액티비티 화면전환

Manifest

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.activitychange">
 
    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
 
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity android:name=".SubActivity"></activity>
    </application>
 
</manifest>

Main

package com.example.activitychange;
 
import androidx.appcompat.app.AppCompatActivity;
 
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
 
public class MainActivity extends AppCompatActivity {
 
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
 
        final EditText nameText = (EditText)findViewById(R.id.nameText);
        Button nameButton = (Button)findViewById(R.id.nameButton);
 
        nameButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                String name = nameText.getText().toString();
                Intent intent = new Intent(getApplicationContext(), SubActivity.class);
 
                intent.putExtra("nameText",name);
                startActivity(intent);
            }
        });
    }
}
 

SubActivity

package com.example.activitychange;
 
import android.content.Intent;
import android.os.Bundle;
import android.widget.TextView;
 
import androidx.appcompat.app.AppCompatActivity;
 
public class SubActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle bundle){
        super.onCreate(bundle);
        setContentView(R.layout.activity_sub);
 
        TextView nameText = (TextView)findViewById(R.id.nameText);
        Intent intent = getIntent();
 
        nameText.setText(intent.getStringExtra("nameText").toString());
    }
}