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build.gradle.kts (Module: app)

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공식 문서에 오류가 있음. enabled가 아니라 enable을 써야 함.

plugins {
    id("com.android.application")
    id("org.jetbrains.kotlin.android")
}

android {
    namespace = "com.example.w01thefirst"
    compileSdk = 33

    defaultConfig {
        applicationId = "com.example.w01thefirst"
        minSdk = 24
        targetSdk = 33
        versionCode = 1
        versionName = "1.0"

        testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
    }

    buildTypes {
        release {
            isMinifyEnabled = false
            proguardFiles(
                getDefaultProguardFile("proguard-android-optimize.txt"),
                "proguard-rules.pro"
            )
        }
    }
    compileOptions {
        sourceCompatibility = JavaVersion.VERSION_1_8
        targetCompatibility = JavaVersion.VERSION_1_8
    }
    kotlinOptions {
        jvmTarget = "1.8"
    }

    **viewBinding {
        enable = true
    }**
}

dependencies {

    implementation("androidx.core:core-ktx:1.9.0")
    implementation("androidx.appcompat:appcompat:1.6.1")
    implementation("com.google.android.material:material:1.8.0")
    implementation("androidx.constraintlayout:constraintlayout:2.1.4")
    testImplementation("junit:junit:4.13.2")
    androidTestImplementation("androidx.test.ext:junit:1.1.5")
    androidTestImplementation("androidx.test.espresso:espresso-core:3.5.1")
}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="<http://schemas.android.com/apk/res/android>"
    xmlns:app="<http://schemas.android.com/apk/res-auto>"
    xmlns:tools="<http://schemas.android.com/tools>"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".MainActivity">

    <TextView
        android:id="@+id/txtCount"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="0"
        android:textSize="50sp"
        android:layout_gravity="center"
        />
    <Button
        android:id="@+id/btnAdd"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="눌러 주세요"
        />

</LinearLayout>

MainActivity.kt

<aside> 🍰 레이아웃 파일 이름은 activity_main.xml로 snake case를 사용한다. 클래스 이름은 파일 이름을 Pascal case로 바꾸고 뒤에 Binding을 붙인 ActivityMainBinding 이다.

</aside>

package com.example.w01thefirst

import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import com.example.w01thefirst.databinding.ActivityMainBinding

class MainActivity : AppCompatActivity() {
    private lateinit var main: ActivityMainBinding
    private var count = 0;
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        //setContentView(R.layout.activity_main)
        main = ActivityMainBinding.inflate(layoutInflater)
        setContentView(main.root)

        main.btnAdd.setOnClickListener {
            main.txtCount.text = "${++count}"
        }
    }
}

실행 화면

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LinearLayout

match_parent 및 wrap_content