**getApplicationContext()** Application context is associated with the Applicaition and will always be the same throughout the life cycle.

**getBasecontext()** should not be used, just use Context instead of it which is associated with the activity and could possible be destroyed when the activity is destroyed.

**getApplication()** is available to Activity and Services only. Although in current Android Activity and Service implementations, **getApplication()** and **getApplicationContext()** return the same object, there is no guarantee that this will always be the case (for example, in a specific vendor implementation).
So if you want the Application class you registered in the Manifest, you should never call **getApplicationContext()** and cast it to your application, because it may not be the application instance (which you obviously experienced with the test framework).

**getParent()** returns object of the activity if the current view is a child..In other words returns the activity object hosting the child view when called within the child. 

`getApplicationContext()` Application context is associated with the Application and will always be the same throughout the life cycle.


`getBasecontext()` should not be used, just use `Context` instead of it which is associated with the activity and can be destroyed when the activity is destroyed.

I want to display YouTube videos on my website, but I need to be able to add a unique `id` for each video that&#39;s going to be shared by users. So I put this together, and I have run into a little problem. I am trying to get the JavaScript to add a random string for the div `id`, but it&#39;s not working, showing the string:


    &lt;script type=&#39;text/javascript&#39; src=&#39;jwplayer.js&#39;&gt;&lt;/script&gt;
    &lt;script type=&#39;text/javascript&#39;&gt;
    function randomString(length) {
        var chars = &#39;0123456789ABCDEFGHIJKLMNOPQRSTUVWXTZabcdefghiklmnopqrstuvwxyz&#39;.split(&#39;&#39;);
        
        if (! length) {
            length = Math.floor(Math.random() * chars.length);
        }
        
        var str = &#39;&#39;;
        for (var i = 0; i &lt; length; i++) {
            str += chars[Math.floor(Math.random() * chars.length)];
        }
        return str;
    }
    
    var div = randomString(8);
    &lt;/script&gt;
    
    &lt;div id=&#39;div()&#39;&gt;This text will be replaced&lt;/div&gt;
    
    &lt;script type=&#39;text/javascript&#39;&gt;
      jwplayer(&#39;div()&#39;).setup({
        &#39;flashplayer&#39;: &#39;player.swf&#39;,
        &#39;file&#39;: &#39;http://www.youtube.com/watch?v=4AX0bi9GXXY&#39;,
        &#39;controlbar&#39;: &#39;bottom&#39;,
        &#39;width&#39;: &#39;470&#39;,
        &#39;height&#39;: &#39;320&#39;
      });
    &lt;/script&gt;

generate random string for div id

After upgrading to Mac OSX Lion I figured out that /etc/hosts is not looked up in first place for name resolution anymore. This leads to some side effects like:

 1. Entries in /etc/hosts are resolved painfully slow
 2. You can&#39;t not override existing domains, e.g. 127.0.0.1 www.google.com
 3. If you get search domain entries from DHCP, let say .lan, and some funny guy configured localhost.lan to something else then 127.0.0.1 in the local DNS you can not reach your localhost anymore.

Is this behavior intended? Does it make any sense? And most important, how can I come back to the old behavior.

Mac OSX Lion DNS lookup order

What is the difference between:

1. `getApplicationContext()`
2. `getBasecontext()`
3. `getApplication()`
4. `getParent()`

Can you elaborate with one simple example?  

getApplicationContext(), getBaseContext(), getApplication(), getParent()

<p>What is the difference between:</p>
<ol>
<li><code>getApplicationContext()</code></li>
<li><code>getBasecontext()</code></li>
<li><code>getApplication()</code></li>
<li><code>getParent()</code></li>
</ol>
<p>Can you elaborate with one simple example?</p>


Is there any way to make an Android application to download and use a Java library at runtime? 

Here is an example:

Imagine that the application needs to make some calculations depending on the input values. The application asks for these input values and then checks if the required `Classe`s or `Method`s are available. 

If not, it connects to a server, downloads the needed library, and loads it at runtime to calls the required methods using reflection techniques. The implementation could change depending on various criteria such as the user who is downloading the library.

Is it possible to dynamically load a library at runtime from an Android application?

