FileUpload

The form field name the files post under. On static pages, name the page property the same (or use [SupplyParameterFromForm(Name = "...")]).

The visible label.

Hides the label but keeps it for screen readers.

Help text under the zone.

Whether a file must be chosen before the form posts.

Disables the picker.

The file types to offer, as the accept attribute: "image/*", ".pdf,.docx". A hint for the picker only; check types on the server too.

Allows choosing several files.

The largest file allowed, in bytes. With JavaScript, larger files are flagged before the form posts. Always check on the server too, and set the server's request size limit to match.

On interactive pages, the most files OnChange receives; extra ones are left out. Defaults to 10.

The message for a file over MaxFileSize: {0} is its name, {1} the limit.

The message for a chosen or dropped file that doesn't match Accept: {0} is its name. (The picker's "All files" option and drops both get past the type filter.)

The link that opens the picker. Defaults to "Choose a file" ("Choose files" with Multiple).

The text after the link. Defaults to "or drag it here" ("or drag them here" with Multiple). Not shown on touch screens, where dragging isn't an option.

Small text under the prompt. Defaults to the types and size allowed, from Accept and MaxFileSize: "PNG or JPG · up to 2 MB". An empty string shows none. With JavaScript, the chosen file's name and size take its place.

The zone's icon. Defaults to an arrow out of a tray.

Validation messages to show under the zone, such as from server checks.

On interactive pages, runs with the chosen files, leaving out any over MaxFileSize (the zone flags those). Read one with OpenReadStream(MaxFileSize): its default limit is 500 KB.