Form

The object the form edits. Set this or EditContext.

An explicit edit context. Set this or Model.

The form's name. Required on static pages, where it tells Blazor which form a POST belongs to; pair it with [SupplyParameterFromForm(FormName = "...")] on the model property.

Posts as multipart/form-data, which a FileUpload needs to send its files on static pages. Without it, a post sends only the file names.

Uses Blazor's enhanced form handling on static pages (no full page reload). Defaults to true.

Lets the browser check required fields, lengths and formats before posting. Defaults to true.

Replaces the default DataAnnotations validator, for example with a FluentValidation one.

How labels sit next to fields. Defaults to stacked.

Space between fields, in spacing steps. Defaults to 5.

Lays the fields out in up to this many columns (1 to 4). Defaults to 1. The form shows fewer when it's narrow, by its own width rather than the screen's, so the same form fits a page, a dialog and a drawer: two columns from 32rem, three from 48rem, four from 64rem. Fields take one column and anything else (text, errors, buttons, a Fieldset) the whole row; set ColSpan to change either.

Disables every field in the form. Disabled fields can't be changed or focused and aren't posted. Buttons are left as they are.

Makes every field read-only: shown and posted, but not changed, as on a page that shows a record before editing it. HTML has no read-only select, checkbox, radio or range, so a read-only Select, Combobox or MultiSelect shows its value in a read-only text field, and checkboxes, switches, radios, segments and sliders are disabled; their values post from hidden inputs.

Which fields are marked beside their labels: RequiredMark.Required (an asterisk on required fields, the default), RequiredMark.Optional ("(optional)" on the others) or RequiredMark.None. Whether a field is required still comes from [Required] or its own Required.

The fields and buttons.

Margin on all sides, in spacing steps (-16 to 16; one step = 4px).

Horizontal margin. When set, replaces Margin on this axis.

Vertical margin. When set, replaces Margin on this axis.

Top margin. When set, replaces MarginY and Margin on this side.

Bottom margin. When set, replaces MarginY and Margin on this side.

Margin at the start (left in left-to-right text, right in right-to-left). Replaces MarginX and Margin on this side.

Margin at the end (right in left-to-right text, left in right-to-left). Replaces MarginX and Margin on this side.

Width.

Minimum width.

Maximum width.

Whether to grow into free space inside a Stack, Row or Column: <Box Grow>.

Whether to shrink when space is short inside a Stack, Row or Column. Defaults to true; Shrink="false" keeps the size.

Starting size inside a Stack, before growing or shrinking.

Alignment across the parent's direction, overriding the parent's Align for this component only, such as a button lined up with the bottom of labeled fields in a Row.

How many columns it spans in a Form or Fieldset with Columns, or a Grid; GridSpan.Full for the whole row. Never more than the columns shown, so a form that narrows to one column needs no breakpoints.

Starts a new row in a Form or Fieldset with Columns, or a Grid, leaving the rest of the row before it empty.

Extra CSS classes, merged after the component's own classes.

Inline style, appended after the component's generated custom properties.

Hides the component from this breakpoint up, such as a menu button only phones need.

Shows the component only from this breakpoint up, such as header links for wide screens.

Runs on the server after a submit that passes validation.

Runs on the server after a submit that fails validation.

Runs on every submit, instead of the valid and invalid callbacks. You validate yourself.