Convert Activity to Fragment Step by Step

public class Main extends Activity {

private TextView mTextView;
private Activity mAct;
private Intent mIntent;

protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.main_layout);
  mTextView = findViewById(R.id.mTextView);
  mAct = getActivity();
  mIntent = getIntent();
 }

}

to:

public class Main extends Fragment{

 private TextView mTextView;
 private FragmentActivity mFrgAct;
 private Intent mIntent;
 private LinearLayout mLinearLayout;
 public View onCreateView(LayoutInflater inflater, ViewGroup container,
          Bundle savedInstanceState) {
          View root = inflater.inflate(R.layout.fragment_main, null);
        return root;
    }

 public void onViewCreated(View view, Bundle savedInstanceState) {
          // you can add listener of elements here
          /*Button mButton = (Button) view.findViewById(R.id.button);
            mButton.setOnClickListener(this); */
          mTextView = view.findViewById(R.id.mTextView);
          mLinearLayout = (LinearLayout)view;
 }
 public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
          mFrgAct = getActivity();
          mIntent = mFrgAct.getIntent(); //  Intent intent = new Intent(getActivity().getIntent());
 }

}

396LW NO topic_id

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Random number Java | random-number-java

Generate random number Android Java example source code.

		Random rand = new Random();
		int i = rand.nextInt() % 256; // range -255  +255
		System.out.print(i + "

"); // -184
		i = Math.abs(rand.nextInt() % 12); // range 0  +11
		System.out.print(i); // 7


// Math.random() start with 0.  e.g. 0.35981234 
int nRan = (int) (Math.random()*10); // 0 - 10

// nextDouble(), nextFloat(), nextInt(), nextLong() returns 0 - 10
import java.util.Random;´

Random r = new Random();
int nRan = r.nextInt(); // 0 - 10
double dRan = r.nextDouble() * 10; // e.g. 7.496285271597397

nextDouble – return 0 - 1
nextFloat – same as double
nextInt –  -2147483648  +2147483647
nextLong –  -922337203685775808  +9223372036854775807
nextGaussian –  0.0 aberation 1.0.

Screen Android Landscape Portrait programmatically | screen-android

Screen Android example source code for developers.
Get orientation of screen.


 public int getScreenOrientation() {
  if (getResources().getConfiguration().orientation == Configuration.ORIENTATION_PORTRAIT)                {
       return 1; // Portrait Mode
   
  }else if (getResources().getConfiguration().orientation == Configuration.ORIENTATION_LANDSCAPE) {
       return 2;   // Landscape mode
  }
  return 0;
 }

203

java.lang.NullPointerException: println needs a message | java-lang-nullpointerexception-println-needs-a-message

Problemi is in e.getMessage() what can return null and Log.e (String tag, String msg) will throws an new exception !!!!
Problem and solution:


      	try {
      		int [] i = {1};
      		int z = i[5];
      	} catch (ArrayIndexOutOfBoundsException e) {
      		String s = e.toString(); // s == java.lang.ArrayIndexOutOfBoundsException
                // try to testing String s for null value
      		if(s != null)
      		 Log.e("bla", s);
      		else 
      		 Log.e("bla", "My error text 1");
      		
      		String s2 = e.getMessage(); // s2 == null !!!!!!!
                // you need to testing String s2 for null value , or you get FATAL EXCEPTION: main
                // and application will be crashed
       		String s2 = e.getMessage(); // s2 == null !!!!!!!
      		if(s2 != null)
      		 Log.e("bla2", e.getMessage());
      		else 
      		 Log.e("bla2", "My error text 2");
     		
                // this is OK
      		e.printStackTrace();
      	}

LogCat:


E/bla(855): java.lang.ArrayIndexOutOfBoundsException

 E/bla2(855): My error text 2

 W/System.err(855): java.lang.ArrayIndexOutOfBoundsException
 W/System.err(855): 	at cz.okhelp.motion._MotionActivity.onTouchEvent(_MotionActivity.java:54)
 W/System.err(855): 	at android.app.Activity.dispatchTouchEvent(Activity.java:2099)
 W/System.err(855): 	at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:1675)
 W/System.err(855): 	at android.view.ViewRoot.deliverPointerEvent(ViewRoot.java:2194)
 W/System.err(855): 	at android.view.ViewRoot.handleMessage(ViewRoot.java:1878)
 W/System.err(855): 	at android.os.Handler.dispatchMessage(Handler.java:99)
 W/System.err(855): 	at android.os.Looper.loop(Looper.java:123)
 W/System.err(855): 	at android.app.ActivityThread.main(ActivityThread.java:3683)
 W/System.err(855): 	at java.lang.reflect.Method.invokeNative(Native Method)
 W/System.err(855): 	at java.lang.reflect.Method.invoke(Method.java:507)
 W/System.err(855): 	at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
 W/System.err(855): 	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
 W/System.err(855): 	at dalvik.system.NativeStart.main(Native Method)

