安卓开发—下拉列表

安卓界面的下拉列表主要使用<Spinner>组件；其中的数组的创建主要分为静态创建和动态创建，下面主要写的静态数组的创建；部分代码如下所示“

xml:

<RelativeLayout 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:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity" >

    <TextView
        android:id="@+id/txt01"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/hello_world" />
    <Spinner
        android:id="@+id/sp01"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:entries="@array/city"
        android:layout_toRightOf="@+id/txt01"
        />
    <TextView
        android:id="@+id/txt02"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="你选择的是："
        android:layout_below="@+id/txt01"
        android:layout_margin="50dp"
        />

</RelativeLayout>

资源文件代码:

<resources>
    <string-array name="city">
        <item >北京</item>
        <item >上海</item>
        <item >广州</item>
        <item >深圳</item>
        <item >成都</item>
        <item >西安</item>
        <item >香港</item>
        
    </string-array>
    
</resources>

JAVA代码：

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

public class MainActivity extends Activity {
    private TextView txt2;
    private Spinner sp1;
    private StringBuilder result=new StringBuilder();
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        txt2=(TextView)this.findViewById(R.id.txt02);
        sp1=(Spinner)this.findViewById(R.id.sp01);
        final String[] cities_list=getResources().getStringArray(R.array.city);
        final String wy=txt2.getText().toString();
        sp1.setOnItemSelectedListener(new OnItemSelectedListener(){

            @Override
            public void onItemSelected(AdapterView<?> arg0, View arg1,
                    int arg2, long arg3) {
                // TODO Auto-generated method stub
                result.delete(0, result.length());
                String ci=cities_list[arg2];
                result.append(wy.toString()+ci.toString());
                txt2.setText(result);
            }

            @Override
            public void onNothingSelected(AdapterView<?> arg0) {
                // TODO Auto-generated method stub
                
            }
        });
        
    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }
    
}