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double in Java example for Android development


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Java double is 64 bit double precision type used when fractional
precision calculation is required.

Java double je datový typ (reálné číslo) o velikosti 64 bitů. Používá se například pro přesný výsledek po dělení za desetinnou tečkou. Pokud nepotřebuje tak veliké číslo použijte raději typ float, šetříte tím paměť mobilního telefonu.


		// declaration and assignment of value  type double
		double x = 18.41785;
		//print formated  value
		System.out.printf("The value of x is %.3f%n", x); // 18.418
                
                // declaring more variables in single statement
                double d1 = 12.4, d2 = 564.5, d3 = 14.589;

		// double range of value
		System.out.println(Double.MIN_VALUE); // 4.9E-324
		System.out.println(Double.MAX_VALUE); // 1.7976931348623157E308

		// is NaN  Not-a-Number
		double f = (double) Math.sqrt(-15);
		boolean bNaN = Double.isNaN(f);
		System.out.print(bNaN); // true
		
                // check if a string is a valid number in Java example
                // convert string to double Java example
		String sD = "12.8";
		double dParse = Double.parseDouble(sD);

	       // convert strings to numbers
	      String sDl = "15.48";
	      double dFromString = (Double.valueOf(sDl)).doubleValue();

// format double, float or long value to string
	DecimalFormat formatter = new DecimalFormat(".##");
	String s = formatter.format(-.5678);             // -0.57
// .###  -0.568
// .#### -0.5678
// .000000  -.567800

// -123.456
// .##  -123.46
// #.##  -123.46

// #E0  -.1E3
// ##E0  -1.2E2
//###E0  -123E0

// double to string in Java example code
Double dObj = new Double(68.5);
String str = dObj.toString();
// else 
Double dS = 11.6;
String sdouble = dS.toString();

// compare two double variables
	      Double dComp1 = 4.3;
	      if(dComp1.equals(4.3))
	  		System.out.print("true");

	// compares the two specified double values in Java example
	// int i =	compare(double d1, double d2);
	    int i =	Double.compare(11.5, 11.7); // -1 first < second
	    // 0 first == second
	    // 1 first > second
	    System.out.print(i);



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58

HorizontalScrollView ScrollView horizontal vertical Android xml example | horizontalscrollview-scrollview-horizontal-vertical-android-xml-example


HorizontalScrollView ScrollView LinearLayout horizontal vertical Android xml basic example and image.

[caption id="attachment_889" align="alignleft" width="200" caption="horizontal scrollview horizontalscrollview android"]horizontalscrollview-android[/caption]


<?xml version="1.0" encoding="utf-8"?>
<LinearLayout android:id="@+id/LinearLayout01"
	android:layout_width="fill_parent" android:layout_height="fill_parent"
	xmlns:android="//schemas.android.com/apk/res/android">

	// horizontal and vertical Scrollview
	<ScrollView android:id="@+id/ScrollView01"
		android:layout_height="135px" android:layout_width="wrap_content"
		android:scrollbars="horizontal|vertical">

		// HorizontalScrollview
		<HorizontalScrollView android:id="@+id/HorizontalScrollView01"
			android:layout_height="fill_parent" android:layout_width="wrap_content">

			<LinearLayout android:id="@+id/LinearLayout02"
				android:layout_width="wrap_content" android:orientation="vertical"
				android:layout_height="fill_parent">
				<LinearLayout android:orientation="horizontal"
					android:layout_width="fill_parent" android:layout_height="fill_parent"
					android:layout_weight="1">
					<TextView android:text="red" android:gravity="center_horizontal"
						android:background="#aa0000" android:layout_width="200px"
						android:layout_height="fill_parent" android:layout_weight="1" />
					<TextView android:text="green" android:gravity="center_horizontal"
						android:background="#00aa00" android:layout_width="200px"
						android:layout_height="fill_parent" android:layout_weight="1" />
					<TextView android:text="blue" android:gravity="center_horizontal"
						android:background="#0000aa" android:layout_width="200px"
						android:layout_height="fill_parent" android:layout_weight="1" />
					<TextView android:text="yellow" android:gravity="center_horizontal"
						android:background="#aaaa00" android:layout_width="200px"
						android:layout_height="fill_parent" android:layout_weight="1" />
				</LinearLayout>

