Android編程之仿iPhone滾輪控件

網上看到有人寫了一個滾動組件，這個不錯，你們能夠看看

可是，我我的以爲這裏有一處不是很好，你們能夠試試：不循環的狀況下，若是就是最後一個選項，你把它移到最上或者最下的位置，它回滾回到選擇條時，是直接跳過去的，而不是天然滑動過去的，這個須要改進一下！

　　這三張圖分別是使用滾動控件實現城市，隨機數和時間三個簡單的例子，固然，界面有點簡陋，下面咱們就以時間這個爲例，開始解析一下。

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_height="wrap_content"
    android:orientation="vertical"
    android:background="@drawable/layout_bg"
    android:layout_width="fill_parent">
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="24dp"
        android:layout_gravity="center_horizontal"
        android:textSize="20sp"
        android:text="Please select the city" />
    <LinearLayout
        xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal"
        android:layout_width="fill_parent"
        android:paddingLeft="12dp"
        android:paddingRight="12dp"
        android:paddingTop="4dp"
        android:layout_marginTop="8dp"
        android:orientation="horizontal">
        <kankan.wheel.widget.WheelView
            android:id="@+id/country"
            android:layout_height="wrap_content"
            android:layout_width="wrap_content"
            android:layout_gravity="center_vertical"
            android:layout_weight="1" />
        <kankan.wheel.widget.WheelView
            android:id="@+id/city"
            android:layout_height="wrap_content"
            android:layout_width="wrap_content"
            android:layout_marginLeft="10dp"
            android:layout_weight="1.5" />
    </LinearLayout>
    <!-- Button android:layout_width="wrap_content" android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal" android:layout_marginTop="18dp"
        android:textSize="18sp" android:text=" Next > "/ -->
</LinearLayout>

package kankan.wheel.demo;

import kankan.wheel.R;
import kankan.wheel.widget.ArrayWheelAdapter;
import kankan.wheel.widget.OnWheelChangedListener;
import kankan.wheel.widget.WheelView;

import android.app.Activity;
import android.os.Bundle;

public class CitiesActivity extends Activity {
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.cities_layout);

        WheelView country = (WheelView) findViewById(R.id.country);
        String countries[] = new String[] {"USA", "Canada", "Ukraine", "France"};
        country.setVisibleItems(3);
        country.setAdapter(new ArrayWheelAdapter<String>(countries));

        final String cities[][] = new String[][] {
                new String[] {"New York", "Washington", "Chicago", "Atlanta", "Orlando"},
                new String[] {"Ottawa", "Vancouver", "Toronto", "Windsor", "Montreal"},
                new String[] {"Kiev", "Dnipro", "Lviv", "Kharkiv"},
                new String[] {"Paris", "Bordeaux"},
                };

        final WheelView city = (WheelView) findViewById(R.id.city);
        city.setVisibleItems(5);

        country.addChangingListener(new OnWheelChangedListener() {
            public void onChanged(WheelView wheel, int oldValue, int newValue) {
                city.setAdapter(new ArrayWheelAdapter<String>(cities[newValue]));
                city.setCurrentItem(cities[newValue].length / 2);
            }
        });

        country.setCurrentItem(2);
    }
}