Recepty, články, nápady, programování. Dříve dum-zahrada, finance, internet a know-how.okhelp.cz Pro lepší výsledky hledání používejte i diakritiku.

RadioButton RadioGroup Java Android example


RadioButton RadioGroup Android example source code for Android developer
Example for *.xml files

       <RadioGroup android:id="@+id/idRadio_group"

            <RadioButton android:id="@+id/idRadio_1"
            <RadioButton android:id="@+id/idRadio_2"
            <RadioButton android:id="@+id/idRadio_3"


Example for *.java files

// import
import android.widget.RadioGroup;
// get handle of RadioGroup
RadioGroup  mRadioGroup = (RadioGroup) findViewById(R.id.idRadio_group);

// which RadioButton is selected for example in some function body
         int nUnits = 10; // decimetry
    	 int nIdRadio = mRadioGroup.getCheckedRadioButtonId();
    			if(nIdRadio == R.id.idRadio_1) nUnits = 1; // metr
    			else if(nIdRadio == R.id.idRadio_2) nUnits = 10; // decimetr
    			else if(nIdRadio == R.id.idRadio_3) nUnits = 100; // cm
    			else if(nIdRadio == R.id.idRadio_4) nUnits = 1000; // mm

// listener for RadioGroup Java Android example
                new RadioGroup.OnCheckedChangeListener() {
                    public void onCheckedChanged(RadioGroup group,
                            int checkedId) {
                        Log.v("Selected", "New radio item selected: " + checkedId);

397LW NO topic_id


Další témata ....(Topics)


Android studio list of useful shortcuts or like Eclipse | android-studio-list-of-useful-shortcuts

File -> Settings -> Keymap you can do select Eclipse keymap from drop down menu

Ctrl+Shift+A (Help | Find Action on the main menu) and start typing the name of the action. Choose the desired action from the suggestion list.

Ctrl+Click (on Windows) or Cmd+Click (on MacOS) a tab in the editor to navigate to any part of the file path. Select the necessary element in the drop-down, and the corresponding file path opens in an external browser (e.g., in the Explorer, if your OS is Windows).


Find - Rename

Ctrl+F find

Refactor | Rename: Shift+F6  ( +F6)

Find and replace: CTRL + R

Go to variable declaration: CTRL + B

Ctrl+Shift+I (View | Quick Definition)

Ctrl+Alt+F7  (Edit | Find | Show Usages in the main menu)

Ctrl+Shift+F find in project

Ctrl+Shift+F7 (Edit | Find | Highlight Usages in File) to quickly highlight usages of some variable in the current file.
Use F3 and Shift+F3 keys to navigate through highlighted usages.
Press Escape to remove highlighting.

Ctrl+W (extend selection) in the editor selects the word at the caret and then selects expanding areas of the source code. For example, it may select a method name, then the expression that calls this method, then the whole statement, then the containing block, etc. You can also select the word at the caret and the expanding areas of the source code by double-clicking the target areas in the editor.

To search through the classes, files, tool windows, actions, settings, and symbols of your project by double pressing the Shift key

Ctrl+P (View | Parameter Info) e.g. localURL = new URL(localUrlString); select localUrlString and press Ctrl + P

Show html documentation tooltips:  CTRL + Q



Comment uncomment single line: CTRL + /

Comment uncomment selected text: CTRL + SHIFT + /

Code completion (Ctrl+Space)

Alt key and mouse pointer dragging for column selection

If nothing is selected in the editor, and you press Ctrl+C, then the whole line at caret is copied to the clipboard.

Ctrl + Delete  delete word from caret to end.

Ctrl + Backspace delete word from caret to start.

Duplicate line: CTRL + D

To compare two directories,or  jar files, select one or both of them in the Project view and press Ctrl+D.

Editor Delete Line: CTRL + Y

Move line UP, DOWN. Select a code fragment and press Ctrl+Shift+Up or Ctrl+Shift+Down.

To open any class or file in the editor at the desired line, press Ctrl+Shift+N (Navigate | File), start typing the name, and choose the one from the suggestion list. Then type the colon (:) and a line number

Ctrl+Shift+Enter to complete a current statement such as if, do-while, try-catch, return (or a method call)

Alt+Enter to invoke a quick fix or intention action, press the right arrow key to reveal the list of additional options.

To quickly review your recent changes to the project: Alt+Shift+C

Code Completion, you can accept the currently highlighted selection in the popup list with the period character (.), comma (,), semicolon (;), space and other characters.

Quickly move between methods in the editor:  Alt+Up and Alt+Down

Ctrl+Shift+J shortcut joins two lines into one and removes unnecessary space to match your code style

Ctrl+Shift+V to choose and insert recent clipboard contents into the text

Inheritance hierarchy for a selected class: Ctrl+H

Right-clicking on a breakpoint marker  you can quickly enable/disable the breakpoint or adjust its properties.

Evaluate the value of any expression while debugging the program, select its text in the editor (you may press a Ctrl+W a few times to efficiently perform this operation) and press Alt+F8.

Quickly evaluate the value of any expression while debugging the program, hold Alt and click this expression to see its value and calculate it, call a method, etc.

You can use the Extract Variable refactoring even on incomplete statements. Just select the necessary block in the editor and press Ctrl+Alt+V.

To open any particular method or field in editor: Ctrl+Alt+Shift+N

Add unimplemented methods: CTRL + I

Override methods: CTRL + O

Format code: CTRL + ALT + L

Show project: ALT + 1

Show logcat: ALT + 6

Hide project - logcat: SHIFT + ESC

Build: CTRL + F9

Build and Run: CTRL + F10

Alt+Shift+F10  access the Run/Debug dropdown on the main toolbar

Collapse all: CTRL + SHIFT + NumPad +

Expand all: CTRL + SHIFT + NumPad -

Get Context Java Android example | get-context-java-android-example

getContext() getApplicationContext() method Java Android example source

Context myContext_1 = ThisClassName.this; // to open a Dialog
Context myContext_2 = getContext();
Context myContext_3 = this.getContext();
Context myContext_4 = this;
Context myContext_5 = this.getApplicationContext ();

OnClickListener getImageBtnOnClick = new OnClickListener() {
public void onClick(View view) {
Context context = view.getContext();

// Toast
Toast.makeText(getApplicationContext(), "Context == getApplicationContext "
, Toast.LENGTH_SHORT).show();

// store Context in public class
public class MyActivity extends Activity {
public static Context myCnt = null;
protected void onCreate(Bundle icicle) {
myCnt = this;
// or
// MyStorage.setContext(this);

// cntxFromStorage == this
Context cntxFromStorage = MyStorage.getContext();

public class MyStorage
private static Context cntStorageContext = null;

public static Context getContext() {
return cntStorageContext;

public static void setContext(Context context) {
MyStorage.cntStorageContext = context;


class DataBaseHelper extends SQLiteOpenHelper {
// get MyActivity context
Context cnt = MyStorage.getContext();



List LinkedList add sort find Item in Java example | list-linkedlist-add-sort-find-item-in-java-example

List LinkedList Collections add sort find search Item, get searched item to string in Java example.


import java.util.Collections;
import java.util.LinkedList;
import java.util.List;

public class MainClass {
	public static void main(String[] arg) {
		String[] arrayOfString = {"nothing", "Hello", "people"
				, "bye-bye", "hello", "world!", "End" };
                   List<String> arrayList = new LinkedList<String>();
                   for(String s: arrayOfString)

		    // foreach
		    for (String str: arrayList)
		    Object objMin = Collections.min(arrayList);
		    System.out.println("Min is: " + objMin);
		    Object objMax = Collections.max(arrayList);
		    System.out.println("Max is: " + objMax);
		    int index = Collections.binarySearch(arrayList, "people");
		    System.out.println("Index of people is: " + index);
		    // print word on index 5
		    System.out.println("Index 5 is: " + arrayList.get(5));
                    String sItem = arrayList.get(5); // get item from index 5 to string
Min is: End
Max is: world!
Index of people is: 5
Index 5 is: people

Shared Preferences file path Android | shared-preferences-file-path-android


String TAG = "MyActivityName";
File f = new File("/data/data/"+this.getPackageName()
	Log.d(TAG, "exist");
	Log.d(TAG, "not exist");


Not request focus EditText if startup Android | not-request-focus-edittext-if-startup-android

Not request focus EditText if startup Android - hide keyboard if startup.

Remove: from EditText

Create a LinearLayout and set the:
attributes android:focusable="true" android:focusableInTouchMode="true"

        android:orientation="vertical" >

Editace: 2011-09-26 20:48:27
Počet článků v kategorii: 397

11 Share