How to use Android drop-down menu spinner

The spinner control is also a list-type control, and its inheritance is as follows:

Java.lang.Object
? Android.view.View
? Android.view.ViewGroup
? Android.widget.adapterview<textends android.widget.adapter>
? Android.widget.AbsSpinner
? Android.widget.Spinner
Android.widget.Spinner inherits the Android.view.ViewGroup class.

In the Android UI development, Spinner (drop-down list) is always available, a simple custom Spinner production we just need to remember this important five steps, a Spinner can be applied and born.

(1) Create a new Android project with the name spinner. Build an activity at the same time, named Spinneractivity.

(2) Modify Res/layout/main.xml

[HTML]View Plaincopy

2. <? XML version= "1.0" encoding="Utf-8"?>
4. <linearlayout xmlns:android="http://schemas.android.com/apk/res/android"
6. android:orientation="vertical"
8. android:layout_width="fill_parent"
10. android:layout_height="fill_parent"
12. >
14. <TextView
16. android:id = "@+id/textview_city"
18. android:layout_width = "Wrap_content"
20. android:layout_height = "Wrap_content"
22. Android:text = "City:"
24. />
26. <!--define a city information drop-down menu --
28. <Spinner
30. android:id = "@+id/spinner_city"
32. android:layout_width = "Wrap_content"
34. android:layout_height ="Wrap_content" >
36. </Spinner >
38. </linearlayout>

(3) Spinneractivity.java code.

[Java]View Plaincopy

2. Package cn.com;
6. Import java.util.ArrayList;
8. Import java.util.List;
12. Import android.app.Activity;
14. Import Android.os.Bundle;
16. Import android.view.MotionEvent;
18. Import Android.view.View;
20. Import Android.widget.AdapterView;
22. Import Android.widget.ArrayAdapter;
24. Import Android.widget.Spinner;
26. Import Android.widget.TextView;
30. Public class Spinneractivity extends Activity {
32. /** Called when the activity is first created. * /
34. private List<string> List = new arraylist<string> ();
36. private TextView Mytextview;
38. private Spinner Myspinner;
40. private arrayadapter<string> adapter;
42. @Override
44. public void OnCreate (Bundle savedinstancestate) {
46. super.oncreate (savedinstancestate);
48. Setcontentview (R.layout.main);
50. //First step: Add a list of drop-down list items, and the items you add here are the menu items for the drop-down list
52. List.add ("Beijing");
54. List.add ("Shanghai");
56. List.add ("Shenzhen");
58. List.add ("Fuzhou");
60. List.add ("Xiamen");
62. Mytextview = (TextView) Findviewbyid (r.id.textview_city);
64. Myspinner = (Spinner) Findviewbyid (r.id.spinner_city);
66. ///Step Two: Define an adapter for the drop-down list, using the list defined in the previous section.
68. adapter = New Arrayadapter<string> (this,android.    R.layout.simple_spinner_item, list);
70. //Step three: Set the menu style for the adapter drop-down list.
72. Adapter.setdropdownviewresource (Android. R.layout.simple_spinner_dropdown_item);
74. //Step Fourth: Add the adapter to the drop-down list
76. Myspinner.setadapter (adapter);
78. //Fifth step: Set the response of various events for the drop-down list, the Response menu is selected
80. Myspinner.setonitemselectedlistener (new Spinner.onitemselectedlistener () {
82. public void onitemselected (adapterview<?> arg0, View arg1, int arg2, long arg3) {
84. //TODO auto-generated method stub
86. / * Bring the value of the selected Myspinner into the Mytextview * /
88. Mytextview.settext ("You have selected:" + Adapter.getitem (arg2));
90. / * Display the Myspinner * /
92. Arg0.setvisibility (view.visible);
94. }
96. public void onnothingselected (adapterview<?> arg0) {
98. //TODO auto-generated method stub
100. Mytextview.settext ("NONE");
102. Arg0.setvisibility (view.visible);
104. }
106. });
108. / * drop-down menu popup content options Touch-screen event handling * /
110. Myspinner.setontouchlistener (new Spinner.ontouchlistener () {
112. Public Boolean OnTouch (View V, motionevent event) {
114. //TODO auto-generated method stub
116. /** 
118. *
120. */
122. return false;
124. }
126. });
128. / * drop-down menu popup content options Focus Change Event handling * /
130. Myspinner.setonfocuschangelistener (new Spinner.onfocuschangelistener () {
132. public void Onfocuschange (View V, boolean hasfocus) {
134. //TODO auto-generated method stub
138. }
140. });
142. }
144. }

The results of the operation are as follows:

How to use Android drop-down menu spinner