关于下拉框的一些应用
做下拉框可以利用系统自带的方法创建adpter，通过数组传入需要的字符串。
布局文件如下
java代码如下：package com.example.mydrawsector;import java.util.ArrayList;import java.util.List;import android.app.Activity;import android.os.Bundle;import android.view.View;import android.widget.AdapterView;import android.widget.ArrayAdapter;import android.widget.Button;import android.widget.Spinner;import android.widget.TextView; public class SpinnerActivity extends Activity { /** Called when the activity is first created. */ private List<String> list = new ArrayList<String>(); private List<String> list1 = new ArrayList<String>(); private TextView myTextView; private TextView myTextView1; private Spinner mySpinner; private Spinner mySpinner1; private ArrayAdapter<String> adapter; private ArrayAdapter<String> adapter1; private Button button; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); //第一步：添加一个下拉列表项的list，这里添加的项就是下拉列表的菜单项 list.add("北京"); list.add("上海"); list.add("深圳"); list.add("南京"); list.add("重庆"); list1.add("公交"); list1.add("地铁"); list1.add("自驾游"); button = (Button)findViewById(R.id.button); myTextView = (TextView)findViewById(R.id.TextView_Show); mySpinner = (Spinner)findViewById(R.id.spinner_City); myTextView1 = (TextView)findViewById(R.id.TextView_Show1); mySpinner1 = (Spinner)findViewById(R.id.spinner_City1); //第二步：为下拉列表定义一个适配器，这里就用到里前面定义的list。 adapter = new ArrayAdapter<String>(this,android.R.layout.simple_spinner_item, list); //第三步：为适配器设置下拉列表下拉时的菜单样式。 adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item); //第四步：将适配器添加到下拉列表上 adapter1 = new ArrayAdapter<String>(this,android.R.layout.simple_spinner_item, list1); //第三步：为适配器设置下拉列表下拉时的菜单样式。 adapter1.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item); mySpinner.setAdapter(adapter); mySpinner1.setAdapter(adapter1); //第五步：为下拉列表设置各种事件的响应，这个事响应菜单被选中 mySpinner.setOnItemSelectedListener(new Spinner.OnItemSelectedListener(){ @SuppressWarnings("unchecked") public void onItemSelected(AdapterView arg0, View arg1, int arg2, long arg3) { // TODO Auto-generated method stub /* 将所选mySpinner 的值带入myTextView 中*/ myTextView.setText("您选择的是："+ adapter.getItem(arg2)); /* 将mySpinner 显示*/ arg0.setVisibility(View.VISIBLE); isShowOKButton(); } @SuppressWarnings("unchecked") public void onNothingSelected(AdapterView arg0) { // // TODO Auto-generated method stub // myTextView.setText("NONE"); // arg0.setVisibility(View.VISIBLE); } }); mySpinner1.setOnItemSelectedListener(new Spinner.OnItemSelectedListener(){ @SuppressWarnings("unchecked") public void onItemSelected(AdapterView arg0, View arg1, int arg2, long arg3) { // TODO Auto-generated method stub /* 将所选mySpinner 的值带入myTextView 中*/ myTextView1.setText("您选择的是："+ adapter1.getItem(arg2)); /* 将mySpinner 显示*/ arg0.setVisibility(View.VISIBLE); isShowOKButton(); } @SuppressWarnings("unchecked") public void onNothingSelected(AdapterView arg0) { // TODO Auto-generated method stub // myTextView1.setText("NONE"); // arg0.setVisibility(View.VISIBLE); } }); // /*下拉菜单弹出的内容选项触屏事件处理*/ // mySpinner.setOnTouchListener(new Spinner.OnTouchListener(){ // public boolean onTouch(View v, MotionEvent event) { // // TODO Auto-generated method stub // /* 将mySpinner 隐藏，不隐藏也可以，看自己爱好*/ // v.setVisibility(View.INVISIBLE); // return false; // } // }); /*下拉菜单弹出的内容选项焦点改变事件处理*/ mySpinner.setOnFocusChangeListener(new Spinner.OnFocusChangeListener(){ public void onFocusChange(View v, boolean hasFocus) { // TODO Auto-generated method stub v.setVisibility(View.VISIBLE); } }); } public void isShowOKButton(){ if((myTextView.getText()!=null||myTextView.getText()!="")&&(myTextView1.getText()!=null||myTextView1.getText()!="")){ button.setVisibility(View.VISIBLE); } } }
小结
1.Spinner中textview显示的内容为list中第一个元素。
2.继续学习自定义风格的下拉框并且改变spinner的默认值。