android開発 Fragment利用

2022 Oct. 23.

出典
[Android & Kotlin] Fragment をActivityに追加
[Android] Fragment コードで記述する

build.gradle (Module: app)

"implementation 'androidx.fragment:fragment-ktx:1.5.3'"を記述する

plugins {
    id 'com.android.application'
    id 'org.jetbrains.kotlin.android'
}

android {
    compileSdk 33

    defaultConfig {
        applicationId "net.sytes.rokkosan.myfragment"
        minSdk 30
        targetSdk 33
        versionCode 1
        versionName "1.0"

        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
    }

    buildTypes {
        release {
            minifyEnabled 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'
    }
}

dependencies {

    implementation 'androidx.core:core-ktx:1.9.0'
    implementation 'androidx.appcompat:appcompat:1.5.1'
    implementation 'com.google.android.material:material:1.7.0'
    implementation 'androidx.constraintlayout:constraintlayout:2.1.4'
    testImplementation 'junit:junit:4.13.2'
    androidTestImplementation 'androidx.test.ext:junit:1.1.3'
    androidTestImplementation 'androidx.test.espresso:espresso-core:3.4.0'
    implementation 'androidx.fragment:fragment-ktx:1.5.3'
}

MainActivity.kt

/*
 2022 Oct. 23.
 This application is copy of https://akira-watson.com/android/kotlin/fragment-programmatically.html.
 But modified with https://akira-watson.com/android/fragment-code.html.
 */

package net.sytes.rokkosan.myfragment

import android.os.Bundle
import androidx.appcompat.app.AppCompatActivity
import androidx.fragment.app.FragmentManager
import androidx.fragment.app.FragmentTransaction

class MainActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        if (savedInstanceState == null) {
            // FragmentManagerのインスタンス生成
            val fragmentManager: FragmentManager = supportFragmentManager

            // FragmentTransactionのインスタンスを取得
            val fragmentTransaction: FragmentTransaction = fragmentManager.beginTransaction()

            // インスタンスに対して張り付け方を指定する
            fragmentTransaction.replace(R.id.fragment, SampleFragment())

            // 張り付けを実行
            fragmentTransaction.commit()
        }
    }
}

SampleFragment.kt

package net.sytes.rokkosan.myfragment

import android.os.Bundle
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import androidx.fragment.app.Fragment

class SampleFragment: Fragment() {
    override fun onCreateView(
        inflater: LayoutInflater,
        container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View {
        // Inflate the layout for this fragment
        return inflater.inflate(R.layout.fragment_main, container, false)
    }
}

activity_main.xml

<?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:layout_width="match_parent"
    android:layout_height="match_parent"
    android:padding="20dp"
    android:background="#def"
    tools:context=".MainActivity">

    <androidx.fragment.app.FragmentContainerView
        android:id="@+id/fragment"
        android:layout_width="wrap_content"
        android:layout_height="300dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.5" />

</androidx.constraintlayout.widget.ConstraintLayout>

fragment_main.xml

<?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"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#bcd"
    android:orientation="vertical"
    android:gravity="center"
    >

    <TextView
        android:text="@string/hello_fragment"
        android:layout_width="wrap_content"
        android:textSize="40sp"
        android:textColor="#03f"
        android:layout_height="wrap_content"

        android:id="@+id/textView"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        />

</androidx.constraintlayout.widget.ConstraintLayout>

strings.xml

<resources>
    <string name="app_name">MyFragment</string>
    <string name="hello_fragment">Hello Fragment</string>
</resources>