안드로이드 앱 개발 연습 - 1 | Basic Setting & Event

Basic Setting

build.gradle (:app)

android {
    buildFeatures {
        viewBinding true
    }
    ...
}

MainActivity.kt

class MainActivity : AppCompatActivity() {
    private val binding by lazy { ActivityMainBinding.inflate(layoutInflater) }

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(binding.root)
    }
}

---

Button Event

Basic Button

class MainActivity : AppCompatActivity() {
    private val binding by lazy { ActivityMainBinding.inflate(layoutInflater) }

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(binding.root)
        
        binding.button.setOnClickListener {
            binding.textBox.setText("Changed Text")
        }
    }
}

Radio Button

class MainActivity : AppCompatActivity() {
    private val binding by lazy { ActivityMainBinding.inflate(layoutInflater) }

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(binding.root)
        
        binding.radioGroup.setOnCheckedChangeListener { group, checkedId ->
            when (checkedId) {
                R.id.Btn1 -> Log.d("RadioButton", "Select Button1")
                R.id.Btn2 -> Log.d("RadioButton", "Select Button2")
                R.id.Btn3 -> Log.d("RadioButton", "Select Button3")
            }
        }
    }
}

Check Box

class MainActivity : AppCompatActivity() {
    private val binding by lazy { ActivityMainBinding.inflate(layoutInflater) }
    private val listener by lazy {
        CompoundButton.OnCheckedChangeListener { buttonView, isChecked ->
            when (buttonView.id) {
                R.id.checkBox1 -> Log.d("CheckBox", "${if (isChecked) "BOX1 ON" else "BOX1 OFF"}")
                R.id.checkBox2 -> Log.d("CheckBox", "${if (isChecked) "BOX2 ON" else "BOX2 OFF"}")
                R.id.checkBox3 -> Log.d("CheckBox", "${if (isChecked) "BOX3 ON" else "BOX3 OFF"}")
            }
        }
    }
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(binding.root)
        
        binding.checkBox1.setOnCheckedChangeListener(listener)
        binding.checkBox2.setOnCheckedChangeListener(listener)
        binding.checkBox3.setOnCheckedChangeListener(listener)
        }
    }
}

Switch

class MainActivity : AppCompatActivity() {
    private val binding by lazy { ActivityMainBinding.inflate(layoutInflater) }

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(binding.root)
       
        binding.switch1.setOnCheckedChangeListener { buttonView, isChecked -> Log.d("SWITCH", "${if (isChecked) "SWITCH1 ON" else "SWITCH1 OFF"}") }
        binding.switch2.setOnCheckedChangeListener { buttonView, isChecked -> Log.d("SWITCH", "${if (isChecked) "SWITCH2 ON" else "SWITCH2 OFF"}") }
        binding.switch3.setOnCheckedChangeListener { buttonView, isChecked -> Log.d("SWITCH", "${if (isChecked) "SWITCH3 ON" else "SWITCH3 OFF"}") }
    }
}

---

Widgets Event

SeekBar

class MainActivity : AppCompatActivity() {
    private val binding by lazy { ActivityMainBinding.inflate(layoutInflater) }

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(binding.root)
        
        binding.seekBar.setOnSeekBarChangeListener(object: SeekBar.OnSeekBarChangeListener {
            override fun onProgressChanged(seekBar: SeekBar?, progress: Int, fromUser: Boolean) {
                binding.seekBarValue.text = "$progress"
            }
            override fun onStartTrackingTouch(seekBar: SeekBar?) {}
            override fun onStopTrackingTouch(seekBar: SeekBar?) {}
        })
    }
}

---

Edit Text Event

class MainActivity : AppCompatActivity() {
    private val binding by lazy { ActivityMainBinding.inflate(layoutInflater) }

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(binding.root)

        binding.inputText.addTextChangedListener {
            Log.d("EditText", "Input: ${it.toString()}")
        }
    }
}