Or you can using this code:


      	try {
      		int [] i = {1};
      		int z = i[5];
      	} catch (Exception e) {
      		
      		
      		StringBuilder sb = new  StringBuilder().append(e.getClass().getSimpleName()); 
          if  (e.getMessage() != null) { 
              sb.append("

"); 
              sb.append(e.getMessage()); 
          } 
          Log.e("err", sb.toString()); // E/err(336): ArrayIndexOutOfBoundsException

          // this code write out all message
          Log.e("myError", "methodName", e);
       }
// E/myError(371): methodName
// E/myError(371): java.lang.ArrayIndexOutOfBoundsException
// E/myError(371): 	at cz.okhelp.motion._MotionActivity.onTouchEvent(_MotionActivity.java:54)
// E/myError(371): 	at android.app.Activity.dispatchTouchEvent(Activity.java:2099)
// E/myError(371): 	at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:1675)
// E/myError(371): 	at android.view.ViewRoot.deliverPointerEvent(ViewRoot.java:2194)
// E/myError(371): 	at android.view.ViewRoot.handleMessage(ViewRoot.java:1878)
// E/myError(371): 	at android.os.Handler.dispatchMessage(Handler.java:99)
// E/myError(371): 	at android.os.Looper.loop(Looper.java:123)
// E/myError(371): 	at android.app.ActivityThread.main(ActivityThread.java:3683)
// E/myError(371): 	at java.lang.reflect.Method.invokeNative(Native Method)
// E/myError(371): 	at java.lang.reflect.Method.invoke(Method.java:507)
// E/myError(371): 	at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
// E/myError(371): 	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
// E/myError(371): 	at dalvik.system.NativeStart.main(Native Method)

130

Bitmap get Bitmap from resource Android example | bitmap-get-bitmap-from-resource-android-example

PNG, GIF, BMP, JPG


// //www.apache.org/licenses/LICENSE-2.0

// 1.)  Bitmap from stream
            InputStream is = context.getResources().openRawResource(R.drawable.my_image);
            mBitmap = BitmapFactory.decodeStream(is);
           

// 2.) 
            Bitmap ball = BitmapFactory.decodeResource(getResources(), R.drawable.ball);
            int dstWidth =120;
            int dstHeight = 120;
            mBitmap = Bitmap.createScaledBitmap(ball, dstWidth, dstHeight, true);

// 3.)
Bitmap  mBitmap = Bitmap.createBitmap(320, 480, Bitmap.Config.ARGB_8888);


        Bitmap  mBitmap;
        Canvas  mCanvas;
        Paint   mBitmapPaint;
            
            mBitmap = Bitmap.createBitmap(320, 480, Bitmap.Config.ARGB_8888);
            mCanvas = new Canvas(mBitmap);
            mBitmapPaint = new Paint(Paint.DITHER_FLAG);

// 4.)
          Bitmap  mBitmap = Bitmap.createBitmap(w, h, Bitmap.Config.RGB_565);
          Canvas  mCanvas.setBitmap(mBitmap);
            mCanvas.drawColor(0xFFFFFFFF);

Map TreeMap key value pair sort by key, using of iterator Java Android example | map-treemap-key-value-pair-sort-by-key-using-of-iterator-java-android-example

Map TreeMap key value pair, Map sort by key, Iterator for Map Java Android example.

MainClass.java


import java.util.ArrayList;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
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", "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);
	    	}
	    }
		List sortedByKeys=new ArrayList(map.keySet());
		Collections.sort(sortedByKeys);
		
            // iterate map
	    Set references = map.keySet();
	    Iterator it = references.iterator();
	    while (it.hasNext()) {
	      String key = (String) it.next();
	      String value = map.get(key);
	      System.out.println(key + " = " + value);
	    }
            // or other example how iterate map
	    TreeSet<String> keys = new TreeSet<String>(map.keySet());
	    for (String key : keys) { 
	       String value = map.get(key);
	       System.out.println(key + " = " + value);
	       
	    }		


		
       // check if key exists 	    
//	   if( map.containsKey("two")){
//		System.out.print("two = " + map.get("two"));
//	   }
	}
}
/*
four = vier
one = eine
three = drei
two = zwei
 */

Editace: 2017-02-04 17:50:34
Počet článků v kategorii: 396
Url:convert-activity-to-fragment-step-by-step