How to clear or hide an ImageView in Android

Get key by value from Map Java Android example


MainClass.java

import java.util.HashSet;
import java.util.Iterator;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
import java.util.TreeMap;

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

		// english;germany dictionary
		String[] arrayOfString = { "one;eine", "two;zwei", "two sets of;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);
			}
		}

		if (map.containsValue("zwei")) {
			Set<String> references = getKeysByValue(map, "zwei");
			 Iterator<String> it = references.iterator();
			    while (it.hasNext()) {
			      String key = (String) it.next();
			      String value = map.get(key);
			      System.out.println(key + " = " + value);
			    }
		}

	}

	public static <T, E> Set<T> getKeysByValue(Map<T, E> map, E value) {
		Set<T> keys = new HashSet<T>();
		for (Entry<T, E> entry : map.entrySet()) {
			if (entry.getValue().equals(value)) {
				keys.add(entry.getKey());
			}
		}
		return keys;
	}
}
/*
two = zwei
two sets of = zwei
 */

Insert into your default start up activity tag inten-filter tag with action MAIN and category LAUNCHER

            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="//schemas.android.com/apk/res/android"
    package="com.example.blabol"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="19" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name=".MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

If a button have focus, marquee will run.
Important:
android:singleLine="true"
android:ellipsize="marquee"
Optional:
android:marqueeRepeatLimit="1"

// main.xml
    <Button
        android:layout_width="150dip" 
        android:layout_height="wrap_content"
        android:text="My button with a long text for marquee as a example source code"
        android:singleLine="true"
        android:ellipsize="marquee"
        android:marqueeRepeatLimit="1"/>

If on Android emulator home button pressed.

// button home presssed
19:37:06.727: INFO/ActivityManager(60): Starting: 
Intent { act=android.intent.action.MAIN cat=[android.intent.category.HOME] 
flg=0x10200000 cmp=com.android.launcher/com.android.launcher2.Launcher } from pid 60

19:37:06.807: INFO/onSaveInstanceState(339): onSaveInstanceState()
19:37:06.848: INFO/onPause(339): onPause()
19:37:07.968: INFO/onStop(339): onStop()

Diagram of Activity lifecycle if button HOME pressed

Check your xml files in Eclipse Graphical Editor and fix problems.



Check project setup, right click on project, select properties, Java build path and
select correct Android version etc.


Right click on project, Android Tools, Fix Project Properties

Menu Eclipse select Project ->Clean.