shadcn（shadcn/ui 组件）

shadcn/ui Development

This skill provides guidance for building interfaces with shadcn/ui, focusing on always using the latest version and modern patterns.

Philosophy: Copy and own your components. Use the new-york style. Leverage Radix UI primitives for accessibility.

Quick Reference

Installation

Initialize in Next.js

npx shadcn@latest init

Configuration prompts:

• Style: new-york (recommended)
• Base color: neutral, slate, zinc, gray, or stone
• CSS variables: Yes (recommended)

Add Components

# Add individual components
npx shadcn@latest add button
npx shadcn@latest add card dialog form input

# Add multiple components
npx shadcn@latest add button card dialog form input label textarea

The cn() Utility

Merge Tailwind classes conditionally:

import { cn } from "@/lib/utils"

interface ButtonProps extends React.ButtonHTMLAttributes<HTMLButtonElement> {
  variant?: 'default' | 'destructive' | 'outline'
  size?: 'sm' | 'md' | 'lg'
}

export function Button({
  className,
  variant = 'default',
  size = 'md',
  ...props
}: ButtonProps) {
  return (
    <button
      className={cn(
        // Base styles
        "inline-flex items-center justify-center rounded-md font-medium transition-colors",
        "focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring",
        "disabled:pointer-events-none disabled:opacity-50",

        // Variants
        variant === 'default' && "bg-primary text-primary-foreground hover:bg-primary/90",
        variant === 'destructive' && "bg-destructive text-destructive-foreground hover:bg-destructive/90",
        variant === 'outline' && "border border-input bg-background hover:bg-accent hover:text-accent-foreground",

        // Sizes
        size === 'sm' && "h-8 px-3 text-xs",
        size === 'md' && "h-10 px-4 text-sm",
        size === 'lg' && "h-12 px-6 text-base",

        // Custom classes
        className
      )}
      {...props}
    />
  )
}

Core Components

Button

import { Button } from "@/components/ui/button"

// Variants
<Button>Default</Button>
<Button variant="secondary">Secondary</Button>
<Button variant="outline">Outline</Button>
<Button variant="ghost">Ghost</Button>
<Button variant="link">Link</Button>
<Button variant="destructive">Destructive</Button>

// Sizes
<Button size="sm">Small</Button>
<Button size="default">Default</Button>
<Button size="lg">Large</Button>
<Button size="icon"><IconSearch /></Button>

// States
<Button disabled>Disabled</Button>
<Button asChild>
  <Link href="/about">As Link</Link>
</Button>

Card

import {
  Card,
  CardContent,
  CardDescription,
  CardFooter,
  CardHeader,
  CardTitle,
} from "@/components/ui/card"

<Card>
  <CardHeader>
    <CardTitle>Card Title</CardTitle>
    <CardDescription>Card description goes here</CardDescription>
  </CardHeader>
  <CardContent>
    <p>Card content</p>
  </CardContent>
  <CardFooter>
    <Button>Action</Button>
  </CardFooter>
</Card>

Dialog

import {
  Dialog,
  DialogContent,
  DialogDescription,
  DialogFooter,
  DialogHeader,
  DialogTitle,
  DialogTrigger,
  DialogClose,
} from "@/components/ui/dialog"

<Dialog>
  <DialogTrigger asChild>
    <Button>Open Dialog</Button>
  </DialogTrigger>
  <DialogContent>
    <DialogHeader>
      <DialogTitle>Are you sure?</DialogTitle>
      <DialogDescription>
        This action cannot be undone.
      </DialogDescription>
    </DialogHeader>
    <div className="py-4">
      Dialog body content
    </div>
    <DialogFooter>
      <DialogClose asChild>
        <Button variant="outline">Cancel</Button>
      </DialogClose>
      <Button>Confirm</Button>
    </DialogFooter>
  </DialogContent>
</Dialog>

Input & Label

import { Input } from "@/components/ui/input"
import { Label } from "@/components/ui/label"

