android LinearLayout java단에서 만들기

---- SampleLayoutCodeActivity.java
package com.example.administrator.myapplication_view;

import android.app.Activity;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.widget.Button;
import android.widget.LinearLayout;

public class SampleLayoutCodeActivity extends Activity {

    @Override    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        LinearLayout mainLayout = new LinearLayout(this);
        mainLayout.setOrientation(LinearLayout.VERTICAL);  // new 연산자로 LinearLayout을 만들고 방향 설정

        Button button01 = new Button(this); // Button 생성        button01.setText("Button 01");

        LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT); // new 연산자로 레이아웃 안에 추가될 버튼에 대한 설정에 대한 파라메터        button01.setLayoutParams(params);
        mainLayout.addView(button01);

        setContentView(mainLayout);
    }
}
-------- AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android"    package="com.example.administrator.myapplication_view">

    <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=".SampleLayoutCodeActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>