Android pull-down list (Spinner) Effects

Android pull-down list (Spinner) Effects

This article mainly introduces the Android drop-down list (Spinner) effect (implemented using C # and Java respectively). This article provides the implementation code and layout code in two languages, for more information, see

 

 

The effect is as follows:

C # implementation code

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Using Android. App; Using Android. OS; Using Android. Widget;   Namespace SpinnerDemo { [Activity (Label = "@ string/ApplicationName", MainLauncher = true, Icon = "@ drawable/icon")] Public class MainActivity: Activity { Private Spinner _ citySpinner; Private TextView _ cityNameView; Private ArrayAdapter <string> _ cityInfos;     Protected override void OnCreate (Bundle bundle) { Base. OnCreate (bundle );   SetContentView (Resource. Layout. Main ); _ CitySpinner = FindViewById <Spinner> (Resource. Id. sp_city ); _ CityNameView = FindViewById <TextView> (Resource.Id.txt _ cityName );   _ CityInfos = new ArrayAdapter <string> (this, Android. Resource. Layout. SimpleSpinnerDropDownItem ); _ CityInfos. Add ("Chengdu "); _ CityInfos. Add ("Lanzhou "); _ CityInfos. Add ("Wuhan "); _ CityInfos. Add ("Shanghai "); _ CitySpinner. Adapter = _ cityInfos; _ CitySpinner. ItemSelected + = CitySelectedEvent; }   Private void CitySelectedEvent (object sender, AdapterView. ItemSelectedEventArgs e) { _ CityNameView. Text = _ cityInfos. GetItem (e. Position ); } } }

Java implementation code

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Package com. example. halower. spinnerdemo;   Import android. OS. Bundle; Import android. support. v7.app. ActionBarActivity; Import android. view. View; Import android. widget. AdapterView; Import android. widget. ArrayAdapter; Import android. widget. Spinner; Import android. widget. TextView; Public class MainActivity extends ActionBarActivity { Private Spinner _ citySpinner; Private TextView _ cityNameView; Private ArrayAdapter <String> _ cityInfo; @ Override Protected void onCreate (Bundle savedInstanceState ){ Super. onCreate (savedInstanceState ); SetContentView (R. layout. activity_main ); _ CitySpinner = (Spinner) findViewById (R. id. sp_city ); _ CityNameView = (TextView) findViewById(R.id.txt _ cityName );   _ CityInfo = new ArrayAdapter <> (this, R. layout. support_simple_spinner_dropdown_item ); _ CityInfo. add ("Chengdu "); _ CityInfo. add ("Lanzhou "); _ CityInfo. add ("Wuhan "); _ CityInfo. add ("Shanghai "); _ CitySpinner. setAdapter (_ cityInfo ); _ CitySpinner. setOnItemSelectedListener (new AdapterView. OnItemSelectedListener (){ @ Override Public void onItemSelected (AdapterView <?> Parent, View view, int position, long id ){ _ CityNameView. setText (_ cityInfo. getItem (position )); }   @ Override Public void onNothingSelected (AdapterView <?> Parent ){   } }); } }

LayOut

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<RelativeLayout xmlns: android = "http://schemas.android.com/apk/res/android" Xmlns: tools = "http://schemas.android.com/tools" android: layout_width = "match_parent" Android: layout_height = "match_parent" android: paddingLeft = "@ dimen/activity_horizontal_margin" Android: paddingRight = "@ dimen/activity_horizontal_margin" Android: paddingTop = "@ dimen/activity_vertical_margin" Android: paddingBottom = "@ dimen/activity_vertical_margin" tools: context = ". MainActivity">   <Spinner Android: layout_width = "wrap_content" Android: layout_height = "wrap_content" Android: id = "@ + id/sp_city" Android: layout_alignParentTop = "true" Android: layout_alignParentRight = "true" Android: layout_alignParentEnd = "true" Android: layout_toEndOf = "@ + id/txt_cityName" Android: layout_toRightOf = "@ + id/txt_cityName"/> <TextView Android: layout_width = "wrap_content" Android: layout_height = "wrap_content" Android: text = "city" Android: id = "@ + id/txt_cityName" Android: layout_alignParentLeft = "true" Android: layout_alignParentStart = "true"/> </RelativeLayout>