DragnDropCommon.razor

@using System.IO;
@inject IFileReaderService fileReaderService
<h1>Hello, dropped files!</h1>

Welcome to your new filestreaming app.
<br />
This demo reads files that was dropped in without doing anything particular with it.
<br />
<br />
<div class="btn-group btn-group-toggle">
    @foreach (var item in possibleOptions)
    {
        <label class="@defaultClasses @(item.IsActive() ? "active":"")" @key="item.Id">
            <input type="radio" name="options" id="@item.Id" autocomplete="off" checked="@(item.IsActive() ? "checked":"")" @onclick="_ => OnChange(item.Id)"> @item.Description
        </label>
    }
</div>
<br />
<br />

@if (currentOption == "DragnDropDivCommon")
{
    <DragnDropDivCommon />
}
else if (currentOption == "DragnDropInputCommon")
{
    <DragnDropInputCommon />
}

@code {
    public static string WriteFileInfoOutput(IFileInfo fileInfo, string nl) {
        var output = string.Empty;
        output += $"{nameof(IFileInfo)}.{nameof(fileInfo.Name)}: {fileInfo?.Name}{nl}";
        output += $"{nameof(IFileInfo)}.{nameof(fileInfo.Size)}: {fileInfo?.Size}{nl}";
        output += $"{nameof(IFileInfo)}.{nameof(fileInfo.Type)}: {fileInfo?.Type}{nl}";
        output += $"{nameof(IFileInfo)}.{nameof(fileInfo.LastModifiedDate)}: {fileInfo?.LastModifiedDate?.ToString() ?? "(N/A)"}{nl}";
        output += fileInfo?.NonStandardProperties?.Keys.Aggregate(output, (current, property) => current + $"{nameof(IFileInfo)}.{property} (nonstandard): {fileInfo.NonStandardProperties[property]}{nl}");
        output += $"Reading file...{nl}";
        return output;
    }
    private class PossibleOption { public string Id { get; set; } public string Description { get; set; } public Func<bool> IsActive { get; set; } }
    List<PossibleOption> possibleOptions = new List<PossibleOption> {
        new PossibleOption { Id = "DragnDropDivCommon", Description= "Drag and Drop on Element" },
        new PossibleOption { Id = "DragnDropInputCommon", Description= "Drag and Drop on Hidden input" },
    };

    string defaultClasses = "btn btn-primary";
    string currentOption;
    protected override void OnInitialized()
    {
        currentOption = possibleOptions.First().Id;
        foreach (var item in possibleOptions)
        {
            item.IsActive = () => currentOption == item.Id;

        }
        base.OnInitialized();
    }

    public void OnChange(string id)
    {
        currentOption = id;
        StateHasChanged();
    }

}