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Draw color line set stroke width Android basic example


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Canvas, drawLine(), setStrokeWidth(), Paint, setAntiAlias(boolean), onDraw()

public class MainActivity extends Activity {
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(new SampleView(this));
	}

	private static class SampleView extends View {

		// CONSTRUCTOR
		public SampleView(Context context) {
			super(context);
			setFocusable(true);

		}

		@Override
		protected void onDraw(Canvas canvas) {

			canvas.drawColor(Color.YELLOW);
			Paint p = new Paint();
			// smooths
			p.setAntiAlias(true);
			p.setColor(Color.RED);
			p.setStrokeWidth(4.5f);
			// opacity
			p.setAlpha(0x80); //
			// drawLine (float startX, float startY, float stopX, float stopY,
			// Paint paint)
			canvas.drawLine(0, 0, 40, 40, p);
			canvas.drawLine(40, 0, 0, 40, p);

		}

	}
}

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64

Leap year date time Java Android example | leap-year-date-time-java-android-example


GregorianCalendar cal = new GregorianCalendar(); Boolean b = cal.isLeapYear(2012); // true, Android example.



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;
        StringBuilder strBuild = new StringBuilder();
        
         GregorianCalendar cal = new GregorianCalendar();
         Boolean b = cal.isLeapYear(2012); // true
         strBuild.append("Is leap year 2012? " + b + "

"); b = cal.isLeapYear(2014); // false strBuild.append("Is leap year 2014? " + b + "
"); txtV.setText(strBuild); } }
36

Titlebar title bar change text setTile Android example | titlebar-title-bar-change-text-android-example


Change the title associated with this activity. If this is a top-level activity, the title for its window will change. If it is an embedded activity, the parent can do whatever it wants with it.




 String sTitle = "My new title";
 setTitle(sTitle);



302

Layout not found on Android 2.1 | layout-not-found-on-android-2-1


If I create own folder layout-w320dp with Eclipse Android 4.4
layout was correctly loaded.
If I trying this application on tablet with Android 2.1 application crashed.


layout-not-loaded-android-2-1
262

Font Family change on View dynamically Android Example | font-family-change-on-view-android-example


TypeFace, setTypeface, font, font family, array of String, Button create dynamically

@Override
protected void onStart() {
LinearLayout.LayoutParams p = new LinearLayout.LayoutParams(
  48,
  55
);	
Typeface typeFace = Typeface.MONOSPACE;	
String [] ar = {"A","B","C","D","E","F","G","H","J","K"};
for (int i = 0; i < ar.length; i++) {
Button buttonView = new Button(this);
buttonView.setText(Html.fromHtml("<b>"+ar[i]+"</b>"));
buttonView.setTextColor(Color.BLUE);
buttonView.setTextSize(27.f);
buttonView.setTypeface(typeFace,Typeface.BOLD);
buttonView.setOnClickListener(mThisButtonListener);
if(i%2==0)
	mLayoutButtons.addView(buttonView, p);
else
	mLayoutButtonsNextRow.addView(buttonView, p);
	
_listOfButtons.add(buttonView);
}

	super.onStart();
}

//////// xml file
<TextView
    android:id="@+id/text01"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:textSize="20dp"
    android:fontFamily="Arial"
 />
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.

 

 


Editace: 2013-12-09 13:11:39
Počet článků v kategorii: 397
Url:draw-line-android-basic-example

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