Validate image/* on drop

21 Dec 20223 minutes to read

The uploader control allows you to select all types of images using the *image/ ** to allowedExtensions property. You can directly set it to accept the attribute of uploader element.

By default, it is working fine when you select a file by clicking the browse button. But, this behavior is not supported to drag and drop the files for selection.

CSHTML

@{
    var asyncSettings = new Syncfusion.EJ2.Inputs.UploaderAsyncSettings { SaveUrl = "https://services.syncfusion.com/aspnet/production/api/FileUploader/Save", RemoveUrl = "https://services.syncfusion.com/aspnet/production/api/FileUploader/Remove" };
}
<div class="control_wrapper">
    <div id='preview'></div>
    <ejs-uploader id="fileupload" autoUpload="false" allowedExtensions="image/*" selected="onSelect" asyncSettings="@asyncSettings">
    </ejs-uploader>
</div>
<script>

    function onSelect(args) {
        var uploadObj = document.getElementById("fileupload").ej2_instances[0];
        if (event.type === 'drop') {
            var allImages = ['png', 'jpg', 'jpeg', 'gif', 'tiff', 'bpg'];
            var files = args.filesData;
            var modifiedFiles = [];
            for (var i = 0; i < files.length; i++) {
                var file = files[i];
                if (allImages.indexOf(file.type) === -1) {
                    file.status = 'File type is not allowed';
                    file.statusCode = '0';
                }
                modifiedFiles.push(file);
            }
            args.isModified = true;
            args.modifiedFilesData = modifiedFiles.concat(uploadObj.filesData);
        }
    }

</script>

Index.css

.control_wrapper {
	max-width: 505px;
	margin: auto;
}

NOTE

You can also explore ASP.NET Core File Upload feature tour page for its groundbreaking features. You can also explore our ASP.NET Core File Upload example to understand how to browse the files which you want to upload to the server.