英数字のみ TextField ( "Input" , text : $input ) . onChange ( of : input , perform : filter ) func filter ( value : String ) { let validCodes = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ" let sets = CharacterSet ( charactersIn : validCodes) input = String (value. unicodeScalars . filter (sets. contains ). map ( Character . init )) if 10 < input . count { input = String ( input . prefix ( 10 )) } } https://zenn.dev/yorifuji/articles/swiftui-textfield-filter