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Make an alert only appear when app is opened

Is there a way to make an alert only appear when the app is opened? I'm creating an alert in onStart() in my MainActivity and whenever I go back to that activity in the app, it shows the alert again which can be annoying to the user. Or is there a way to create a "got it" button and then turn off the alert? Here is my code:
protected void onStart() {
super.onStart();
new AlertDialog.Builder(this)
.setTitle("Instructions")
.setMessage("Hello! To begin, select a map from the list to train with. Make sure" +
" you are on the correct floor.")
.setPositiveButton(android.R.string.yes, new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
}
})
.setIcon(R.drawable.ic_launcher)
.show();
}

This is because when another activity comes to foreground upon your MainActivity makes your activity goes to OnPause().
Then when you go back to your MainActivity. The system calls
onStart() again. See The activity life cycle
-First Solution
public class TestActivity extends ActionBarActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (savedInstanceState == null) {
showAlertDialog();
}
}
private void showAlertDialog() {
// code to show alert dialog.
}
}
-Second Solution
public class TestActivity extends ActionBarActivity {
private static boolean isAlertDialogShownBefore = false;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (!isAlertDialogShownBefore) {
showAlertDialog();
isAlertDialogShownBefore = true;
}
}
private void showAlertDialog() {
// code to show alert dialog.
}
#Override
public void onBackPressed() {
isAlertDialogShownBefore = false;
super.onBackPressed();
}
}

Put that code in onCreate method of your activity. Check for saveInstanceState for null, if it is then show your alertDialog

How to enter two activity links in another activity?

I know my question might be stupid but I am new in Android App development and the Eclipse things but reached to e problem that can't find solution in internet.
I am making multi-activity application and reached to a point where when i have two buttons in one of the activities and want each of them to lead to different other activities, the application crashes. When I lead them both to one activity, everything is fine. Here is my code and hope really my question not to be so stupid as I am thinking.
public class Home extends ActionBarActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_home);
Button myButton = (Button) findViewById(R.id.tables);
myButton.setOnClickListener(goToTables);
Button mySecondButton = (Button) findViewById(R.id.reservations);
mySecondButton.setOnClickListener(goToMenu);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.home, menu);
return true;
}
private OnClickListener goToTables = new OnClickListener(){
#Override
public void onClick(View v) {
doButton();
}};
private void doButton()
{
startActivity(new Intent(this, Tables.class));
}
private OnClickListener goToMenu = new OnClickListener(){
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
doSecondButton();
}};
private void doSecondButton()
{
startActivity(new Intent(this, Menu.class));
}
}
The goToTables works perfectly but I am missing something important to change in goToMenu. My other activities are: Tables and Menu. Can somebody please tell me where I am wrong? Thanks in advance!

android:onClick="dobutton" try adding this in your button tag in xml code rather then using onclicklistner.

Try changing the name of your Menu activity or add the full name path of Menu.class in your intent, eg. com.myapp.Menu.class

Call function from Activity Class after preferences are updated Android

I would like to call a function from my main activity class after my preferences are updated, but I can't use onResume() because I have other classes that will trigger onResume (I believe).
Snippet from AndroidGPSTrackingActivity.java:
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.settings:
startActivity(new Intent(this, SettingsActivity.class));
break;
}
return false;
}
SettingsActivity.java:
package com.example.gpstracking;
import android.os.Bundle;
import android.preference.PreferenceActivity;
public class SettingsActivity extends PreferenceActivity {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
addPreferencesFromResource(R.xml.preferences);
}
}
After my preferences close, I want to call a function from my Main Activity, however it MUST be from my main activity because I need to send a context from my Main Activity. I've tried so much and just can't seem to get it.

onResume() is triggered when the Activity comes to the foreground. You should never be "triggering" onResume() other than leaving/returning to the Activity (if you're ever directly calling onResume(), you're doing it wrong).
Assuming you're needing to check for the updated value when you return to your Activity, then yes, onResume() is where you should probably do that. If the user returns to MainActivity after viewing SettingsActivity, then onResume() will be called, and you can check the updated preference value there.
EDIT: So I think honestly you'd be better off checking the preference values in onResume(), and not caching them globally. They aren't expensive to look up. Also, for immediate notifications, you could register a listener for preference changes, like so:
public class MainActivity extends Activity
implements SharedPreferences.OnSharedPreferenceChangeListener {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
registerPreferenceListener();
}
#Override
protected void onDestroy() {
super.onDestroy();
unregisterPreferenceListener();
}
private void registerPreferenceListener() {
PreferenceManager.getDefaultSharedPreferences(this)
.registerOnSharedPreferenceChangeListener(this);
}
private void unregisterPreferenceListener() {
PreferenceManager.getDefaultSharedPreferences(this)
.unregisterOnSharedPreferenceChangeListener(this);
}
#Override
public void onSharedPreferenceChanged(
SharedPreferences sharedPreferences, String key) {
if ("the_key_i'm_interested_in".equals(key)) {
// Update stuff
}
}
}

Is my activity being leaked - and is it the ActionBar that's doing it?

