Advanced article-user interface: 4. Common components in Android

1. Drop-down menu

In web development, HTML provides a drop-down list implementation that uses the <select> element to implement a drop-down list in which each drop-down list item uses the <option> representation. This is an essential interactive component in web development, and the corresponding implementation in Android is spinner.

Method One:

Static display of Spinner options in resource mode:

<spinner     android:layout_width= "match_parent"    android:layout_height= "wrap_content"    android:id= "@ +id/spinner2 "    android:entries=" @array/spingarr "    />

Data files:

<?xml version= "1.0" encoding= "Utf-8"?><resources> <string-array    name= "Spingarr" >     < Item> Beijing </item>      <item> Shanghai </item>      <item> Guangzhou </item>      <item> Shenzhen </item>      </string-array></resources>

Usage 2:

Dynamically display the Spinner option in code mode to add data to Spinner with the adapter

Package Com.example.testspanner;import Java.util.arraylist;import Java.util.list;import android.app.Activity; Import Android.os.bundle;import Android.widget.arrayadapter;import Android.widget.spinner;public class MainActivity Extends Activity {private Spinner spinner;private list<string> data_list;private arrayadapter<string> arr_    Adapter        @Override protected void OnCreate (Bundle savedinstancestate) {super.oncreate (savedinstancestate);        Setcontentview (R.layout.spinner);            Spinner = (spinner) Findviewbyid (R.id.spinner);        Data Data_list = new arraylist<string> ();        Data_list.add ("Beijing");        Data_list.add ("Shanghai");        Data_list.add ("Guangzhou");                Data_list.add ("Shenzhen"); Adapter arr_adapter= New Arrayadapter<string> (this, Android.        R.layout.simple_spinner_item, data_list); Set style Arr_adapter.setdropdownviewresource (Android.        R.layout.simple_spinner_dropdown_item); Load Adapter Spinner. Setadapter (Arr_adapter); }}

Layout file added:

< Spinner      Android:layout_width = "Match_parent"     android:layout_height= "Wrap_content"    android:id= "@+id/spinner"    />

2. Date picker

Btnchoosedata.setonclicklistener (NewView.onclicklistener () {@Override Public voidOnClick (view view) {NewDatepickerdialog (mainactivity. This,NewDatepickerdialog.ondatesetlistener () {@Override Public voidOndateset (DatePicker DatePicker,intIintI1,intI2) {System.out.println (String.Format ("%d-%d-%d", I,i1,i2)); }                },2016,1,1). Show (); }        });

Click the button to trigger a calendar selector.

3. Date Picker

Btnchoosedata.setonclicklistener (NewView.onclicklistener () {@Override Public voidOnClick (view view) {NewTimepickerdialog (mainactivity. This,NewTimepickerdialog.ontimesetlistener () {@Override Public voidOntimeset (Timepicker Timepicker,intIintI1) {System.out.println (String.Format ("%d:%d", I,I1)); }                },0,0,true). Show ();    }        }); }

Click on the button to trigger a time picker

4. Individual selection

 <RadiogroupAndroid:layout_width= "Wrap_content"Android:layout_height= "Wrap_content">        <RadioButtonAndroid:layout_width= "Wrap_content"Android:layout_height= "Wrap_content"Android:text= "New RadioButton1"Android:id= "@+id/rba" />        <RadioButtonAndroid:layout_width= "Wrap_content"Android:layout_height= "Wrap_content"Android:text= "New RadioButton2"Android:id= "@+id/rbb" />        <RadioButtonAndroid:layout_width= "Wrap_content"Android:layout_height= "Wrap_content"Android:text= "New RadioButton3"Android:id= "@+id/rbc" />        <RadioButtonAndroid:layout_width= "Wrap_content"Android:layout_height= "Wrap_content"Android:text= "New RadioButton4"Android:id= "@+id/rbd" />    </Radiogroup>

If you want to determine which option is selected in the radio group:

System.out.println (rba.ischecked ());

5. Multiple options

Just pay attention to multiple selection of objects there is a method oncheckedchanged ();

Advanced article-user interface: 4. Common components in Android