Android學習筆記 - 下拉式選單(Spinner)

1. 透過Spinner物件建立下拉式選單

2. MainActivity.java

package org.me.android_spinner;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Spinner;
import android.widget.Toast;

public class MainActivity extends Activity {
    @Override
    public void onCreate(Bundle icicle) {
        super.onCreate(icicle);
        setContentView(R.layout.main);
        Spinner spinner = (Spinner) findViewById(R.id.spinnner);
        //建立一個ArrayAdapter物件，並放置下拉選單的內容
        ArrayAdapter adapter = new ArrayAdapter(this,android.R.layout.simple_spinner_item,new String[]{"紅茶","奶茶","綠茶"});
        //設定下拉選單的樣式
        adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        spinner.setAdapter(adapter);
        //設定項目被選取之後的動作
        spinner.setOnItemSelectedListener(new Spinner.OnItemSelectedListener(){
            public void onItemSelected(AdapterView adapterView, View view, int position, long id){
                Toast.makeText(MainActivity.this, "您選擇"+adapterView.getSelectedItem().toString(), Toast.LENGTH_LONG).show();
            }
            public void onNothingSelected(AdapterView arg0) {
                Toast.makeText(MainActivity.this, "您沒有選擇任何項目", Toast.LENGTH_LONG).show();
            }
        });
    }
}

3. main.xml(Layout)

<?xml version="1.0" encoding="UTF-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent">
    <TextView
        android:id="@+id/textView"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content">
    </TextView>
    <Spinner
        android:id="@+id/spinnner"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content">
    </Spinner>
</LinearLayout>

4. 下拉式選單畫面