I have an Activity named PhotoSelectorActivity. It inherits from a BaseActivity that looks like this:
public class BaseActivity
extends ActionBarActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Log.d(this.getClass().getSimpleName(),
"onCreate("+Integer.toHexString(System.identityHashCode(this))+")");
}
#Override
protected void onDestroy() {
super.onDestroy();
getSupportActionBar().setCustomView(null);
Log.d(this.getClass().getSimpleName(),
"onDestroy("+Integer.toHexString(System.identityHashCode(this))+")");
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
return onNavigateUp(item);
case R.id.menu_item_settings:
startActivity(new Intent(this, PreferencesActivity.class));
return true;
default:
return super.onOptionsItemSelected(item);
}
}
#TargetApi(Build.VERSION_CODES.HONEYCOMB)
protected ActionBar setupActionBar(boolean enableBackButton) {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
getSupportActionBar().setDisplayHomeAsUpEnabled(enableBackButton);
}
ActionBar actionBar = getSupportActionBar();
actionBar.setCustomView(R.layout.action_bar);
actionBar.setDisplayShowTitleEnabled(false);
actionBar.setDisplayShowCustomEnabled(true);
return null;
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
}
The purpose of this BaseActivity is to provide the same menu and actionbar to each one of my activities. You'll notice the getSupportActionBar().setCustomView(null) in the onDestroy() method, that's there to try and combat the problem that I may be having.
When i get an orientation change event, i notice in DDMS that i end up with 2 instances of my activity. One of them may be leaking, but I'm not certain. Here's a screen shot from DDMS:
So the object at the top is the Activity in question: PhotoSelectorActivity. The instance shown here is the previous instance (onDestroy() has already been called on it). Yet it remains in memory even after a forced GC via DDMS.
Another bit of information is that this only seems to happen after using a dialog. That is, when the Activity is initially displayed and before the user performs and action I can do back to back orientation changes without the # of activities climbing above 1. After I've used the following dialog i seem to get the extra Activity in memory:
public class PhotoSourceDialog
extends DialogFragment
implements DialogInterface.OnClickListener {
public static interface PhotoSourceDialogListener {
void onPhotoSourceSelected(String result);
}
private PhotoSourceDialogListener listener;
#Override
public void onAttach(Activity activity) {
super.onAttach(activity);
if (!PhotoSourceDialogListener.class.isInstance(activity)) {
throw new IllegalStateException(
"Activity must implement PhotoSourceDialogListener");
}
listener = PhotoSourceDialogListener.class.cast(activity);
}
#Override
public void onDetach() {
super.onDetach();
listener = null;
}
#Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
return new AlertDialog.Builder(getActivity())
.setTitle(R.string.photo_source)
.setItems(R.array.photo_sources, this).create();
}
#Override
public void onClick(DialogInterface dialog, int which) {
String choice = getResources().getStringArray(
R.array.photo_sources)[which];
if (listener!=null) {
listener.onPhotoSourceSelected(choice);
}
}
}
and to invoke it i do this in my activity:
PhotoSourceDialog dialog = new PhotoSourceDialog();
dialog.show(getSupportFragmentManager(), PhotoSourceDialog.class.getName());
So my question is this: Should I be worried? Is this just something that is hanging around for a bit but will eventually be GCd? I would think that if there was a leak it would grow higher than 2.

I'm closing this question. Someone at google has responded with the following:
OK, in that case then it's not an AppCompat bug since the standard
Action Bar implementation is used on ICS+.
Looking at that MAT screenshot, the framework's ActionMenuItemView is
being referenced from a clipboard event which is being finalized,
hence about to be GC'd. The LayoutInflater is probably the
LayoutInflater that the Activity keeps itself (getLayoutInflater()).

Android Setting Up Splash Screen(Activity) Like Iphone Part1

I have three images with me and i want them to appear on first layout xml like a splash view so that they can be viewed only once i.e that activity will be called only once when app get's installed or if app get's a new update otherwise app should always start from the Second activity, i don't know how should i begin with this :
Can any one tell me any idea how this can be done.
To show splash for only once.
Next part of this question is here
Coding will be much appreciated.

Save a flag in the Preferences when you start up the application, after you've done the welcome screen stuff. Check for this flag before you show the welcome screen. If the flag is present (in other words, if it's not the first time), don't show it.
In your activity:
SharedPreferences mPrefs;
final String welcomeScreenShownPref = "welcomeScreenShown";
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
mPrefs = PreferenceManager.getDefaultSharedPreferences(this);
// second argument is the default to use if the preference can't be found
Boolean welcomeScreenShown = mPrefs.getBoolean(welcomeScreenShownPref, false);
if (!welcomeScreenShown) {
// here you can launch another activity if you like
// the code below will display a popup
String whatsNewTitle = getResources().getString(R.string.whatsNewTitle);
String whatsNewText = getResources().getString(R.string.whatsNewText);
new AlertDialog.Builder(this).setIcon(android.R.drawable.ic_dialog_alert).setTitle(whatsNewTitle).setMessage(whatsNewText).setPositiveButton(
R.string.ok, new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
}
}).show();
SharedPreferences.Editor editor = mPrefs.edit();
editor.putBoolean(welcomeScreenShownPref, true);
editor.commit(); // Very important to save the preference
}
}

Try this :
public class MainActivity extends Activity {
private Thread mSplashThread;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
try {
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.splash);
final MainActivity sPlashScreen = this;
mSplashThread = new Thread() {
#Override
public void run() {
try {
synchronized (this) {
wait(4000);
}
} catch (InterruptedException ex) {
}
finish();
Intent intent = new Intent();
intent.setClass(sPlashScreen, StartNewActivity.class);// <-- Activity you want to start after Splash
startActivity(intent);
}
};
mSplashThread.start();
} catch (Exception e) {
}
}
#Override
public boolean onTouchEvent(MotionEvent evt) {
try {
if (evt.getAction() == MotionEvent.ACTION_DOWN) {
synchronized (mSplashThread) {
mSplashThread.notifyAll();
}
}
} catch (Exception e) {
}
return true;
}
}
you put an Image in splash.xml to show

to do this you have to detect the first launch of your application. To do so you can store a boolean value as #Nirav suggested.
And for the splash screen, You can consider using Fragments and ViewPager to create an activity which will only be shown for the first time