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Draw Oval Android basic example


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drawOval(), setStrokeWidth(), setStyle()


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.CYAN);
			Paint p = new Paint();
			// smooths
			p.setAntiAlias(true);
			p.setColor(Color.RED);
			p.setStyle(Paint.Style.STROKE); 
			p.setStrokeWidth(4.5f);
			// opacity
			//p.setAlpha(0x80); //
 
			canvas.drawOval(new RectF(50, 50, 20, 40), p);;
		}

	}
}

397LW NO topic_id




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Další témata ....(Topics)


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Call requires permission which may be rejected by user | call-requires-permission-which-may-be-rejected-by-user


Call requires permission which may be rejected by user: code should explicitly check to see if permission is available (with `checkPermission`) or explicitly handle a potential `SecurityException`




try {
// your code for example: 
//  LocationManager locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);         
//  Criteria criteria = new Criteria();
//        provider = locationManager.getBestProvider(criteria, false);
//  locationManager.requestLocationUpdates(provider, 400, 1, this);
        } catch (SecurityException e) {
            e.printStackTrace();
        }


270

How to Add Home Screen Widgets on Your Android Phone | how-to-add-home-screen-widgets-on-your-android-phone


Long press by finger on screen
From dialogue select Widgets
Select your widget
Put your widget on the screen

Video tutorial - to add home screen widgets - Android 2.1

39

How setup color coloring syntax code highlight highlighting in Eclipse editor Android example | how-setup-color-syntax-highlight-in-eclipse-android-example


How setup color coloring highlight highlighting syntax font size and family in Eclipse Java and XML editor Android example
Java editor

  1. Go to Eclipse menu Window -> Preferences

  2. Doubleclick on Java

  3. Double click on Editor

  4. Select Java, Javadocs or Comments and setup color and font

  5. Font size and family change from Window->Preferences-> General->Appearance->Colors and Fonts


  6. Press OK for saving changes


xml editor
xml editor double click in Preferences dialog on xml -> Editor -> Syntax coloring
[caption id="attachment_627" align="alignleft" width="297" caption="Eclipse editor syntax color settings"]eclipse-color-syntax-highlight-settings[/caption]
232

goto statement in Java | goto-statement-in-java


You can use for, do while, while cycle for example:

public void myFunction(){
 for (int i = 0; i < 1; i++) {
	// some code
       int c = 10;
       if(c==10)
         break; // goto stop; in C++
 } // end of for
 // stop: // break moved process to end of for
 


 // next code

}


16

float in Java example code | float-in-java-example-code


Android development
Java float is 32 bit single precision type and used when fractional precision calculation is required.

Java float je 32 bitů veliké číslo sloužící především pro přesný výsledek za desetinnou tečkou například při dělení čísel. Pro větší přesnost použíijte 64 bitový typ Double.


		// declaration and assignment of value  type float
		float x = 18.41785f;
		//print formated  value
		System.out.printf("The value of x is %.3f%n", x); // 18.418
                
                // declaring more variables in single statement
                float f1 = 12.4F, f2 = 564.5F, f3 = 14.589F;

		// float range of value
		System.out.println(Float.MIN_VALUE); // 4E-45
		System.out.println(Float.MAX_VALUE); // 4028235E38

		// is NaN  Not-a-Number
		float f = (float) Math.sqrt(-15);
		boolean bNaN = Float.isNaN(f);
		System.out.print(bNaN); // true
		
                // check if a string is a valid number in Java example
                // convert string to float Java example
		String sF = "12.8";
		float fParse = Float.parseFloat(sF);

	       // convert strings to numbers
	      String sFl = "15.48";
	      float fFromString = (Float.valueOf(sFl)).floatValue();

// float to string in Java example code
Float fObj = new Float(68.5);
String str = fObj.toString();
// else 
Float fS = 11.6f;
String sFloat = fS.toString();

              // compare two float variables
	      Float fComp1 = 4.3f;
	      if(fComp1.equals(4.3f))
	  		System.out.print("true");

	    // compares the two specified float values in Java example
	    int i =	Float.compare(11.5f, 11.7f); // -1 first < second
	    // 0 first == second
	    // 1 first > second
	    System.out.print(i);




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

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