Draw circle Android basic example
Canvas, drawCircle(), Paint, onDraw(), 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.drawCircle(50, 50, 30, p);
}
}
}
396LW NO topic_id
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How set JAVA path to Environment Variables on Windows (7)
Select Start menu > Computer > System Properties > Advanced System Settings(properties).
Then open Advanced tab > Environment Variables and add a new system variable JAVA_HOME that points to your JDK folder, for example
Select Start menu > Computer > System Properties > Advanced System Settings(properties).
Then open Advanced tab > Environment Variables and add a new system variable JAVA_HOME that points to your JDK folder, for example
C:\Program Files\Java\jdk1.8.0_05
Drawable dr = getResources().getDrawable(R.drawable.algebra);
int h = dr.getIntrinsicHeight();
int w = dr.getIntrinsicWidth();
Bitmap ball = BitmapFactory.decodeResource(getResources(), R.drawable.algebra);
int _nWidth = ball.getWidth();
int _nHeight = ball.getHeight();
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.
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);
// warning
private static String DB_PATH = "/data/data/cz.okhelp.german_czech_phrases/databases/";
// OK
public DataBaseHelper(Context context) {
super(context, DB_NAME, null, 1);
this.myContext = context;
// OK
DB_PATH = context.getFilesDir().getParentFile().getPath()
+ "/databases/";
}
This software allow find all IDs from xml layout file source code and create variables with findViewById for onCreate, for onClick and load save preferences functions.
Get all ID is for Windows XP and higher.
2017,04,28
Download 1.0.2.0
[caption id="attachment_903" align="alignleft" width="300" caption="Get all ID from xml file for Android developers utility."][/caption]
Get all ID is for Windows XP and higher.
2017,04,28
Download 1.0.2.0
[caption id="attachment_903" align="alignleft" width="300" caption="Get all ID from xml file for Android developers utility."][/caption]
Editace: 2013-12-09 13:11:26
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Url:draw-circle-android-basic-example