[Android ]Progress Bar - Kotlin

build.gradle (Module)에서 viewBinding true 설정 

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프로그래스 바를 아래와 같이 배치를 해주고 

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 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:id="@+id/parent"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <LinearLayout
        android:id="@+id/progressLayout"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:gravity="center"
        android:orientation="vertical"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent">

        <ProgressBar
            android:id="@+id/progressBar"
            style="?android:attr/progressBarStyle"
            android:layout_width="match_parent"
            android:layout_height="wrap_content" />

        <TextView
            android:id="@+id/textView"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:gravity="center"
            android:text="Downloading..." />
    </LinearLayout>
</androidx.constraintlayout.widget.ConstraintLayout>

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MainActivity.kt

UI  작업은 MainTread에서 해주어야 하기 때문에 아래와 같이 코드를 작성 합니다.

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

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

        thread(start=true){         // 서브 스레드
            Thread.sleep(3000)

            runOnUiThread {     // 메인 스레드
                showProgress(false)
            }
        }
    }

    fun showProgress(show : Boolean){
        if(show) binding.progressLayout.visibility = View.VISIBLE
        else binding.progressLayout.visibility = View.GONE
    }
}

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