Android常用控件-spinner



  

分类： Android基础 2011-03-25 15:25 2495人阅读 评论(1) 收藏 举报

android dropdown layout encoding class xml

Spinner类层次结构：

java.lang.Object
↳	android.view.View
	↳	android.view.ViewGroup
		↳	android.widget.AdapterView<T extends android.widget.Adapter>
			↳	android.widget.AbsSpinner
				↳	android.widget.Spinner

 

 

 

如何使用Spinner:

1、在布局xml文件中声明Spinner

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    <mce:script type="text/javascript" src="http://hi.images.csdn.net/js/blog/tiny_mce/themes/advanced/langs/zh.js" mce_src="http://hi.images.csdn.net/js/blog/tiny_mce/themes/advanced/langs/zh.js"></mce:script><mce:script type="text/javascript" src="http://hi.images.csdn.net/js/blog/tiny_mce/plugins/syntaxhl/langs/zh.js" mce_src="http://hi.images.csdn.net/js/blog/tiny_mce/plugins/syntaxhl/langs/zh.js"></mce:script>android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
  <TextView
        android:id="@+id/mytextview"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="10dip"
        android:text="@string/planet_prompt"
    />
<Spinner
    android:id="@+id/myspinner"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:drawSelectorOnTop="false"
    android:prompt="@string/write"
    />
</LinearLayout>

<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" <mce:script type="text/javascript" src="http://hi.images.csdn.net/js/blog/tiny_mce/themes/advanced/langs/zh.js" mce_src="http://hi.images.csdn.net/js/blog/tiny_mce/themes/advanced/langs/zh.js"></mce:script><mce:script type="text/javascript" src="http://hi.images.csdn.net/js/blog/tiny_mce/plugins/syntaxhl/langs/zh.js" mce_src="http://hi.images.csdn.net/js/blog/tiny_mce/plugins/syntaxhl/langs/zh.js"></mce:script>android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent" > <TextView android:id="@+id/mytextview" android:layout_width="fill_parent" android:layout_height="wrap_content" android:layout_marginTop="10dip" android:text="@string/planet_prompt" /> <Spinner android:id="@+id/myspinner" android:layout_width="fill_parent" android:layout_height="wrap_content" android:drawSelectorOnTop="false" android:prompt="@string/write" /> </LinearLayout> 

android:prompt属性指定了spinner弹出选择框时的标题

 

2、为Spinner指定数据

有两种方式为spinner指定数据：在代码中指定和加载资源文件中数据

先看在代码中指定的方式：

public class SpinnerActivity extends Activity {
    private Spinner spinner = null;
    private TextView myTextView = null;
    private static final String[] datas = {"China","Japan","USA"};
    private ArrayAdapter<String> arrayAdapter = null;
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        spinner = (Spinner)findViewById(R.id.myspinner);
        myTextView = (TextView)findViewById(R.id.mytextview);
        //定义了一个ArrayAdapter，将datas数组与simple_spinner_item绑定
        //android.R.layout.simple_spinner_item是由Android提供的一种标准spinner的布局
        arrayAdapter = new ArrayAdapter(this,android.R.layout.simple_spinner_item,datas);
        //声明当控件打开时的外观：为系统提供的simple_spinner_dropdown_item
        arrayAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item );

        spinner.setAdapter(arrayAdapter);
        //为spinner添加选择事件监听器
        spinner.setOnItemSelectedListener(new OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> parent, View view,
                                                    int position, long id) {
                myTextView.setText("你选择了"+datas[position]);
            }
            @Override
            public void onNothingSelected(AdapterView<?> parent) {
                myTextView.setText("OK");
            }
        });
        spinner.setVisibility(View.VISIBLE);

    }
}

public class SpinnerActivity extends Activity { private Spinner spinner = null; private TextView myTextView = null; private static final String[] datas = {"China","Japan","USA"}; private ArrayAdapter<String> arrayAdapter = null; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); spinner = (Spinner)findViewById(R.id.myspinner); myTextView = (TextView)findViewById(R.id.mytextview); //定义了一个ArrayAdapter，将datas数组与simple_spinner_item绑定 //android.R.layout.simple_spinner_item是由Android提供的一种标准spinner的布局 arrayAdapter = new ArrayAdapter(this,android.R.layout.simple_spinner_item,datas); //声明当控件打开时的外观：为系统提供的simple_spinner_dropdown_item arrayAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item ); spinner.setAdapter(arrayAdapter); //为spinner添加选择事件监听器 spinner.setOnItemSelectedListener(new OnItemSelectedListener() { @Override public void onItemSelected(AdapterView<?> parent, View view, int position, long id) { myTextView.setText("你选择了"+datas[position]); } @Override public void onNothingSelected(AdapterView<?> parent) { myTextView.setText("OK"); } }); spinner.setVisibility(View.VISIBLE); } } 

