == "gif" || Extension == "png" || Extension == "bmp"
                            || Extension == "jpeg" || Extension == "jpg"){
            return true;
        }else if (Extension != 'gif' || Extension != 'png' || Extension != 'bmp' || Extension != 'jpeg' || Extension != 'jpg') {

            alert("Photo only allows file types of GIF, PNG, JPG, JPEG and BMP. ");
            return false;
        }
    }
}); 
</script>

Answer 1

$("#image").change(function()
{
    var Data = document.getElementById('image');
    var FileUploadPath = Data.value;

    if (FileUploadPath != '') {
        var Extension = FileUploadPath.substring(FileUploadPath.lastIndexOf('.') + 1).toLowerCase();
        //The file uploaded is an image

        if (Extension == "gif" || Extension == "png" || Extension == "bmp"
                            || Extension == "jpeg" || Extension == "jpg"){
            return true;
        }else if (Extension != 'gif' || Extension != 'png' || Extension != 'bmp' || Extension != 'jpeg' || Extension != 'jpg') {

            alert("Photo only allows file types of GIF, PNG, JPG, JPEG and BMP. ");
          Data.type = '';
          Data.type = 'file';
            return false;
        }
    }
});

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<input type="file" name="image" id="image" value="" class="form-control" />