[DefaultValue(true)]
[Parameter]
public bool Visible { get; set; }

<div id="overviewDemoDropZone" class="card custom-drop-zone bg-light rounded-3 w-100 m-0">
    <span class="drop-file-icon mb-3"></span>
    <span>Drag and Drop File Here</span><span class="m-1">or</span>
    <button id="overviewDemoSelectButton" class="btn border-primary btn-primary m-1">Select File</button>
</div>

<DxFileInput Visible="FileInputVisible" 
             FilesUploading="OnFilesUploading"
             SelectedFilesChanged="SelectedFilesChanged"
             ExternalSelectButtonCssSelector="#overviewDemoSelectButton"
             ExternalDropZoneCssSelector="#overviewDemoDropZone"
             ExternalDropZoneDragOverCssClass="bg-light border-secondary text-dark" />

@code {
    bool FileInputVisible { get; set; } = false;

    protected void SelectedFilesChanged(IEnumerable<UploadFileInfo> files) {
        FileInputVisible = files.ToList().Count > 0;
        InvokeAsync(StateHasChanged);
    }
    async Task OnFilesUploading(FilesUploadingEventArgs args) {
        foreach (var file in args.Files) {
            /* The following code is intended for demonstration purposes only.
            Do not read a stream directly in memory to avoid performance and security-related issues. */
            using var stream = new System.IO.MemoryStream();
            await file.OpenReadStream(file.Size).CopyToAsync(stream);
        }
    }
}

.custom-drop-zone {
    padding: 0 !important;
    border-style: dashed !important;
    border-width: 2px !important;
    height: 230px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}
.custom-drop-zone svg {
    width: 42px;
    height: 42px;
}
.drop-file-icon {
    background-size: contain;
    mask-repeat: no-repeat;
    -webkit-mask-repeat: no-repeat;
    background-position: center center;
    background-color: currentColor;
    width: 48px;
    height: 48px;
    -webkit-mask-image: url("../images/icons/drop-file.svg");
    mask-image: url("../images/icons/drop-file.svg");
}