I have created a custom widget, and I&#39;m declaring it in layout.xml.  I have also added some custom attributes in attr.xml.  However, when trying to declare these attributes in a style in styles.xml, it&#39;s giving me `No resource found that matches the given name: attr &#39;custom:attribute&#39;.`

I have put the `xmlns:custom=&quot;http://schemas.android.com/apk/res/com.my.package&quot;` in all of the tags in styles.xml, including `&lt;?xml&gt;`, `&lt;resources&gt;`, and `&lt;style&gt;`, but it still gives me the same error, that it can&#39;t find my custom XML namespace.

I can, however, use my namespace to manually assign attributes to the view in my layout.xml, so there is nothing wrong with the namespace.  My issue lies in making styles.xml aware of my attr.xml.

Custom attributes in styles.xml

I have a TextView which displays a long text. I want to give some space between lines like in CSS with line-height property. How can I do it?

Android TextView padding between lines

The problem occurs at 

    Element element = it.next();

And this code which contains that line, is inside of an `OnTouchEvent`

    for (Iterator&lt;Element&gt; it = mElements.iterator(); it.hasNext();){
		Element element = it.next();
		
		if(touchX &gt; element.mX  &amp;&amp; touchX &lt; element.mX + element.mBitmap.getWidth() &amp;&amp; touchY &gt; element.mY   
				&amp;&amp; touchY &lt; element.mY + element.mBitmap.getHeight()) {	 
			
			//irrelevant stuff..
			
			if(element.cFlag){
				mElements.add(new Element(&quot;crack&quot;,getResources(), (int)touchX,(int)touchY));
				element.cFlag = false;
			
			}			
		}
	}


All of this is inside `synchronized(mElements)`, where `mElements` is an `ArrayList&lt;Element&gt;` 

When I touch an `Element`, it may activate `cFlag`, which will create another `Element` with different properties, which will fall off the screen and destroy itself in less than a second. It&#39;s my way of creating particle effects. We can call this &quot;particle&quot; `crack`, like the String parameter in the constructor.



This all works fine until I add another main `Element`. Now I have two `Elements` on the screen at the same time, and if I touch the newest `Element`, it works fine, and launches the particles.

However, if I touch and activate `cFlag` on the older `Element`, then it gives me the exception.


   

     07-28 15:36:59.815: ERROR/AndroidRuntime(4026): FATAL EXCEPTION: main
    07-28 15:36:59.815: ERROR/AndroidRuntime(4026): java.util.ConcurrentModificationException
    07-28 15:36:59.815: ERROR/AndroidRuntime(4026):     at java.util.ArrayList$ArrayListIterator.next(ArrayList.java:573)
    07-28 15:36:59.815: ERROR/AndroidRuntime(4026):     at com.Juggle2.Panel.onTouchEvent(Panel.java:823)
    07-28 15:36:59.815: ERROR/AndroidRuntime(4026):     at android.view.View.dispatchTouchEvent(View.java:3766)
    07-28 15:36:59.815: ERROR/AndroidRuntime(4026):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:863)
    07-28 15:36:59.815: ERROR/AndroidRuntime(4026):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:863)
    07-28 15:36:59.815: ERROR/AndroidRuntime(4026):     at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:1767)
    07-28 15:36:59.815: ERROR/AndroidRuntime(4026):     at com.android.internal.policy.impl.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1119)
    07-28 15:36:59.815: ERROR/AndroidRuntime(4026):     at android.app.Activity.dispatchTouchEvent(Activity.java:2086)
    07-28 15:36:59.815: ERROR/AndroidRuntime(4026):     at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:1751)
    07-28 15:36:59.815: ERROR/AndroidRuntime(4026):     at android.view.ViewRoot.handleMessage(ViewRoot.java:1785)
    07-28 15:36:59.815: ERROR/AndroidRuntime(4026):     at android.os.Handler.dispatchMessage(Handler.java:99)
    07-28 15:36:59.815: ERROR/AndroidRuntime(4026):     at android.os.Looper.loop(Looper.java:123)
    07-28 15:36:59.815: ERROR/AndroidRuntime(4026):     at android.app.ActivityThread.main(ActivityThread.java:4627)
    07-28 15:36:59.815: ERROR/AndroidRuntime(4026):     at java.lang.reflect.Method.invokeNative(Native Method)
    07-28 15:36:59.815: ERROR/AndroidRuntime(4026):     at java.lang.reflect.Method.invoke(Method.java:521)
    07-28 15:36:59.815: ERROR/AndroidRuntime(4026):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:893)
    07-28 15:36:59.815: ERROR/AndroidRuntime(4026):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:651)
    07-28 15:36:59.815: ERROR/AndroidRuntime(4026):     at dalvik.system.NativeStart.main(Native Method)



How can I make this work?

