android -以编程方式创建一个微调控件或不创建

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".MainActivity">

    <NumberPicker
        android:id="@+id/numberPicker"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:minValue="0"
        android:maxValue="100"
        android:value="50"
        android:layout_gravity="center_horizontal" />

</LinearLayout>

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.widget.NumberPicker;

public class MainActivity extends AppCompatActivity {

    private NumberPicker numberPicker;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        numberPicker = findViewById(R.id.numberPicker);

        int value = numberPicker.getValue();
        // 处理微调控件的值
    }
}