Android--下拉框

 

一. 實現效果圖如下

 

　　Android 中的下拉框為Spinner 組件,其效果圖如上圖片

 

二. 實現代碼

　　布局代碼如下

<?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" >

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

　　設置數據源

public class MainActivity extends Activity {
    private String[] items=new String[]{"北京","上海","廣州","長沙"};
    private Animation myAnimation=null;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        ArrayAdapter<String> source=new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, items);
        
        Spinner ddlCity=(Spinner)findViewById(R.id.ddlCity);
        ddlCity.setAdapter(source);
        
        ddlCity.setOnItemSelectedListener(new Spinner.OnItemSelectedListener(){

            @Override
            public void onItemSelected(AdapterView<?> arg0, View arg1,
                    int arg2, long arg3) {
                new AlertDialog.Builder(MainActivity.this)
                .setTitle("提示")
                .setMessage("您選擇的是"+items[arg2])
                .setPositiveButton("確定", null)
                .show();
            }

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

　　Spinner的數據源使用ArrayAdapter

ArrayAdapter<String> source=new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, items);

　　這里需要制定下拉框Item的布局文件,這里選用系統中自帶的布局文件