Android界面组件3--ListView Spinner

1.ListView

ListView是手机系统中使用非常广泛的一种组件，它以垂直列表的形式显示所有列表项。

创建ListView有两种方式：

      直接使用ListView进行创建

      让Activity继承ListActivity

1)直接使用ListView进行创建

在list_layout.xml中代码如下：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >
	<TextView 
	    android:layout_width="fill_parent"
	    android:layout_height="wrap_content"
	    android:text="名单"
	    />
	<ListView 
	    android:layout_width="fill_parent"
	    android:layout_height="wrap_content"
	    android:id="@+id/nameList"
	    />
	    
	

</LinearLayout>

在ListViewDemo.java中代码如下：

package cn.class3g.activity;

import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ArrayAdapter;
import android.widget.ListView;

public class ListViewDemo extends Activity implements OnItemClickListener{
	ListView nameList = null;
	String[] names = {"张三","李四","王五","宋留","猪八"};
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.list_layout);
		findView();
	}
	private void findView() {
		nameList = (ListView) this.findViewById(R.id.nameList);
		ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1,names);
		nameList.setAdapter(adapter);
		
		nameList.setOnItemClickListener(this);
	}
	//覆盖监听器接口OnItemClickListener的抽象方法
	public void onItemClick(AdapterView<?> arg0, View arg1, int arg2, long arg3) {
		Log.i("TAG", names[arg2] + "position = " + String.valueOf(arg2) + "row_id = " + String.valueOf(arg3));
		
	}
	
}

2）让Activity继承ListActivity

在ListActivityDemo.java中代码如下：

package cn.class3g.activity;

import android.app.ListActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.ListView;

public class ListActivityDemo extends ListActivity {

	String[] names = {"张三","李四","王五","宋留","猪八"};
	
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		
		ArrayAdapter adapter = new ArrayAdapter(this, android.R.layout.simple_list_item_1,names);
		this.setListAdapter(adapter);
	}

	//覆盖父类方法，无需专门创建和注册监听器
	protected void onListItemClick(ListView l, View v, int position, long id) {
		
		Log.i("TAG", names[position] + "position = " + String.valueOf(position) + "row_id = " + String.valueOf(id));
	}
	
}

两种方法显示效果相同：

2.Spinner

Spinner其实就是一个列表选择框

在arrays.xml中指定数组资源

<?xml version="1.0" encoding="utf-8"?>
<resources>
	<string-array name="sports">
	    <item>足球</item>
	    <item>篮球</item>
	    <item>乒乓球</item>
	    <item>网球</item>
	</string-array>
    
</resources>

在spinner_layout.xml中代码如下：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <TextView 
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="请选择一个运动项目"
        />
    <Spinner 
        android:id="@+id/sportsSp"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:prompt="@string/spinner_prompt"
        android:entries="@array/sports"
        />

</LinearLayout>

在SpinnerDemo.java中代码如下：

package cn.class3g.activity;

import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemSelectedListener;
import android.widget.Spinner;
import android.widget.TextView;

public class SpinnerDemo extends Activity implements OnItemSelectedListener{
	
	Spinner sportSp = null;
	
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.spinner_layout);
		findViews();
	}

	private void findViews() {
		sportSp = (Spinner) this.findViewById(R.id.sportsSp);
		sportSp.setOnItemSelectedListener(this);
		sportSp.performClick();
	}

	@Override
	public void onItemSelected(AdapterView<?> arg0, View arg1, int arg2,
			long arg3) {
		TextView tv = (TextView) arg1;
		Log.i("TAG", tv.getText().toString());
		
		
	}

	@Override
	public void onNothingSelected(AdapterView<?> arg0) {
		
		
	}
	
}

显示效果如下：