Concurrent Modification Exception : adding to an ArrayList

I&#39;m having an odd problem.
I am making an app with targetsdk 13. 

In my main activity&#39;s onCreate method i call `getActionBar()` to setup my actionbar. This works fine when running on the Android 3.2 emulator, but when using Android 3.0 and 3.1 the `getActionBar()` method returns null.

I find this extremely odd, and i cannot see any reason why it would do so.
Is this a bug with the emulators or is there something i need to do, in order to ensure that my application has an actionbar? 

**SOLUTION:**
I think I&#39;ve found a solution for this problem.
I wasn&#39;t using the setContentView to set a layout for the activity. Instead I was using `fragmentTransaction.add(android.R.id.content, mFragment, mTag)` to add a fragment to the activity.
This worked fine in 3.2, but in earlier honeycomb versions the action bar is apparently not set if you don&#39;t use the setContentView in the `onCreate()` method.
So I fixed it by using the `setContentView()` method in my `onCreate()` method and just supplying it with a layout that contained an empty FrameLayout.
I can still use the `fragmentTransaction.add(android.R.id.content, mFragment, mTag)` method the same way as before.

It&#39;s not the prettiest fix, but it works. 

getActionBar() returns null

I would like to get the context of application which has reference/hosted my library at run-time inside one class of my library project. Is it possible? If yes, how?

Thanks

**Update**
I don&#39;t want my user to pass context in parameter to my library project because it is possible that my library project will be called through JNI and I have no idea how I can get context in JNI and pass it to Java layer.

Is it possible to get application&#39;s context in an Android Library Project?

There has been a lot of posting about what these two contexts are.. But I&#39;m still not getting it quite right

As I understand it so far:
Each is an instance of its class which means that some programmers recommend you to use `this.getApplicationContext()` as often as possible in order to not &quot;leak&quot; out any memory. This is because the other `this` (getting the `Activity` instance context) points to an `Activity` that is being destroyed each time the user tilts the phone or leave the app etc.. Which apparently the Garbage Collector (GC) doesn&#39;t catch and therefore uses too much memory.. 

But can anyone please come up with some really good coding examples where it would be the right thing to use `this` (getting the context of the current `Activity` instance) and the application context will be useless/wrong?

When to call activity context OR application context?

I am trying to use getResources method in a non-activity class. How do I get the reference to the &quot;resources&quot; object so that I can access the xml file stored under resources folder?

Example:

    XmlPullParser xpp = getResources().getXml(R.xml.samplexml);

Using getResources() in non-activity class

What does need to be imported or how can I call the Layout inflater in places other than activity?

    public static void method(Context context){
        //this doesn&#39;t work the getLayoutInflater method could not be found
        LayoutInflater inflater = getLayoutInflater();
        // this also doesn&#39;t work 
        LayoutInflater inflater = context.getLayoutInflater();
    }

I am able to call `getLayoutInflater` only in activity, is that an restriction? What if I want to create custom dialog and I want to inflate view for it, or what if I want to have Toast message with custom view that is shown from a service, I only have the context from the service I do not have any activity but I want to show custom message.

I need the inflater in places in the code that isn&#39;t in the activity class.

How can I do this ?



Call getLayoutInflater() in places not in activity

I need to get a Drawable object to display on an image button. Is there a way to use the code below (or something like it) to get an object from the android.R.drawable.* package?

for example if drawableId was android.R.drawable.ic_delete

    mContext.getResources().getDrawable(drawableId)



Content Type	Original Author	Original Content on Stackoverflow
Question	Nikunj Patel	View Question on Stackoverflow
Solution 1 - Android	Ravi	View Answer on Stackoverflow
Solution 2 - Android	Harinder	View Answer on Stackoverflow

getApplicationContext(), getBaseContext(), getApplication(), getParent()

Android Problem Overview

Android Solutions

Solution 1 - Android

Solution 2 - Android

Mac OSX Lion DNS lookup order

generate random string for div id

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