Android学习笔记(二十五)

Spinner

SpinnerActivity

package org.wp.activity;

import java.util.ArrayList;
import java.util.List;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.Spinner;
import android.widget.Toast;

public class SpinnerActivity extends Activity {
	private Spinner spinnerOne;
	private Spinner spinnerTwo;
	private Button button;

	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);
		spinnerOne = (Spinner) this.findViewById(R.id.spinnerOne);

		// createFromResource()方法创建ArrayAdapter对象
		// 第二个参数引用了strings.xml中的数组
		// 第三个参数指定所使用的样式
		ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(
				SpinnerActivity.this, R.array.planets_array,
				android.R.layout.simple_spinner_item);
		// 设置Spinner中每个条目的样式
		adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);

		spinnerOne.setAdapter(adapter);
		spinnerOne.setPrompt("行星");
		spinnerOne.setOnItemSelectedListener(new Spinner.OnItemSelectedListener() {
			@Override
			public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
				String selected = parent.getItemAtPosition(position).toString();
				Toast.makeText(SpinnerActivity.this, selected, Toast.LENGTH_SHORT).show();
			}

			@Override
			public void onNothingSelected(AdapterView<?> parent) {
			}
		});

		spinnerTwo = (Spinner) this.findViewById(R.id.spinnerTwo);
		button = (Button) this.findViewById(R.id.buttonId);
		button.setOnClickListener(new View.OnClickListener() {
			@Override
			public void onClick(View v) {
				List<String> list = new ArrayList<String>();
				list.add("选项1");
				list.add("选项2");
				list.add("选项3");
				//第二个参数指定了下拉菜单当中每一个条目的样式
				//第三个参数指定了TextView控件的ID
				ArrayAdapter adapter = new ArrayAdapter(SpinnerActivity.this,
						R.layout.item, R.id.textViewId, list);
				spinnerTwo.setAdapter(adapter);
			}
		});
	}
}

main.xml

<?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"
    >
	<Spinner
		android:layout_width="fill_parent"
		android:layout_height="wrap_content"
		android:id="@+id/spinnerOne"
		/>
	<Spinner
		android:layout_width="fill_parent"
		android:layout_height="wrap_content"
		android:id="@+id/spinnerTwo"
		/>	
	<Button
		android:layout_width="wrap_content"
		android:layout_height="wrap_content"
		android:text="生成数据"
		android:id="@+id/buttonId"
		/>	
</LinearLayout>

 

item.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
	android:layout_width="fill_parent"
	android:layout_height="fill_parent"
	>
	<TextView
		android:layout_width="fill_parent"
		android:layout_height="wrap_content"
		android:id="@+id/textViewId"
		/>
</LinearLayout>

strings.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
	<string name="hello">Hello World, SpinnerActivity!</string>
	<string name="app_name">Spinner</string>
	<string-array name="planets_array">
		<item>水星</item>
		<item>金星</item>
		<item>地球</item>
		<item>火星</item>
		<item>木星</item>
		<item>土星</item>
		<item>天王星</item>
		<item>海王星</item>
	</string-array>
</resources>