React Native: สร้างแอปมือถืออย่างสมบูรณ์ในปี 2026

# setup.sh
# Node.js installation (LTS version recommended)
# Check installed version
node --version  # >= 18.x required
npm --version   # >= 9.x required

# Install Expo CLI tool globally
npm install -g expo-cli

# Create a new project with Expo
npx create-expo-app@latest MyApp --template blank-typescript

# Navigate to the project
cd MyApp

# Start the development server
npx expo start

# structure.sh
# Generated project structure
MyApp/
├── App.tsx              # Application entry point
├── app.json             # Expo configuration
├── package.json         # Dependencies
├── tsconfig.json        # TypeScript configuration
├── babel.config.js      # Babel configuration
└── assets/              # Images and resources
    ├── icon.png
    └── splash.png

import React from 'react';
import {
  View,
  Text,
  StyleSheet,
  SafeAreaView,
  StatusBar
} from 'react-native';

// Main application component
export default function App() {
  return (
    // SafeAreaView prevents overlap with status bar
    <SafeAreaView style={styles.container}>
      {/* StatusBar configures system bar appearance */}
      <StatusBar barStyle="dark-content" />

      {/* View is the equivalent of div */}
      <View style={styles.header}>
        {/* Text is required to display text */}
        <Text style={styles.title}>Welcome to MyApp</Text>
        <Text style={styles.subtitle}>
          A React Native application
        </Text>
      </View>
    </SafeAreaView>
  );
}

// StyleSheet.create optimizes styles for native
const styles = StyleSheet.create({
  container: {
    flex: 1,                    // Takes all available space
    backgroundColor: '#ffffff',
  },
  header: {
    padding: 20,
    alignItems: 'center',       // Centers horizontally
    justifyContent: 'center',   // Centers vertically
  },
  title: {
    fontSize: 24,
    fontWeight: 'bold',
    color: '#1a1a1a',
    marginBottom: 8,
  },
  subtitle: {
    fontSize: 16,
    color: '#666666',
  },
});

import React, { useState } from 'react';
import {
  TouchableOpacity,
  TouchableHighlight,
  Pressable,
  Text,
  StyleSheet,
  View,
} from 'react-native';

// Button component with different interaction styles
export function InteractiveButton() {
  const [count, setCount] = useState(0);

  return (
    <View style={styles.container}>
      {/* TouchableOpacity reduces opacity on touch */}
      <TouchableOpacity
        style={styles.button}
        activeOpacity={0.7}
        onPress={() => setCount(c => c + 1)}
      >
        <Text style={styles.buttonText}>
          Counter: {count}
        </Text>
      </TouchableOpacity>

      {/* Pressable offers more control over states */}
      <Pressable
        style={({ pressed }) => [
          styles.button,
          styles.pressableButton,
          pressed && styles.buttonPressed,
        ]}
        onPress={() => console.log('Pressed!')}
        onLongPress={() => console.log('Long press!')}
      >
        {({ pressed }) => (
          <Text style={styles.buttonText}>
            {pressed ? 'Pressed!' : 'Press here'}
          </Text>
        )}
      </Pressable>
    </View>
  );
}

const styles = StyleSheet.create({
  container: {
    gap: 16,
    padding: 20,
  },
  button: {
    backgroundColor: '#007AFF',
    paddingVertical: 14,
    paddingHorizontal: 28,
    borderRadius: 10,
    alignItems: 'center',
  },
  pressableButton: {
    backgroundColor: '#34C759',
  },
  buttonPressed: {
    backgroundColor: '#2DA44E',
    transform: [{ scale: 0.98 }],
  },
  buttonText: {
    color: '#ffffff',
    fontSize: 16,
    fontWeight: '600',
  },
});

# install-navigation.sh
# Installing navigation dependencies
npx expo install @react-navigation/native
npx expo install @react-navigation/native-stack
npx expo install react-native-screens react-native-safe-area-context

import React from 'react';
import { NavigationContainer } from '@react-navigation/native';
import { createNativeStackNavigator } from '@react-navigation/native-stack';

// Screen imports
import { HomeScreen } from './screens/HomeScreen';
import { DetailScreen } from './screens/DetailScreen';
import { ProfileScreen } from './screens/ProfileScreen';

// Type definition for TypeScript navigation
export type RootStackParamList = {
  Home: undefined;                    // No parameters
  Detail: { itemId: number; title: string };  // Required parameters
  Profile: { userId?: string };       // Optional parameter
};

// Creating typed navigator
const Stack = createNativeStackNavigator<RootStackParamList>();

export default function App() {
  return (
    // NavigationContainer manages navigation state
    <NavigationContainer>
      <Stack.Navigator
        initialRouteName="Home"
        screenOptions={{
          headerStyle: { backgroundColor: '#007AFF' },
          headerTintColor: '#ffffff',
          headerTitleStyle: { fontWeight: 'bold' },
        }}
      >
        <Stack.Screen
          name="Home"
          component={HomeScreen}
          options={{ title: 'Home' }}
        />
        <Stack.Screen
          name="Detail"
          component={DetailScreen}
          options={({ route }) => ({
            title: route.params.title
          })}
        />
        <Stack.Screen
          name="Profile"
          component={ProfileScreen}
        />
      </Stack.Navigator>
    </NavigationContainer>
  );
}

import React from 'react';
import { View, Text, FlatList, TouchableOpacity, StyleSheet } from 'react-native';
import { NativeStackScreenProps } from '@react-navigation/native-stack';
import { RootStackParamList } from '../App';

// Typing navigation props
type Props = NativeStackScreenProps<RootStackParamList, 'Home'>;

// Sample data
const ITEMS = [
  { id: 1, title: 'First item' },
  { id: 2, title: 'Second item' },
  { id: 3, title: 'Third item' },
];

export function HomeScreen({ navigation }: Props) {
  return (
    <View style={styles.container}>
      {/* FlatList for performant lists */}
      <FlatList
        data={ITEMS}
        keyExtractor={(item) => item.id.toString()}
        renderItem={({ item }) => (
          <TouchableOpacity
            style={styles.item}
            onPress={() => {
              // Navigation with typed parameters
              navigation.navigate('Detail', {
                itemId: item.id,
                title: item.title,
              });
            }}
          >
            <Text style={styles.itemText}>{item.title}</Text>
          </TouchableOpacity>
        )}
        ItemSeparatorComponent={() => <View style={styles.separator} />}
      />
    </View>
  );
}

const styles = StyleSheet.create({
  container: {
    flex: 1,
    backgroundColor: '#f5f5f5',
  },
  item: {
    backgroundColor: '#ffffff',
    padding: 20,
  },
  itemText: {
    fontSize: 16,
    color: '#1a1a1a',
  },
  separator: {
    height: 1,
    backgroundColor: '#e0e0e0',
  },
});

import React, { createContext, useContext, useState, useCallback } from 'react';

// Types for authentication
interface User {
  id: string;
  email: string;
  name: string;
}

interface AuthContextType {
  user: User | null;
  isLoading: boolean;
  signIn: (email: string, password: string) => Promise<void>;
  signOut: () => void;
}

// Creating context with default value
const AuthContext = createContext<AuthContextType | undefined>(undefined);

// Provider that wraps the application
export function AuthProvider({ children }: { children: React.ReactNode }) {
  const [user, setUser] = useState<User | null>(null);
  const [isLoading, setIsLoading] = useState(false);

  // Sign in function
  const signIn = useCallback(async (email: string, password: string) => {
    setIsLoading(true);
    try {
      // Simulated API call
      const response = await fetch('https://api.example.com/login', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ email, password }),
      });
      const data = await response.json();
      setUser(data.user);
    } catch (error) {
      console.error('Login error:', error);
      throw error;
    } finally {
      setIsLoading(false);
    }
  }, []);

  // Sign out function
  const signOut = useCallback(() => {
    setUser(null);
  }, []);

  return (
    <AuthContext.Provider value={{ user, isLoading, signIn, signOut }}>
      {children}
    </AuthContext.Provider>
  );
}

// Custom hook to use the context
export function useAuth() {
  const context = useContext(AuthContext);
  if (context === undefined) {
    throw new Error('useAuth must be used within an AuthProvider');
  }
  return context;
}

import React, { useState } from 'react';
import {
  View,
  Text,
  TextInput,
  TouchableOpacity,
  StyleSheet,
  ActivityIndicator,
  Alert,
} from 'react-native';
import { useAuth } from '../context/AuthContext';

export function LoginScreen() {
  const [email, setEmail] = useState('');
  const [password, setPassword] = useState('');
  const { signIn, isLoading } = useAuth();

  // Form submission handler
  const handleSubmit = async () => {
    if (!email || !password) {
      Alert.alert('Error', 'Please fill in all fields');
      return;
    }

    try {
      await signIn(email, password);
    } catch (error) {
      Alert.alert('Error', 'Invalid credentials');
    }
  };

  return (
    <View style={styles.container}>
      <Text style={styles.title}>Login</Text>

      <TextInput
        style={styles.input}
        placeholder="Email"
        value={email}
        onChangeText={setEmail}
        keyboardType="email-address"
        autoCapitalize="none"
        autoComplete="email"
      />

      <TextInput
        style={styles.input}
        placeholder="Password"
        value={password}
        onChangeText={setPassword}
        secureTextEntry
        autoComplete="password"
      />

      <TouchableOpacity
        style={[styles.button, isLoading && styles.buttonDisabled]}
        onPress={handleSubmit}
        disabled={isLoading}
      >
        {isLoading ? (
          <ActivityIndicator color="#ffffff" />
        ) : (
          <Text style={styles.buttonText}>Sign In</Text>
        )}
      </TouchableOpacity>
    </View>
  );
}

const styles = StyleSheet.create({
  container: {
    flex: 1,
    padding: 20,
    justifyContent: 'center',
    backgroundColor: '#ffffff',
  },
  title: {
    fontSize: 28,
    fontWeight: 'bold',
    marginBottom: 32,
    textAlign: 'center',
  },
  input: {
    borderWidth: 1,
    borderColor: '#e0e0e0',
    borderRadius: 10,
    padding: 16,
    marginBottom: 16,
    fontSize: 16,
    backgroundColor: '#f9f9f9',
  },
  button: {
    backgroundColor: '#007AFF',
    padding: 16,
    borderRadius: 10,
    alignItems: 'center',
    marginTop: 8,
  },
  buttonDisabled: {
    backgroundColor: '#99c9ff',
  },
  buttonText: {
    color: '#ffffff',
    fontSize: 18,
    fontWeight: '600',
  },
});

// Base API configuration
const API_BASE_URL = 'https://api.example.com';

// Type for API errors
interface ApiError {
  message: string;
  code: string;
  status: number;
}

// Utility function for requests
async function request<T>(
  endpoint: string,
  options: RequestInit = {}
): Promise<T> {
  const url = `${API_BASE_URL}${endpoint}`;

  const config: RequestInit = {
    ...options,
    headers: {
      'Content-Type': 'application/json',
      ...options.headers,
    },
  };

  try {
    const response = await fetch(url, config);

    if (!response.ok) {
      const error: ApiError = await response.json();
      throw new Error(error.message || 'An error occurred');
    }

    return response.json();
  } catch (error) {
    // Network error handling
    if (error instanceof TypeError) {
      throw new Error('Network connection issue');
    }
    throw error;
  }
}

// Types for entities
interface Product {
  id: string;
  name: string;
  price: number;
  description: string;
  imageUrl: string;
}

// Products service
export const productApi = {
  // Get all products
  getAll: () => request<Product[]>('/products'),

  // Get product by ID
  getById: (id: string) => request<Product>(`/products/${id}`),

  // Create a product
  create: (data: Omit<Product, 'id'>) =>
    request<Product>('/products', {
      method: 'POST',
      body: JSON.stringify(data),
    }),

  // Update a product
  update: (id: string, data: Partial<Product>) =>
    request<Product>(`/products/${id}`, {
      method: 'PATCH',
      body: JSON.stringify(data),
    }),
};

import { useState, useEffect, useCallback } from 'react';
import { productApi } from '../services/api';

interface Product {
  id: string;
  name: string;
  price: number;
  description: string;
  imageUrl: string;
}

// Custom hook for product management
export function useProducts() {
  const [products, setProducts] = useState<Product[]>([]);
  const [isLoading, setIsLoading] = useState(true);
  const [error, setError] = useState<string | null>(null);

  // Initial products loading
  const fetchProducts = useCallback(async () => {
    setIsLoading(true);
    setError(null);

    try {
      const data = await productApi.getAll();
      setProducts(data);
    } catch (err) {
      setError(err instanceof Error ? err.message : 'Unknown error');
    } finally {
      setIsLoading(false);
    }
  }, []);

  // Refresh (pull-to-refresh)
  const refresh = useCallback(async () => {
    await fetchProducts();
  }, [fetchProducts]);

  // Load on mount
  useEffect(() => {
    fetchProducts();
  }, [fetchProducts]);

  return {
    products,
    isLoading,
    error,
    refresh,
  };
}

import React from 'react';
import {
  View,
  Text,
  FlatList,
  Image,
  StyleSheet,
  RefreshControl,
  ActivityIndicator,
} from 'react-native';
import { useProducts } from '../hooks/useProducts';

export function ProductListScreen() {
  const { products, isLoading, error, refresh } = useProducts();

  // Display during initial loading
  if (isLoading && products.length === 0) {
    return (
      <View style={styles.centered}>
        <ActivityIndicator size="large" color="#007AFF" />
        <Text style={styles.loadingText}>Loading...</Text>
      </View>
    );
  }