<div className="grid gap-2">
  <Label htmlFor="email">Email</Label>
  <Input
    id="email"
    type="email"
    placeholder="you@example.com"
  />
</div>

Select

import {
  Select,
  SelectContent,
  SelectItem,
  SelectTrigger,
  SelectValue,
} from "@/components/ui/select"

<Select>
  <SelectTrigger className="w-[200px]">
    <SelectValue placeholder="Select option" />
  </SelectTrigger>
  <SelectContent>
    <SelectItem value="option1">Option 1</SelectItem>
    <SelectItem value="option2">Option 2</SelectItem>
    <SelectItem value="option3">Option 3</SelectItem>
  </SelectContent>
</Select>

Form Handling

With React Hook Form + Zod

'use client'

import { useForm } from "react-hook-form"
import { zodResolver } from "@hookform/resolvers/zod"
import * as z from "zod"
import { Button } from "@/components/ui/button"
import {
  Form,
  FormControl,
  FormDescription,
  FormField,
  FormItem,
  FormLabel,
  FormMessage,
} from "@/components/ui/form"
import { Input } from "@/components/ui/input"

const formSchema = z.object({
  username: z.string().min(2, "Username must be at least 2 characters"),
  email: z.string().email("Invalid email address"),
})

type FormValues = z.infer<typeof formSchema>

export function ProfileForm() {
  const form = useForm<FormValues>({
    resolver: zodResolver(formSchema),
    defaultValues: {
      username: "",
      email: "",
    },
  })

  function onSubmit(values: FormValues) {
    console.log(values)
  }

  return (
    <Form {...form}>
      <form onSubmit={form.handleSubmit(onSubmit)} className="space-y-6">
        <FormField
          control={form.control}
          name="username"
          render={({ field }) => (
            <FormItem>
              <FormLabel>Username</FormLabel>
              <FormControl>
                <Input placeholder="johndoe" {...field} />
              </FormControl>
              <FormDescription>
                Your public display name.
              </FormDescription>
              <FormMessage />
            </FormItem>
          )}
        />

        <FormField
          control={form.control}
          name="email"
          render={({ field }) => (
            <FormItem>
              <FormLabel>Email</FormLabel>
              <FormControl>
                <Input type="email" placeholder="john@example.com" {...field} />
              </FormControl>
              <FormMessage />
            </FormItem>
          )}
        />

        <Button type="submit">Submit</Button>
      </form>
    </Form>
  )
}

With Server Actions

'use client'

import { useActionState } from 'react'
import { createUser } from './actions'
import { Button } from "@/components/ui/button"
import { Input } from "@/components/ui/input"
import { Label } from "@/components/ui/label"

export function SignupForm() {
  const [state, formAction, isPending] = useActionState(createUser, {
    error: null
  })

  return (
    <form action={formAction} className="space-y-4">
      <div className="space-y-2">
        <Label htmlFor="email">Email</Label>
        <Input
          id="email"
          name="email"
          type="email"
          disabled={isPending}
        />
      </div>

      <div className="space-y-2">
        <Label htmlFor="password">Password</Label>
        <Input
          id="password"
          name="password"
          type="password"
          disabled={isPending}
        />
      </div>

      {state.error && (
        <p className="text-sm text-destructive">{state.error}</p>
      )}

      <Button type="submit" disabled={isPending}>
        {isPending ? 'Creating...' : 'Create Account'}
      </Button>
    </form>
  )
}

Dark Mode

Theme Provider Setup

// components/theme-provider.tsx
'use client'

import * as React from 'react'
import { ThemeProvider as NextThemesProvider } from 'next-themes'

export function ThemeProvider({
  children,
  ...props
}: React.ComponentProps<typeof NextThemesProvider>) {
  return <NextThemesProvider {...props}>{children}</NextThemesProvider>
}

