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Start Activity from list - launches other activities from list


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Activities launcher

public class MainActivity extends ListActivity {
    private class Sample {
        private CharSequence title;
        private Class<? extends Activity> activityClass;

        public Sample(int titleResId, Class<? extends Activity> activityClass) {
            this.activityClass = activityClass;
            this.title = getResources().getString(titleResId);
        }

        @Override
        public String toString() {
            return title.toString();
        }
    }

    private static Sample[] mSamples;

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // Instantiate the list of samples.
        mSamples = new Sample[]{
                new Sample(R.string.title_first_app, FirstActivity.class),
                new Sample(R.string.title_second_app, SecondActivity.class),
                new Sample(R.string.title_third_app, ThirdActivity.class),
        };

        setListAdapter(new ArrayAdapter<Sample>(this,
                android.R.layout.simple_list_item_1,
                android.R.id.text1,
                mSamples));
    }

    @Override
    protected void onListItemClick(ListView listView, View view, int position, long id) {
        // Launch the sample associated with this list position.
        startActivity(new Intent(MainActivity.this, mSamples[position].activityClass));
    }
}


397LW NO topic_id




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Další témata ....(Topics)


281

addPreferencesFromResource Deprecated Android Code Warning | addpreferencesfromresource-deprecated-android-code-warning


Put extends PreferenceFragment API level 11 instead PreferenceActivity

public class SettingsActivity extends PreferenceFragment {
  @Override
  public void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      addPreferencesFromResource(R.xml.preferences);
  }
}

// or insert suppresswarning
public class SettingsActivity extends PreferenceActivity {
  @SuppressWarnings("deprecation")
	@Override
  public void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      addPreferencesFromResource(R.xml.preferences);
  }
}

80

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.

MainClass.java

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)
		     arrayList.add(s);

		    Collections.sort(arrayList);
		    // foreach
		    for (String str: arrayList)
		      System.out.println(str);
		    
		    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
		    
		  }
}
/*
End
Hello
bye-bye
hello
nothing
people
world!
Min is: End
Max is: world!
Index of people is: 5
Index 5 is: people
*/
102

Unable to resolve id for attribute id Graphical layout editor Eclipse error | unable-to-resolve-id-for-attribute-id-graphical-layout-editor-eclipse-error


Problem: erroneous entry of id

<RadioButton android:id="idRadio"
                android:text="My radio button"/>


Solution: @+id/

<RadioButton android:id="@+id/idRadio"
                android:text="My radio button"/>
328

Screen size density independent pixel resolution | screen-size-density-independent-pixel-resolution


Terms Screen size, density, density independent pixel, resolution as a picture - pictogram.
mobile-phone-screen-resolution-terms

Test your knowledge
Q: How to find out the phone screen size?
A: (By length of display diagonale in inch -  Not to measure a diagonal of device!!!)

Q: What resolution has 720 x 1280 display?
A: (921600 pixels)

Q: What does it mean "240 dpi" screen density?
A: (Display have density 240 x 240  dots - "Tri-color LED etc." - per every physical (real) square inch. If you have icon 240x240 pixels, this will just occupy an area of one square inch on the display.)

Q: Phone have screen density 240 dpi. Image for 160 dpi screen density have size 128x 128 pixels. What will be the size of the image for 240 dpi screen density?
A: (Calculate the virtual pixels size.   128 * (240/160)  =  192.  You have to resize image to new size 192 x 192 physical pixels and put into folder drawable-hdpi (high) ~240dpi  for phone with screen density 240 dpi. ) or use density independend pixels 128dp x 128dp.

 

 
62

Date Calendar Java Android Example | date-calendar-java-android-example


Calendar cal = new GregorianCalendar(), int year = cal.get(Calendar.YEAR),
ERA, MONTH, DAY_OF_MONTH, DAY_OF_WEEK, Android example code.

public class MainActivity extends Activity {
TextView txtV;
	Context cntx;
	
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        txtV = (TextView)findViewById(R.id.idLabel);
        cntx = this;
        Calendar cal = new GregorianCalendar();

     int era = cal.get(Calendar.ERA);  // 0 B.C. before Christ, 1 Anno Domini              
     txtV.setText(txtV.getText() +"

" + era); int year = cal.get(Calendar.YEAR); // 2011 txtV.setText(txtV.getText() +"
" + year); int month = cal.get(Calendar.MONTH); // 0 is Januar txtV.setText(txtV.getText() +"
" + month); int day = cal.get(Calendar.DAY_OF_MONTH); // 1 to 31 txtV.setText(txtV.getText() +"
" + day); int dayOfWeek = cal.get(Calendar.DAY_OF_WEEK); // 1=Sunday, 2=Monday ... txtV.setText(txtV.getText() +"
" + dayOfWeek); } }


Editace: 2016-02-25 19:32:45
Počet článků v kategorii: 397
Url:start-activity-from-list-launches-other-activities-from-list

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