A binding to an optional source of truth for the sheet.
シートに対するある随意の信頼できる情報源へのあるバインディング。
When item is non-nil, the system passes the contents to the modifier’s closure. You display this content in a sheet that you create that the system displays to the user. If item changes, the system dismisses the currently displayed sheet and replaces it with a new one using the same process.
onDismiss
The closure to execute when dismissing the modal view.
content
A closure returning the content of the modal view.
モーダルビューの内容を返しているクロージャ。
Discussion
議論
Use this method to display a modal view that covers as much of the screen as possible. In the example below a custom structure — CoverData — provides data for the full-screen view to display in the content closure when the user clicks or taps the “Present Full-Screen Cover With Data” button: