Intents: Screens और Apps खोलें

// MainActivity.kt – open the detail screen
binding.btnOpen.setOnClickListener {
    val intent = Intent(this, DetailActivity::class.java)
    startActivity(intent)
}

// DetailActivity.kt
class DetailActivity : AppCompatActivity() {
    private lateinit var binding: ActivityDetailBinding
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        binding = ActivityDetailBinding.inflate(layoutInflater)
        setContentView(binding.root)
        binding.btnClose.setOnClickListener { finish() }     // back to MainActivity
    }
}

<!-- AndroidManifest.xml (Android Studio adds this when you use New → Activity) -->
<application>
    <activity
        android:name=".MainActivity"
        android:exported="true">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>

    <activity
        android:name=".DetailActivity"
        android:exported="false"
        android:parentActivityName=".MainActivity" />
</application>

// 1. Open a website
startActivity(Intent(Intent.ACTION_VIEW, Uri.parse("https://codingeasily.in")))

// 2. Dial a phone number (no permission needed)
startActivity(Intent(Intent.ACTION_DIAL, Uri.parse("tel:+919000000000")))

// 3. Share text (WhatsApp, Telegram, Gmail … user chooses)
val send = Intent(Intent.ACTION_SEND).apply {
    type = "text/plain"
    putExtra(Intent.EXTRA_TEXT, "Learn Android free: https://codingeasily.in/tutorial/android/")
}
startActivity(Intent.createChooser(send, "Share via"))

// 4. Send an email
val email = Intent(Intent.ACTION_SENDTO).apply {
    data = Uri.parse("mailto:")
    putExtra(Intent.EXTRA_EMAIL, arrayOf("help@codingeasily.in"))
    putExtra(Intent.EXTRA_SUBJECT, "Doubt in lesson 20")
}
startActivity(email)

// 5. Open a place in Google Maps
startActivity(Intent(Intent.ACTION_VIEW, Uri.parse("geo:0,0?q=Aligarh Muslim University")))

// 6. WhatsApp chat with a message
startActivity(Intent(Intent.ACTION_VIEW, Uri.parse("https://wa.me/919000000000?text=Hi")))

// 7. App settings page (e.g. after a permission was denied)
startActivity(Intent(Settings.ACTION_APPLICATION_DETAILS_SETTINGS, Uri.fromParts("package", packageName, null)))

fun Context.openSafely(intent: Intent) {
    try {
        startActivity(intent)
    } catch (e: ActivityNotFoundException) {
        Toast.makeText(this, "No app found to open this", Toast.LENGTH_SHORT).show()
    }
}

// usage
openSafely(Intent(Intent.ACTION_VIEW, Uri.parse("geo:0,0?q=Taj Mahal")))

// After login: open Home and remove Login from the back stack
val intent = Intent(this, HomeActivity::class.java).apply {
    flags = Intent.FLAG_ACTIVITY_NEW_TASK or Intent.FLAG_ACTIVITY_CLEAR_TASK
}
startActivity(intent)
// or simply: startActivity(...); finish()