Android——spinner控件實現讀取xml資源，省、市兩級互動

（1）首先在res文件夾下面的values中創建一個省市arrays.xml文件夾，如下

<?xml version="1.0" encoding="utf-8"?>
<resources>
<string-array name="province"> 
　　　 <item>-省份-</item> 
<item>河北省</item> 
<item>山西省</item>　　 
<item>北京市</item> 
</string-array> 
<string-array name="hb"> 
　　　 <item>-城市-</item> 
<item>承德市</item> 
<item>邯鄲市</item>　　 
<item>廊坊市</item> 
</string-array> 
<string-array name="bj"> 
　　　　 <item>-城市-</item> 
<item>海淀區</item> 
<item>朝陽區</item>　　 
<item>崇文區</item> 
</string-array> 
<string-array name="shx"> 
　　 <item>-城市-</item> 
<item>大同市</item> 
<item>臨汾市</item> 
</string-array> 
</resources>

(2)然后再布局文件中添加兩個spinner控件，xml布局代碼如下

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/LinearLayout1"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    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="com.example.spinner.MainActivity" >

    <Spinner
        android:id="@+id/spPro"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

    <Spinner
        android:id="@+id/spcity"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

</LinearLayout>

（3）到這里資源和布局界面已經搭好，接下來就是在MainActivity中用代碼來控制省市的聯動，詳解在代碼的注釋中，代碼如下

public class MainActivity extends Activity {
	private Spinner spPro, spCity;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		spPro = (Spinner) findViewById(R.id.spPro);
		spCity = (Spinner) findViewById(R.id.spcity);

		// 設置數據源
		ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(this, R.array.province,
				android.R.layout.simple_spinner_item);
		// 設置下拉列表的風格
		adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
		// 綁定數據源到spinner控件上
		spPro.setAdapter(adapter);

		//spinner選項選擇事件
		spPro.setOnItemSelectedListener(new OnItemSelectedListener() {

			@Override
			public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
				//此處的parent是指的spPro的下拉框
				Spinner spinner = (Spinner) parent;
				//通過getItemAtPosition(position)的方法來找到省項的名稱
				String pro = (String) spinner.getItemAtPosition(position);
				//設置市級的數據適配器
				ArrayAdapter<CharSequence> cityAdapter = ArrayAdapter.createFromResource(MainActivity.this, R.array.bj,
						android.R.layout.simple_spinner_item);
				//判斷，然后設置適配器
				if (pro.equals("河北省")) {
					cityAdapter = ArrayAdapter.createFromResource(MainActivity.this, R.array.hb,
							android.R.layout.simple_spinner_item);
				} else if (pro.equals("北京市")) {
					cityAdapter = ArrayAdapter.createFromResource(MainActivity.this, R.array.bj,
							android.R.layout.simple_spinner_item);
				} else if (pro.equals("山西省")) {
					cityAdapter = ArrayAdapter.createFromResource(MainActivity.this, R.array.shx,
							android.R.layout.simple_spinner_item);
				}
				spCity.setAdapter(cityAdapter);
			}

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

			}
		});

	}

}

　　最后運行的效果就是如下圖所示