  // Display on error
  if (error) {
    return (
      <View style={styles.centered}>
        <Text style={styles.errorText}>{error}</Text>
      </View>
    );
  }

  return (
    <FlatList
      data={products}
      keyExtractor={(item) => item.id}
      contentContainerStyle={styles.list}
      // Pull-to-refresh
      refreshControl={
        <RefreshControl
          refreshing={isLoading}
          onRefresh={refresh}
          tintColor="#007AFF"
        />
      }
      renderItem={({ item }) => (
        <View style={styles.card}>
          <Image
            source={{ uri: item.imageUrl }}
            style={styles.image}
            resizeMode="cover"
          />
          <View style={styles.cardContent}>
            <Text style={styles.productName}>{item.name}</Text>
            <Text style={styles.productPrice}>
              ${item.price.toFixed(2)}
            </Text>
          </View>
        </View>
      )}
    />
  );
}

const styles = StyleSheet.create({
  centered: {
    flex: 1,
    justifyContent: 'center',
    alignItems: 'center',
    padding: 20,
  },
  loadingText: {
    marginTop: 12,
    fontSize: 16,
    color: '#666666',
  },
  errorText: {
    fontSize: 16,
    color: '#FF3B30',
    textAlign: 'center',
  },
  list: {
    padding: 16,
  },
  card: {
    backgroundColor: '#ffffff',
    borderRadius: 12,
    marginBottom: 16,
    shadowColor: '#000',
    shadowOffset: { width: 0, height: 2 },
    shadowOpacity: 0.1,
    shadowRadius: 4,
    elevation: 3,
  },
  image: {
    width: '100%',
    height: 200,
    borderTopLeftRadius: 12,
    borderTopRightRadius: 12,
  },
  cardContent: {
    padding: 16,
  },
  productName: {
    fontSize: 18,
    fontWeight: '600',
    color: '#1a1a1a',
    marginBottom: 4,
  },
  productPrice: {
    fontSize: 16,
    color: '#007AFF',
    fontWeight: '500',
  },
});

import AsyncStorage from '@react-native-async-storage/async-storage';

// Required installation: npx expo install @react-native-async-storage/async-storage

// Centralized storage keys
const STORAGE_KEYS = {
  USER_TOKEN: '@app/user_token',
  USER_PREFERENCES: '@app/user_preferences',
  ONBOARDING_COMPLETE: '@app/onboarding_complete',
} as const;

// Types for user preferences
interface UserPreferences {
  theme: 'light' | 'dark' | 'system';
  notifications: boolean;
  language: string;
}

// Typed storage service
export const storage = {
  // Authentication token
  async getToken(): Promise<string | null> {
    return AsyncStorage.getItem(STORAGE_KEYS.USER_TOKEN);
  },

  async setToken(token: string): Promise<void> {
    await AsyncStorage.setItem(STORAGE_KEYS.USER_TOKEN, token);
  },

  async removeToken(): Promise<void> {
    await AsyncStorage.removeItem(STORAGE_KEYS.USER_TOKEN);
  },

  // User preferences (JSON object)
  async getPreferences(): Promise<UserPreferences | null> {
    const data = await AsyncStorage.getItem(STORAGE_KEYS.USER_PREFERENCES);
    return data ? JSON.parse(data) : null;
  },

  async setPreferences(prefs: UserPreferences): Promise<void> {
    await AsyncStorage.setItem(
      STORAGE_KEYS.USER_PREFERENCES,
      JSON.stringify(prefs)
    );
  },

  // Onboarding
  async isOnboardingComplete(): Promise<boolean> {
    const value = await AsyncStorage.getItem(STORAGE_KEYS.ONBOARDING_COMPLETE);
    return value === 'true';
  },

  async setOnboardingComplete(): Promise<void> {
    await AsyncStorage.setItem(STORAGE_KEYS.ONBOARDING_COMPLETE, 'true');
  },

  // Complete cleanup
  async clearAll(): Promise<void> {
    const keys = Object.values(STORAGE_KEYS);
    await AsyncStorage.multiRemove(keys);
  },
};

import { Dimensions, PixelRatio, Platform } from 'react-native';

const { width: SCREEN_WIDTH, height: SCREEN_HEIGHT } = Dimensions.get('window');

// Reference dimensions (iPhone 14)
const guidelineBaseWidth = 390;
const guidelineBaseHeight = 844;

// Scaling functions
export const scale = (size: number) =>
  (SCREEN_WIDTH / guidelineBaseWidth) * size;

export const verticalScale = (size: number) =>
  (SCREEN_HEIGHT / guidelineBaseHeight) * size;

export const moderateScale = (size: number, factor = 0.5) =>
  size + (scale(size) - size) * factor;