				<LinearLayout android:orientation="vertical"
					android:layout_width="fill_parent" android:layout_height="fill_parent"
					android:layout_weight="1">
					<TextView android:text="row one" android:textSize="15pt"
						android:layout_width="fill_parent" android:layout_height="wrap_content"
						android:layout_weight="1" />
					<TextView android:text="row two" android:textSize="15pt"
						android:layout_width="fill_parent" android:layout_height="wrap_content"
						android:layout_weight="1" />
					<TextView android:text="row three" android:textSize="15pt"
						android:layout_width="fill_parent" android:layout_height="wrap_content"
						android:layout_weight="1" />
					<TextView android:text="row four" android:textSize="15pt"
						android:layout_width="fill_parent" android:layout_height="wrap_content"
						android:layout_weight="1" />
				</LinearLayout>


			</LinearLayout>
		</HorizontalScrollView>
	</ScrollView>
</LinearLayout>



Other sample


<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="//schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:id="@+id/layout"
    android:orientation="vertical" >

    <HorizontalScrollView
        android:id="@+id/horizontalScrollView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" >

        <LinearLayout
            android:id="@+id/linearLayout1"
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"
            android:orientation="horizontal" >
        <TextView
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:text="Hello world! First TextView" />

        <TextView
            android:id="@+id/textView1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Large Text"
            android:textAppearance="?android:attr/textAppearanceLarge" />

        <TextView
            android:id="@+id/textView2"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Medium Text"
            android:textAppearance="?android:attr/textAppearanceMedium" />

        </LinearLayout>



    </HorizontalScrollView>

</LinearLayout>

167

INSTALL_FAILED_INSUFFICIENT_STORAGE | install_failed_insufficient_storage


1.) Try reopen the Emulaor and restart Eclipse.
OR
2.) Try to delete AVD from Eclipse menu Window - AVD manager.
OR
3.) Insert into manifest.xml this source code.

 <manifest xmlns:android="//schemas.android.com/apk/res/android"
    package="com.myweb.mypackage"
    android:installLocation="preferExternal"
254

Spinner Text Size Android Example | spinner-text-size-android-example



      Spinner  _spin1 = (Spinner) findViewById(R.id.spinLangFirst);
      ArrayAdapter<String> adapterJazyky = new ArrayAdapter<String>(this,
              R.layout.spinner_text_layout.xml, {"one","two","etc...."});
      adapterJazyky.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
      _spin1.setAdapter(adapterJazyky);





spinner_text_layout.xml

<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="//schemas.android.com/apk/res/android"
          android:id="@+id/spinnerText"
          android:layout_width="fill_parent"
          android:layout_height="wrap_content"
         
         android:textSize="20sp"
/>
346

Android Studio lock unlock file make read only or writable | android-studio-lock-unlock-file-make-read-only-or-writable


Select file in project explorer
Menu:
File - Make File Read-only - to lock
File - Make File Writable - to unlock

android-studio-lock-unlock-file.png
265

Whittled superscript sup tag TextView Android issue | whittled-superscript-sup-tag-textview-android-issue


Issue: Cropped superscript index between tags sup /sup is not correctly visible in TextView or View as Button.

String s = "10<sup>12 </sup>";
textView.setText(Html.fromHtml(s)); // 12 will cropped 
// solution:
s = "10<sup>12 </sup>\t	"; // add behind ending of sup tag the tabulator \t, 
// but not char \t but only press to TAB key!!! in source code
textView.setText(Html.fromHtml(s)); // 12 is visible correctly


textview-superscript-issue


Editace: 2011-09-26 20:49:42
Počet článků v kategorii: 397
Url:double-in-java-example-for-android-development

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