Play Sound Android Example

RectF, drawRoundRect(),

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) {
			Paint paint = new Paint();
			
			canvas.drawColor(Color.GREEN);
            
           Bitmap b = Bitmap.createBitmap(200, 200, Bitmap.Config.ALPHA_8);
           Canvas c = new Canvas(b);
           RectF rectF = new RectF();
           rectF.set(5,5,150,150);
           c.drawRoundRect(rectF, 10, 10, paint);
           
            paint.setColor(Color.RED);
           
           canvas.drawBitmap(b, 10,10, paint);
		}

	}
}

TableRow TableLayout table row add delete remove removeview addview get table row index indexOfChild create table row dynamically TextView dynamically Android example
Main.java

TableLayout table = (TableLayout)findViewById(R.id.table);
TableRow row = (TableRow)findViewById(R.id.row);

// get table row index android.
int nIndex = table.indexOfChild(row);
table.removeView(row); // invisible and height == 0
// add row into same place 
table.addView(row, nIndex); // visible

// add row into certain position
table.addView(row, 3); // visible

// create new TableRow dynamically 
TableRow tr = new TableRow(this);
         tr.setLayoutParams(new LayoutParams(
                        LayoutParams.FILL_PARENT,
                        LayoutParams.WRAP_CONTENT));

// create own function for append TableRow
   private void appendRow(TableLayout table) {
        TableRow row = new TableRow(this);

        TextView hLabel = new TextView(this);
        hLabel.setText("Some text");
        hLabel.setPadding(3, 3, 3, 3);

        TextView hNextLabel = new TextView(this);
        hNextLabel.setText("Next text");
        hNextLabel.setPadding(3, 3, 3, 3);
        hNextLabel.setGravity(Gravity.RIGHT | Gravity.TOP);

        row.addView(hLabel, new TableRow.LayoutParams(1));
        row.addView(hNextLabel, new TableRow.LayoutParams());

        table.addView(row, new TableLayout.LayoutParams());
    }

main.xml ScrollView, TableLayout, TableRow, TextView Android xml layout example

<ScrollView xmlns:android="//schemas.android.com/apk/res/android"
            android:layout_width="fill_parent"
            android:layout_height="fill_parent">
    <TableLayout
                android:id="@+id/table"
                  android:layout_width="fill_parent"
                 android:layout_height="fill_parent">
        <TableRow>
            <TextView android:layout_width="wrap_content"
                      android:layout_height="wrap_content"
                      android:text="Row index 0"/>
        </TableRow>
        <TableRow android:id="@+id/row">
            <TextView android:layout_width="wrap_content"
                      android:layout_height="wrap_content"
                      android:text="Row index 1"/>
        </TableRow>
        <TableRow>
            <TextView android:layout_width="wrap_content"
                      android:layout_height="wrap_content"
                      android:text="Row index 2"/>
        </TableRow>
        <TableRow>
            <TextView android:layout_width="wrap_content"
                      android:layout_height="wrap_content"
                      android:text="Row index 3"/>
        </TableRow>
		</TableLayout>
</ScrollView>

Check

• is sett debug mode on device?


• enabled debugging over USB?


• is device right connected?


• have you downloaded and instaled drivers for your device on PC?


• For Windows //developer.android.com/sdk/win-usb.html


• try disconnect and connect USB cable


• try do restart Android Studio

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);

How add pair of strings to Hashtable, how get pair key value from Hashtable, how split string, basic Java Android example.

MainClass.java

import java.util.Enumeration;
import java.util.Hashtable;
public class MainClass {
	public static void main(String[] arg) {
		
		// english;germany dictionary
		String[] arrayOfString = { "one;eine", "two;zwei", "three;drei" };

	    Hashtable<String, String> hashTable = new Hashtable<String, String>();
	    for(String s: arrayOfString){
	    	String[] array = s.split(";");
	    	String sKey ="", sValue="";
	    	if(array.length > 1){
	    	sKey = array[0]; sValue = array[1];
	    		hashTable.put(sKey, sValue);
	    	}
	    }

	    Enumeration<String> enumer = hashTable.keys();
	    while (enumer.hasMoreElements()) {
	      String keyFromTable = (String) enumer.nextElement();
	      // get Returns the value to which the specified key is mapped, 
	      // or null if this map contains no mapping for the key
	      System.out.println(keyFromTable + " = " + hashTable.get(keyFromTable));
	    }       

	    
	}
}
/*
two = zwei
one = eine
three = drei
 */