Android basic entry control (4)

I. comprehensive use of buttons, TextView, EditText, RadioButton, RadioGroup, and CheckBox:

Layout file:

Activity_main.xml:

Strings. xml:

 
     
  
   
HelloWorld
      
  
   
Settings
      
  
   
Word concatenation
      
  
   
Submit
      
  
   
Name
      
  
   
Stars
      
  
   
Moon
      
  
   
Sun
      
  
   
Days
      
  
   
Location
      
  
   
Sea
  
 

MainActivity. java:

Package com. example. helloworld; import android. app. activity; import android. OS. bundle; import android. view. view; import android. widget. button; import android. widget. checkBox; import android. widget. compoundButton; import android. widget. compoundButton. onCheckedChangeListener; import android. widget. editText; import android. widget. radioButton; import android. widget. radioGroup; import android. widget. toast; public c Lass MainActivity extends Activity {// used to enter the name private EditText name; // create the RadioGroup object private RadioGroup rg; // create three RadioButton objects private RadioButton sun, moon, and stars; // create three CheckBox objects private CheckBox day, theearth, sea; // create the submit Button private Button submit; // The text String text = ""; @ Overrideprotected void onCreate (Bundle savedInstanceState) {super. onCreate (savedInstanceState); setContentView (R. layout. activity_main );// The findViewById () method is used to obtain the control in the layout file and obtain the control by Id. Name = (EditText) findViewById (R. id. name); rg = (RadioGroup) findViewById (R. id. radioGroup); sun = (RadioButton) findViewById (R. id. sun); moon = (RadioButton) findViewById (R. id. moon); stars = (RadioButton) findViewById (R. id. stars); day = (CheckBox) findViewById (R. id. day); theearth = (CheckBox) findViewById (R. id. theearth); sea = (CheckBox) findViewById (R. id. sea); submit = (Button) findViewById (R. id. submit); // select Add event for a single item. Rg. setOnCheckedChangeListener (new RadioGroup. onCheckedChangeListener () {@ Overridepublic void onCheckedChanged (RadioGroup group, int checkedId) {if (checkedId = sun. getId () {text + = sun. getText (). toString ();} else if (checkedId = moon. getId () {text + = moon. getText (). toString ();} else {text + = stars. getText (). toString () ;}}); // write only one event for multiple selections. The two can be filled in according to your needs. Day. setOnCheckedChangeListener (new OnCheckedChangeListener () {@ Overridepublic void onCheckedChanged (CompoundButton buttonView, boolean isChecked) {if (day. isChecked () {displayToast ("You like" + day. getText () ;}}); // click the Add button to display the selected content with toast. Submit. setOnClickListener (new View. onClickListener () {@ Overridepublic void onClick (View v) {String str = "like"; if (day. isChecked () {str + = day. getText () + ",";} if (theearth. isChecked () {str + = theearth. getText () + ",";} if (sea. isChecked () {str + = sea. getText () + ",";} displayToast (name. getText (). toString () + str + text) ;}}) ;}// toast, information prompt. Public void displayToast (String text) {Toast. makeText (getApplicationContext (), text, Toast. LENGTH_SHORT). show ();}}

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When multiple selections are selected, the toast information will pop up.

When you enter the name and select a single item, click the submit button to trigger the event and prompt you for the selected information.

2. Click the event:

There are three common handling methods for click events:

1) Anonymous internal class as event listening:

Implementation:

Button:

Code:

Button button; button = (Button) findViewById (R. id. click); button. setOnClickListener (new OnClickListener () {@ Overridepublic void onClick (View v) {displayToast ("click ");}});

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2). Internal class as listener:

Button:

Code:

Public class MainActivity extends Activity {@ Overrideprotected void onCreate (Bundle savedInstanceState) {super. onCreate (savedInstanceState); setContentView (R. layout. activity_main); Button button; button = (Button) findViewById (R. id. click); button. setOnClickListener (new ButtonOnClick ();} private final class ButtonOnClick implements OnClickListener {@ Overridepublic void onClick (View v) {displayToast ("click ");}} public void displayToast (String text) {Toast. makeText (getApplicationContext (), text, Toast. LENGTH_SHORT ). show () ;}@ Overridepublic boolean onCreateOptionsMenu (Menu menu) {// Inflate the menu; this adds items to the action bar if it is present. getMenuInflater (). inflate (R. menu. main, menu); return true ;}}

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3). Specify the listening method in the control:

Android: onClick = "specify method name"

Button:

Code:

Public class MainActivity extends Activity {@ Overrideprotected void onCreate (Bundle savedInstanceState) {super. onCreate (savedInstanceState); setContentView (R. layout. activity_main); Button button; button = (Button) findViewById (R. id. click);} // The method name and parameter name must be in this format and cannot be modified. Public void onClick (View v) {displayToast ("I have already clicked the button");} public void displayToast (String text) {Toast. makeText (getApplicationContext (), text, Toast. LENGTH_SHORT ). show () ;}@ Overridepublic boolean onCreateOptionsMenu (Menu menu) {// Inflate the menu; this adds items to the action bar if it is present. getMenuInflater (). inflate (R. menu. main, menu); return true ;}}

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There are other event listening methods. For details, refer.