// app/layout.tsx
import { ThemeProvider } from "@/components/theme-provider"

export default function RootLayout({ children }) {
  return (
    <html lang="en" suppressHydrationWarning>
      <body>
        <ThemeProvider
          attribute="class"
          defaultTheme="system"
          enableSystem
          disableTransitionOnChange
        >
          {children}
        </ThemeProvider>
      </body>
    </html>
  )
}

Theme Toggle

'use client'

import { useTheme } from 'next-themes'
import { Button } from "@/components/ui/button"
import { Moon, Sun } from "lucide-react"

export function ThemeToggle() {
  const { theme, setTheme } = useTheme()

  return (
    <Button
      variant="ghost"
      size="icon"
      onClick={() => setTheme(theme === 'dark' ? 'light' : 'dark')}
    >
      <Sun className="h-5 w-5 rotate-0 scale-100 transition-all dark:-rotate-90 dark:scale-0" />
      <Moon className="absolute h-5 w-5 rotate-90 scale-0 transition-all dark:rotate-0 dark:scale-100" />
      <span className="sr-only">Toggle theme</span>
    </Button>
  )
}

Toast Notifications (Sonner)

// app/layout.tsx
import { Toaster } from "@/components/ui/sonner"

export default function RootLayout({ children }) {
  return (
    <html>
      <body>
        {children}
        <Toaster />
      </body>
    </html>
  )
}

// In components
import { toast } from "sonner"

function MyComponent() {
  return (
    <Button
      onClick={() => {
        toast.success("Success!", {
          description: "Your changes have been saved."
        })
      }}
    >
      Save
    </Button>
  )
}

// Other toast types
toast("Default toast")
toast.success("Success message")
toast.error("Error message")
toast.warning("Warning message")
toast.info("Info message")
toast.loading("Loading...")

// With action
toast("Event created", {
  action: {
    label: "Undo",
    onClick: () => console.log("Undo")
  }
})

// Promise-based
toast.promise(saveData(), {
  loading: "Saving...",
  success: "Saved!",
  error: "Error saving"
})

Common Patterns

Responsive Sheet/Dialog

'use client'

import { useMediaQuery } from "@/hooks/use-media-query"
import {
  Dialog,
  DialogContent,
  DialogHeader,
  DialogTitle,
} from "@/components/ui/dialog"
import {
  Sheet,
  SheetContent,
  SheetHeader,
  SheetTitle,
} from "@/components/ui/sheet"

interface ResponsiveModalProps {
  open: boolean
  onOpenChange: (open: boolean) => void
  title: string
  children: React.ReactNode
}

export function ResponsiveModal({
  open,
  onOpenChange,
  title,
  children
}: ResponsiveModalProps) {
  const isDesktop = useMediaQuery("(min-width: 768px)")

  if (isDesktop) {
    return (
      <Dialog open={open} onOpenChange={onOpenChange}>
        <DialogContent>
          <DialogHeader>
            <DialogTitle>{title}</DialogTitle>
          </DialogHeader>
          {children}
        </DialogContent>
      </Dialog>
    )
  }

  return (
    <Sheet open={open} onOpenChange={onOpenChange}>
      <SheetContent side="bottom">
        <SheetHeader>
          <SheetTitle>{title}</SheetTitle>
        </SheetHeader>
        {children}
      </SheetContent>
    </Sheet>
  )
}

Loading Button

import { Loader2 } from "lucide-react"
import { Button } from "@/components/ui/button"

interface LoadingButtonProps extends React.ComponentProps<typeof Button> {
  loading?: boolean
}

export function LoadingButton({
  children,
  loading,
  disabled,
  ...props
}: LoadingButtonProps) {
  return (
    <Button disabled={loading || disabled} {...props}>
      {loading && <Loader2 className="mr-2 h-4 w-4 animate-spin" />}
      {children}
    </Button>
  )
}

Additional Resources

For detailed patterns, see reference files:

• references/components.md - Full component catalog
• references/theming.md - Theme customization