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Difference between “@+id/” and “@id/” in Android


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Difference between "@+id/” and "@id/” in Android
android:id="@+id/xxx" unique identifier of view
@id/ a reference to the unique identifier

 <TextView
        android:id="@+id/first_element_id"
        .........
 />
    <TextView
        android:id="@+id/second_element_id"
        android:layout_below="@id/first_element_id"
        ..........
 />


397LW NO topic_id




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Další témata ....(Topics)


303

WebView.loadData utf-8 encoding Android | webview-loaddata-utf-8-encoding-android


Try this solution:

String DATA = "Html text....bla bla bla. Hellou world!  čšřžěéá";
String HEADERHTML = 
"<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">" 
+"<html>  <head>  <meta http-equiv=\"content-type\" content=\"text/html; charset=utf-8\">"  
+"</head>  <body>";
String FOOTERHTML = "</body></html>";
WebView mWebView.loadData(HEADERHTML+DATA+FOOTERHTML,"text/html; charset=UTF-8",null);

206

at java.util.Arrays$ArrayList.get(Arrays.java:75) | at-java-util-arraysarraylist-getarrays-java75


Problem in Android application:

E/AndroidRuntime(416): FATAL EXCEPTION: main
E/AndroidRuntime(416): java.lang.IndexOutOfBoundsException
E/AndroidRuntime(416): 	at java.util.Arrays$ArrayList.get(Arrays.java:75)
E/AndroidRuntime(416): 	at android.widget.ArrayAdapter.getItem(ArrayAdapter.java:298)
E/AndroidRuntime(416): 	at android.widget.ArrayAdapter.createViewFromResource(ArrayAdapter.java:351)
E/AndroidRuntime(416): 	at android.widget.ArrayAdapter.getView(ArrayAdapter.java:323)
E/AndroidRuntime(416): 	at android.widget.Spinner.makeAndAddView(Spinner.java:192)
E/AndroidRuntime(416): 	at android.widget.Spinner.layout(Spinner.java:151)
E/AndroidRuntime(416): 	at android.widget.Spinner.onLayout(Spinner.java:115)


Solution: check code for set and get selection

// Spinner _spin1 contain only  49 items 
// you can set max 48 ( range 0 - 48)
// 50 is IndexOutOfBoundsException
_spin1.setSelection(50);
17

double in Java example for Android development | double-in-java-example-for-android-development


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);


211

The container JRE System Library JavaSE references non existing library | the-container-jre-system-library-javase-references-non-existing-library


Eclipse Error: The container JRE System Library JavaSE references non existing library QTJava.zip

Workaround:
Windows->Preferences->Java->Installed JRE
Press Add and select your JRE folder path for example:
c:\Program Files\Java\jre7\
and check your choice.

eclipse instaled jres path dialog
88

Map TreeMap key value pair sort by value Java Android example | map-treemap-key-value-pair-sort-by-value-java-android-example


Map TreeMap sorted by value Java Android example.

MainClass.java


import java.util.Comparator;
import java.util.Map;
import java.util.Map.Entry;
import java.util.SortedSet;
import java.util.TreeMap;
import java.util.TreeSet;

public class MainClass {
	public static void main(String[] arg) {

		// english;germany dictionary
		String[] arrayOfString = { "one;eine", "two;zwei", "three;drei",
				"four;vier" };

		Map<String, String> map = new TreeMap<String, String>();

		for (String s : arrayOfString) {
			String[] array = s.split(";");
			String sKey = "", sValue = "";
			if (array.length > 1) {
				sKey = array[0];
				sValue = array[1];
				map.put(sKey, sValue);
			}
		}
		for (Entry<String, String> entry: mapSortedByValues(map)) {
		    System.out.println(entry.getKey() + " = " + entry.getValue());
		}
	}

	static <K, V extends Comparable<? super V>> SortedSet<Map.Entry<K, V>> mapSortedByValues(
			Map<K, V> map) {
		SortedSet<Map.Entry<K, V>> sortedSetOfEntries = new TreeSet<Map.Entry<K, V>>(
				new Comparator<Map.Entry<K, V>>() {
					@Override
					public int compare(Map.Entry<K, V> entry_1, Map.Entry<K, V> entry_2) {
						int res = entry_1.getValue().compareTo(entry_2.getValue());
						return res != 0 ? res : 1; 
						// return entry_1.getValue().compareTo(entry_2.getValue());							
					}
				});
		sortedSetOfEntries.addAll(map.entrySet());
		return sortedSetOfEntries;
	}
}
/*
three = drei
one = eine
four = vier
two = zwei
 */



Editace: 2015-12-01 11:31:06
Počet článků v kategorii: 397
Url:difference-between-id-and-id-in-android

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