Web Technology Experts Notes

Android Interview Questions and Answers for fresher and Experienced

Question: What is Android?
Android an open-source operating system used for smartphones and tablet.

Question: How to start anroid development?
1. Download Android Studio.
2. Download the latest SDK tools and platforms.
3. Create a Project(Application) with Android Studio.
4. Now Running Your Application.
5. Install an editor for development (I am using eclipse editor for development).

Question: What main components of Android application?
1. Activities: They dictate the UI and handle the user interaction to the screen.
2. Services: They handle background processing associated with an application.
3. Broadcast Receivers: They handle communication between Android OS and applications.v 4. Content Providers: They handle data and database management stuff.

Question: What is Intent? What are two different type of Intent?
Intent means "intention" to do an action.
Question: Difference between px, sp, dip, dpi and pt in Android?
px is one pixel. px is corresponds to actual pixels on the screen.
sp is scale-independent pixels. SP is like the dp unit, but it is also scaled by the user's font size preference.
dip is Density-independent pixels.
dpi is Dots per inches.
pt is points.

Question: How to Close/hide the Android Soft Keyboard?
Hide the virtual keyboard using the InputMethodManager.

Question: How to Lazy load of images in ListView in Android?
You can use droidQuery.

$.with(myView).image(url);

Question: How to get unique Android device ID?

Settings.Secure#ANDROID_ID

Will return unique Android device ID.

Question: How to get screen dimensions in pixels in Andorid Devices?

int screenHeight = getResources().getDisplayMetrics().heightPixels;
int screenWidth = getResources().getDisplayMetrics().widthPixels;

Question: How do I center text horizontally and vertically in a TextView in Android?

<textview android:gravity="center" android:layout_height="fill_parent" android:layout_width="fill_parent" android:text="@string/username"></textview>

Question:What is the difference between match_parent and fill_parent?
Both are same thing and are different name in different API version.
match_parent means view should be as big as its parent (minus padding. This name is used in less than API Level 7.
fill_parent means view should be as big as its parent (minus padding). This constant is deprecated starting from API Level 8 and is replaced by match_parent.

Question: Is there a way to get the source code from an APK file?
http://stackoverflow.com/questions/3593420/is-there-a-way-to-get-the-source-code-from-an-apk-file

Question: How to set Standard Android Button with a different color?

button.getBackground().setColorFilter(new LightingColorFilter(0xFFFFFFFF, 0xFFAA0000));

Question: How to disable landscape mode in Android?
Open AndroidManifest.xml file and set following.

android:screenOrientation="sensorPortait"

Question: How can I open a URL in Android's web browser from my application?

Intent browserIntent = new Intent(Intent.ACTION_VIEW, Uri.parse("http://www.web-technology-experts-notes.in/2015/04/to-whom-does-pci-compliance-need-to-apply.html"));
startActivity(browserIntent);

Question: How do you install an APK file in the Android emulator?
http://stackoverflow.com/questions/3480201/how-do-you-install-an-apk-file-in-the-android-emulator

Question: How to Converting pixels to dp and vise versa?

public static float dpFromPx(final Context context, final float px) {
    return px / context.getResources().getDisplayMetrics().density;
}

Question: Can we display HTML in TextView? If yes, then How?
Yes, we can display HTML.

myTextView.setText(Html.fromHtml("<h2>
Web Technology</h2>
This is testing

"));

Question: How to put a border around an android textview?

<textview android:background="@drawable/back" android:text="Some text"></textview>

Question: To whom does PCI compliance need to apply? If I am only processing the Credit card detail, do i need still to apply for PCI Compliance?

If you are accept credit card/debit card on your website, you need PCI compliance.
If your customer is entering card/debit card on your website, you need PCI compliance.
Because you are processing the credit card, whether you are storing OR not, but you need PCI compliance.

Full form of PCI is Payment Card Industry Data Security Standards (PCI DSS).

Reading PCI Compliance.
Link 1: https://www.pcicomplianceguide.org/pci-faqs-2/#2
Search with : "To whom does PCI apply"

Link 2: https://developer.paypal.com/docs/integration/direct/accept-credit-cards/
Search with "All merchants who accept, store, transmit"

If you are using "embed code"/"mini browser"/"redirect to third party" where customer entered the credit card details (its not your website), means customer is not entering cc details on your website, then you don't need PCI Compliance.