I have a dropdown with too many choices to scroll, so I'd like to spread them out through multiple columns and save 'real estate' on my screen - something like https://cdn.mescius.io/assets/developer/blogs/legacy/wijmo/2016/01/MultiColumn_02.png
... Is this possible in Radzen or should I be thinking of css/js?
There is no such option available out-of-the-box however you can create your own popup component with desired layout. For example:
@using RadzenBlazorDemos.Data
@using RadzenBlazorDemos.Models.Northwind
@using Microsoft.EntityFrameworkCore
@using Radzen.Blazor.Rendering
@inherits DbContextPage
@inject IJSRuntime JSRuntime
<RadzenButton @ref=button Text="Select customers" Click="@(args => popup.ToggleAsync(button.Element))" />
<Popup @ref=popup Lazy=true
Style="display:none;position:absolute;height:300px;width:600px;padding:5px;border:var(--rz-panel-border);background-color:var(--rz-panel-background-color);">
<RadzenCheckBoxList TValue="string" Data="@dbContext.Customers" style="height:100%;overflow:auto;background:white;"
TextProperty="CompanyName" ValueProperty="CustomerID" @bind-Value=ids />
</Popup>
@code {
RadzenButton button;
Popup popup;
IEnumerable<string> ids = new [] { "ALFKI", "AROUT"};
}
If you set width also you will have aligned checkboxes:
