onSaveInstanceState() onRestoreInstanceState() basic Android example

AD MOB


public class MyClass extends Activity {
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
       }
	 String sMyText = "some text";
	 int nMyInt = 10;

 @Override
 protected void onSaveInstanceState(Bundle outState) {
     // Save away the original text, so we still have it if the activity
     // needs to be killed while paused.
     outState.putString("my_text", sMyText);
     outState.putInt("my_int", nMyInt);
     Toast.makeText(this, "onSaveInstanceState()", Toast.LENGTH_LONG).show();
Log.i("onSaveInstanceState", "onSaveInstanceState()");
}
 String sNewMyText = "";
 int nNewMyInt = 0;
 
 @Override
 protected void onRestoreInstanceState(Bundle savedInstanceState) {
     super.onRestoreInstanceState(savedInstanceState);
     // restore saved values
     sNewMyText = savedInstanceState.getString("my_text");
     nNewMyInt = savedInstanceState.getInt("my_int");
     Toast.makeText(this, "onRestoreInstanceState()", Toast.LENGTH_LONG).show();
     Log.i("onRestoreInstanceState", "onRestoreInstanceState()");
     
 }
}

397LW NO topic_id

Další témata ....(Topics)

219

SparseArray instead HashMap Android example | sparsearray-instead-hashmap-android-example

Old code with HashMap


 Map<Integer, Bitmap> _bitmapCache = new HashMap<Integer, Bitmap>();
   private void fillBitmapCache() {
        _bitmapCache.put(R.drawable.icon, BitmapFactory.decodeResource(getResources(), R.drawable.icon));
        _bitmapCache.put(R.drawable.abstrakt, BitmapFactory.decodeResource(getResources(), R.drawable.abstrakt));
        _bitmapCache.put(R.drawable.wallpaper, BitmapFactory.decodeResource(getResources(), R.drawable.wallpaper));
        _bitmapCache.put(R.drawable.scissors, BitmapFactory.decodeResource(getResources(), 
    }

Bitmap bm = _bitmapCache.get(R.drawable.icon);

Lint warning:
Use new SparseArray(...) instead for better performance
Issue: Looks for opportunities to replace HashMaps with the more efficient SparseArray
Id: UseSparseArrays

New code with SparseArray


 SparseArray<Bitmap> _bitmapCache = new SparseArray<Bitmap>();
   private void fillBitmapCache() {
        _bitmapCache.put(R.drawable.icon, BitmapFactory.decodeResource(getResources(), R.drawable.icon));
        _bitmapCache.put(R.drawable.abstrakt, BitmapFactory.decodeResource(getResources(), R.drawable.abstrakt));
        _bitmapCache.put(R.drawable.wallpaper, BitmapFactory.decodeResource(getResources(), R.drawable.wallpaper));
        _bitmapCache.put(R.drawable.scissors, BitmapFactory.decodeResource(getResources(), 
    }

Bitmap bm = _bitmapCache.get(R.drawable.icon);

SparseArray methods:
//developer.android.com/reference/android/util/SparseArray.html

259

Shuffle Array of String Java Example | shuffle-array-of-string-java-example


       String[] sAr = new String[] {"one","two","three"};
       List<String> wordList = Arrays.asList(sAr);
       Collections.shuffle( wordList);
       String[]myShuffledArray = wordList.toArray(new String[wordList.size()]);

Android Emulator PC keyboard shortcuts | android-emulator-pc-keyboard-shortcuts

Basic shortcuts for Android Emulator.

Emulated Device Key	Keyboard Key
Home	HOME
Menu (left softkey)	F2 or Page-up button
Star (right softkey)	Shift-F2 or Page Down
Back	ESC
Call/dial button	F3
Hangup/end call button	F4
Search	F5
Power button	F7
Audio volume up button	KEYPAD_PLUS, Ctrl-5
Audio volume down button	KEYPAD_MINUS, Ctrl-F6
Camera button	Ctrl-KEYPAD_5, Ctrl-F3
Switch to previous layout orientation (for example, portrait, landscape)	KEYPAD_7, Ctrl-F11
Switch to next layout orientation (for example, portrait, landscape)	KEYPAD_9, Ctrl-F12
Toggle cell networking on/off	F8
Toggle code profiling	F9 (only with -trace startup option)
Toggle fullscreen mode	Alt-Enter
Toggle trackball mode	F6
Enter trackball mode temporarily (while key is pressed)	Delete
DPad left/up/right/down	KEYPAD_4/8/6/2
DPad center click	KEYPAD_5
Onion alpha increase/decrease	KEYPAD_MULTIPLY(*) / KEYPAD_DIVIDE(/)

More about Android Emulator

Emulator window was out of view and was recentred - Android emulator warning | emulator-window-was-out-of-view-and-was-recentred-android-emulator-warning

Emulator window was out of view and was recentred
Emulator] WARNING: Data partition already in use. Changes will not persist!
Emulator] WARNING: SD Card image already in use: C:\Documents and Settings\user_name\.android\avd\hvga21_up1_7.avd/sdcard.img
Emulator] WARNING: Cache partition already in use. Changes will not persist!

Basic step
Try restart Eclipse if using from menu File->Restart

Other solutions

Solution 1: try restart ADB server
//android.okhelp.cz/how-quickly-restart-adb-exe-adb-server-android-emulator-example/

Solution 2:

Delete Run Configuration

//android.okhelp.cz/android-emulator-wont-run-application-started-from-eclipse/

Solution 3:
Try delete:


c:\Documents and Settings\user_name\.android\avd\my_avd.avd\cache.img
c:\Documents and Settings\user_name\.android\avd\my_avd.avd\userdata-qemu.img

Try solution 4:
Eclipse menu select Window->Preferences->Android

Windows 32

FROM: C:\Program Files\Android\android-sdk
TO: C:\PROGRA~1\Android\android-sdk

Windows 64

FROM: C:\Program Files (x86)\Android\android-sdk
TO: C:\PROGRA~2\Android\android-sdk

Map TreeMap get key by value Java Android example | map-treemap-get-key-by-value-java-android-example

Get key by value from Map Java Android example

MainClass.java


import java.util.HashSet;
import java.util.Iterator;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
import java.util.TreeMap;

public class MainClass {
	public static void main(String[] arg) {

		// english;germany dictionary
		String[] arrayOfString = { "one;eine", "two;zwei", "two sets of;zwei"
				, "three;drei", "four;vier" };

		Map<String, String> map = new TreeMap<String, String>();

		for (String s : arrayOfString) {
			String[] array = s.split(";");
			String sKey = "", sValue = "";
			if (array.length > 1) {
				sKey = array[0];
				sValue = array[1];
				map.put(sKey, sValue);
			}
		}

		if (map.containsValue("zwei")) {
			Set<String> references = getKeysByValue(map, "zwei");
			 Iterator<String> it = references.iterator();
			    while (it.hasNext()) {
			      String key = (String) it.next();
			      String value = map.get(key);
			      System.out.println(key + " = " + value);
			    }
		}

	}

	public static <T, E> Set<T> getKeysByValue(Map<T, E> map, E value) {
		Set<T> keys = new HashSet<T>();
		for (Entry<T, E> entry : map.entrySet()) {
			if (entry.getValue().equals(value)) {
				keys.add(entry.getKey());
			}
		}
		return keys;
	}
}
/*
two = zwei
two sets of = zwei
 */

Editace: 2011-10-08 15:38:52
Počet článků v kategorii: 397
Url:onsaveinstancestate-onrestoreinstancestate-basic-android-example

AD

Okhelp.cz