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);

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Motorola Droid X | motorola-droid-x

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Spokojenost uživatelů nadprůměrná.
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Motorola Droid X je (22.února2012) 8. nejpoužívanějším chytrým telefonem u programu Sky Map viz tabulka.

Android 2.1
Display 854 x 480 pixelů
8 megapixel fotoaparát dual LED flash
720p HD video recording
Music and Video player
8 GB paměť
rozšíření paměti 32 GB
WiFi/DLNA
TI OMAP3630 processor – 1GHz
4.3-inch large display

Motorola Droid X photo pic image

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238

Admob ads not visible on emulator Android 4.1 | admob-ads-not-visible-on-emulator-android-4-1

If you using GoogleAdMobAdsSdk-4.0.4.jar in your project and set android:targetSdkVersion="17" in AndroidManifest.xml , ads will not visible on emulator with Android 4.0.3 or 4.1.
You have to set as android:targetSdkVersion="17"


<uses-sdk android:minSdkVersion="4" 
        android:targetSdkVersion="17" />

Update project.properties file - row with target to 17:


# Project target.
target=android-17

Scroll to certain position on application Android example code | scroll-to-certain-position-on-application-android-example-code

ScrollTo(), getTop(), getBottom(), getLeft(), getRight(), ScrollView, LinearLayout Android Java xml example.
How get position of a View.
MainClass.java


/*
public void scrollTo (int x, int y) 
Since: API Level 1 
Set the scrolled position of your view. This will cause a call to onScrollChanged(int, int, int, int) and the view will be invalidated. 

This version also clamps the scrolling to the bounds of our child.

Parameters
x  the x position to scroll to 
y  the y position to scroll to  
  */

// sroll to top of hscrollViewMain
ScrollView hscrollViewMain = (ScrollView)findViewById(R.id.scrollViewMain);
hscrollViewMain.scrollTo(0, 0); // scroll to application top

// get position of a View
EditText hEdit = (EditText)findViewById(R.id.username_edit);
int nY_Pos = hEdit.getTop(); // getBottom(); X_pos  getLeft(); getRight();
// scroll to top of hEdit
hscrollViewMain.scrollTo(0,nY_Pos);

main.xml



<LinearLayout
    xmlns:android="//schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content">
    <ScrollView
        android:id="@*id/scrollViewMain"
        android:layout_width="fill_parent"
        android:layout_height="0dip"
        android:layout_weight="1">
        <LinearLayout
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:orientation="vertical"
            android:paddingTop="5dip"
            android:paddingBottom="13dip"
            android:paddingLeft="20dip"
            android:paddingRight="20dip">
            <TextView
                android:id="@+id/message"
                android:textAppearance="?android:attr/textAppearanceSmall"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginBottom="5dip" />
            <TextView
                android:textAppearance="?android:attr/textAppearanceSmall"
                android:textStyle="bold"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="@string/login_activity_username_label" />
            <EditText
                android:id="@+id/username_edit"
                android:singleLine="true"
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:minWidth="250dip"
                android:scrollHorizontally="true"
                android:capitalize="none"
                android:autoText="false"
                android:inputType="textEmailAddress" />
        </LinearLayout>
    </ScrollView>

</LinearLayout>

Date time difference determine which is earlier Android Java example | date-time-difference-between-two-dates

Date difference in millisecond between two date, GregorianCalendar, Calendar, after(), befor(), getTimeInMillis().



public class HoriziontalScrollActivity 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();
        Calendar firstDate = new GregorianCalendar(2011, Calendar.DECEMBER, 31);
        Calendar secondDate = new GregorianCalendar(2012, Calendar.JANUARY, 1);

        
        Boolean bDetermine = firstDate.after(secondDate);            // false
        strBuild.append("Is firsDate after secondDate? " + bDetermine + "

");
        bDetermine = firstDate.before(secondDate);                   // true
        strBuild.append("Is firsDate before secondDate? " + bDetermine + "

");
        
        
        long differenceInMillisecond = 0L;
         differenceInMillisecond = secondDate.getTimeInMillis()-firstDate.getTimeInMillis();
         // second == 1000 millisecond
         long second = differenceInMillisecond / 1000L;
         strBuild.append("Difference between two dates is: " + second + "

");
        
         txtV.setText(strBuild);

    }
  
}

TableRow TableLayout table row add delete remove removeview addview Android example | tablerow-tablelayout-table-row-add-delete-remove-removeview-addview-android-example

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>

Editace: 2011-09-26 20:49:50
Počet článků v kategorii: 396
Url:float-in-java-example-code