// Light theme
export const lightTheme = {
  colors: {
    primary: '#007AFF',
    secondary: '#5856D6',
    success: '#34C759',
    warning: '#FF9500',
    error: '#FF3B30',
    background: '#FFFFFF',
    surface: '#F2F2F7',
    text: '#000000',
    textSecondary: '#8E8E93',
    border: '#E5E5EA',
  },
  spacing: {
    xs: scale(4),
    sm: scale(8),
    md: scale(16),
    lg: scale(24),
    xl: scale(32),
  },
  typography: {
    h1: {
      fontSize: moderateScale(32),
      fontWeight: 'bold' as const,
      lineHeight: moderateScale(40),
    },
    h2: {
      fontSize: moderateScale(24),
      fontWeight: 'bold' as const,
      lineHeight: moderateScale(32),
    },
    body: {
      fontSize: moderateScale(16),
      lineHeight: moderateScale(24),
    },
    caption: {
      fontSize: moderateScale(14),
      lineHeight: moderateScale(20),
    },
  },
  borderRadius: {
    sm: scale(4),
    md: scale(8),
    lg: scale(12),
    full: 9999,
  },
};

// Dark theme
export const darkTheme = {
  ...lightTheme,
  colors: {
    ...lightTheme.colors,
    background: '#000000',
    surface: '#1C1C1E',
    text: '#FFFFFF',
    textSecondary: '#8E8E93',
    border: '#38383A',
  },
};

export type Theme = typeof lightTheme;

import React, { createContext, useContext, useState, useEffect } from 'react';
import { useColorScheme } from 'react-native';
import { lightTheme, darkTheme, Theme } from '../theme';
import { storage } from '../services/storage';

interface ThemeContextType {
  theme: Theme;
  isDark: boolean;
  toggleTheme: () => void;
  setThemeMode: (mode: 'light' | 'dark' | 'system') => void;
}

const ThemeContext = createContext<ThemeContextType | undefined>(undefined);

export function ThemeProvider({ children }: { children: React.ReactNode }) {
  const systemColorScheme = useColorScheme();
  const [themeMode, setThemeMode] = useState<'light' | 'dark' | 'system'>('system');

  // Determine effective theme
  const isDark =
    themeMode === 'system'
      ? systemColorScheme === 'dark'
      : themeMode === 'dark';

  const theme = isDark ? darkTheme : lightTheme;

  // Load preferences on startup
  useEffect(() => {
    storage.getPreferences().then((prefs) => {
      if (prefs?.theme) {
        setThemeMode(prefs.theme);
      }
    });
  }, []);

  // Toggle between light and dark
  const toggleTheme = () => {
    const newMode = isDark ? 'light' : 'dark';
    setThemeMode(newMode);
    storage.getPreferences().then((prefs) => {
      storage.setPreferences({
        ...prefs,
        theme: newMode,
        notifications: prefs?.notifications ?? true,
        language: prefs?.language ?? 'en',
      });
    });
  };

  return (
    <ThemeContext.Provider value={{ theme, isDark, toggleTheme, setThemeMode }}>
      {children}
    </ThemeContext.Provider>
  );
}

export function useTheme() {
  const context = useContext(ThemeContext);
  if (!context) {
    throw new Error('useTheme must be used within a ThemeProvider');
  }
  return context;
}

{
  "expo": {
    "name": "MyApp",
    "slug": "my-app",
    "version": "1.0.0",
    "orientation": "portrait",
    "icon": "./assets/icon.png",
    "userInterfaceStyle": "automatic",
    "splash": {
      "image": "./assets/splash.png",
      "resizeMode": "contain",
      "backgroundColor": "#007AFF"
    },
    "ios": {
      "supportsTablet": true,
      "bundleIdentifier": "com.example.myapp",
      "buildNumber": "1"
    },
    "android": {
      "adaptiveIcon": {
        "foregroundImage": "./assets/adaptive-icon.png",
        "backgroundColor": "#007AFF"
      },
      "package": "com.example.myapp",
      "versionCode": 1
    },
    "plugins": [
      "expo-router"
    ]
  }
}

# build.sh
# EAS Build configuration (Expo Application Services)
npm install -g eas-cli

# Log in to Expo account
eas login

# Configure the project
eas build:configure

# Build for iOS (simulator)
eas build --platform ios --profile development

# Build for Android (test APK)
eas build --platform android --profile preview

# Production build
eas build --platform all --profile production

# Store submission
eas submit --platform ios
eas submit --platform android