显示的效果如下：

 

另一种添加数据的方式：使用资源文件xml

先在资源文件中定义一个盛放spinner数据的xml文件：这里起名为：spinnerdata.xml,其内容如下：

 

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <string-array name="planets_array">
        <item>Mercury</item>
        <item>Venus</item>
        <item>Earth</item>
        <item>Mars</item>
        <item>Jupiter</item>
        <item>Saturn</item>
        <item>Uranus</item>
        <item>Neptune</item>
    </string-array>
</resources>

<?xml version="1.0" encoding="utf-8"?> <resources> <string-array name="planets_array"> <item>Mercury</item> <item>Venus</item> <item>Earth</item> <item>Mars</item> <item>Jupiter</item> <item>Saturn</item> <item>Uranus</item> <item>Neptune</item> </string-array> </resources>

xml文件名是什么不重要，重要的是你要有一个<string-array name="...">的元素来封装spinner的数据，当你产生了这样的xml,打开 你的gen文件下的R.java文件，你会发现Android开发工具为你的string-array添加了一个ID：

public final class R {
    public static final class array {
        public static final int planets_array=0x7f040000;//新添加的
    }
//...
}

public final class R { public static final class array { public static final int planets_array=0x7f040000;//新添加的 } //... } 

然后后在Activity类中，我们就可以加载上面的资源文件，并将其与spinner绑定，如下：

public class SpinnerActivity extends Activity {
    private Spinner spinner = null;
    private TextView myTextView = null;
    //CharSequence是一个接口，定义了一个盛放字符的有序集合，它还定义了一些方法来检索内部的字符
    private ArrayAdapter<CharSequence> arrayAdapter = null;
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        spinner = (Spinner) findViewById(R.id.myspinner);
        myTextView = (TextView) findViewById(R.id.mytextview);
        //创建一个ArrayAdapter，它将每个item与string array的数据绑定
        arrayAdapter = ArrayAdapter.createFromResource(this,
                R.array.planets_array, android.R.layout.simple_spinner_item);
        //定义spinner打开时的layout
        arrayAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        spinner.setAdapter(arrayAdapter);
        // 为spinner添加选择事件监听器
        spinner.setOnItemSelectedListener(new OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> parent, View view,
                    int position, long id) {
                //注意获取选择数据的方式：
                myTextView.setText("你选择了"+ parent.getItemAtPosition(position).toString());
            }
            @Override
            public void onNothingSelected(AdapterView<?> parent) {
                myTextView.setText("OK");
            }
        });
        spinner.setVisibility(View.VISIBLE);
    }
}

public class SpinnerActivity extends Activity { private Spinner spinner = null; private TextView myTextView = null; //CharSequence是一个接口，定义了一个盛放字符的有序集合，它还定义了一些方法来检索内部的字符 private ArrayAdapter<CharSequence> arrayAdapter = null; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); spinner = (Spinner) findViewById(R.id.myspinner); myTextView = (TextView) findViewById(R.id.mytextview); //创建一个ArrayAdapter，它将每个item与string array的数据绑定 arrayAdapter = ArrayAdapter.createFromResource(this, R.array.planets_array, android.R.layout.simple_spinner_item); //定义spinner打开时的layout arrayAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item); spinner.setAdapter(arrayAdapter); // 为spinner添加选择事件监听器 spinner.setOnItemSelectedListener(new OnItemSelectedListener() { @Override public void onItemSelected(AdapterView<?> parent, View view, int position, long id) { //注意获取选择数据的方式： myTextView.setText("你选择了"+ parent.getItemAtPosition(position).toString()); } @Override public void onNothingSelected(AdapterView<?> parent) { myTextView.setText("OK"); } }); spinner.setVisibility(View.VISIBLE); } }