Blazor Dropdown List Example - Popup Resize

This example demonstrates template and custom resizing functionality of the DropDownList component. It shows how to customize the visual presentation of list items and the displayed value, and how to enable a resizable popup so users can adjust the dropdown dimensions to their preference.

Template options let you control specific fragments of the component while preserving built-in interaction behavior:

• ItemTemplate — Customize list item content (icons, supplementary metadata, or formatted text) to match design and accessibility requirements.
• HeaderTemplate — Provide a tailored header for the popup for grouping, labeling, or non-interactive descriptive content.
• ValueTemplate — Control how the selected item is rendered in the input area so the displayed value aligns with the item presentation.

Resize features enable precise visual control of the popup:

• AllowResize — set to true to enable resizing.
• Drag the resize handle in the popup’s bottom-right corner to change width and height.
• Adjust dimensions to suit layout constraints or user preference, improving visual management of long lists or dense content.

When combining templates and resize behavior, maintain semantic markup and appropriate ARIA attributes, avoid embedding conflicting interactive controls inside templates, and test keyboard navigation and screen-reader behavior to ensure accessibility and predictable interaction.