I'm currently writting an app for Android. I'm trying to figure out the best place to catch on intent when the activity is created for the first time.
public class DisplayAct extends Activity {
private Intent mNewIntent;
private ViewFinderFragment mViewFinderFrag;
public boolean toot;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState)
getWindow().setFlags(WindowManager.LayoutParams.FLAG_HARDWARE_ACCELERATED, WindowManager.LayoutParams.FLAG_HARDWARE_ACCELERATED);
setContentView(R.layout.activity_display);
if(savedInstanceState != null) {
Intent intent = getIntent();
if (intent != null) {
String action = intent.getAction();
}
}
This is how I get the intent.
I was wondering if grabbing the intent at oncreate is good or it's better to add onStart and add this action inside in term of design perspective.
Thanks
If you app is open, handle it with onNewIntent. If you app is closed, you wanna use your Bundle that comes with your Intent.
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (savedInstanceState.getString(MY_ACTION)) {
// Do something
}
EDIT:
I set this action as a String to the Intent's Bundle. I performed it with the code below:
Bundle bundle = new Bundle();
bundle.putString(MainActivity.MY_ACTION, "MY_ACTION");
Intent intent = new Intent(this, MainActivity.class);
intent.putExtras(bundle);
Related
I have Act_01 (where I put value) and Act_02 (where I get value) but have declared these methods in a Extras class, getting value from Act_02 returns null value:
Act_01: (Where I want to pass the value Name to Act_02)
public class Act_01 extends Activity {
Extras cc_Extras;
Button btn1;
Intent intent;
String str_Name;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.act_01);
cc_Extras = new Extras();
str_Name = "Buck";
btn1 = (Button) findViewById(R.id.btn1);
btn1.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
cc_Extras.putExtras();
startActivity(intent);
}
});
}
}
Act_02: (Where I want ot receive value Name from Act_01 but the app crashes with null value)
public class Act_02 extends Activity {
Extras cc_Extras;
String str_Name;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.act_02);
cc_Extras = new Extras();
if(getIntent() != null && getIntent().getExtras() != null)
{
cc_Extras.getExtras();
}
Toast.makeText(getApplicationContext(), "Name: "+str_Name, Toast.LENGTH_SHORT).show();
}
}
Extras: (Where I define the methods to put and get Extras)
public class Extras extends Activity {
String str_Name;
Intent intent;
public void putExtras() {
// TODO Auto-generated method stub
intent.putExtra("KEY_Name", str_Name);
}
public void getExtras() {
// TODO Auto-generated method stub
str_Name = getIntent().getExtras().getString("KEY_Name");
}
}
EDIT: I do not want to pass and get data directly between activities, I want to use the 3rd class (Extras.java) because I have too many activities having too many values between each other and want to sort of define them globally in Extras so that all my other activities can just call one method instead of getting and putting too many values in my activities.
Your app crashes not with a null value, but a null pointer reference because you created a new Activity manually
cc_Extras = new Extras();
Then called a lifecycle method on it
cc_Extras.getExtras()
Which calls getIntent(), but the Intent was never setup by the Android framework, and cc_Extras.getExtras() wouldn't have any of the data you wanted anyway in the second Activity because it was just created there, not from the first Activity.
Briefly, you should never make a new Activity, and your Extras class does not need to be an Activity in the first place (nor does it provide much benefit).
Just use the Intent object provided by the first Activity to start the second Activity, and get extras like normal. Don't overcomplicate your code. Regarding the title of the question, Intent and Bundle are already "another class" designed by Android for you to transfer data.
On both activities you are creating a new instances of Extras class means they dont hold the same value you can do this to transfer data from A to B
public class Act_01 extends Activity {
Button btn1;
Intent intent;
String str_Name;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.act_01);
str_Name = "Buck";
btn1 = (Button) findViewById(R.id.btn1);
btn1.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
intent = new Intent(Act_01.this, Act_02.class);
intent.putExtra("data", str_Name)
startActivity(intent);
}
});
}
}
And receieve data like this
public class Act_02 extends Activity {
String str_Name;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.act_02);
// cc_Extras = new Extras();
if(getIntent() != null)
{
if (getIntent().getStringExtra("data") != null) {
Toast.makeText(Act_02.this, "Name: "+getIntent.getStringExtra("data"), Toast.LENGTH_SHORT).show();
}
}
}
}
Also you should consider using Activity Context instead of the application context
Ok! so here are the few things I might wanna suggest you to correct.
Changes needs to be done in the code.
You are not assigning anything to "intent" object , and you have passed a intent without assigning anything to it.
Your instance cc_Extra isn't doing anything in the activity1. You might wanna pass the "intent" object in your constructor of class like cc_Extras= new Extras(intent); and in the Extras class do the following- Intent intent;
Extras(Intent i)
{
this.intent=i;
}
In the activity2 you are creating the new Instance of Extras(). So according to your code it is going to be NULL by default. If you have done the changes from the previous step, you can create new instance by doing cc_Extras(getIntent());
Corrections in the code
1) In Extras class getExtras() method instead of str=getIntent() use str=intent.getExtras.getString().
2) In the activity2 you are not assigning anything to your String str_Name, so you need to return the string you got in getExtras() method. You can do it by changing the return type to String. Below is the sample code.
public String getExtras()
{
str_Name=intent.getExtras().getString("KEY_Name");
//OR
//str_Name=intent.getStringExtra("KEY_Name");
return str_Name;
}
3) By the doing this you need to catch this string in the activity2 by doing `
if(getIntent() != null && getIntent().getExtras() != null)
{
str_Name=cc_Extras.getExtras();
}`
4) Another thing is you must create intent like this-
Intent intent=new Intent(currentActivityName.this,anotherActivity2.class);
//then use the intent object
EDIT- Your code must look like this in the end...
Act1
public class Act_01 extends Activity {
Extras cc_Extras=null;
Button btn1;
String str_Name;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.act_01);
str_Name = "Buck";
btn1 = (Button) findViewById(R.id.btn1);
btn1.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
//changes to do
Intent intent= new Intent(Act01.this,Act02.class);
cc_Extras= new Extras(intent);
cc_Extras.putExtras(str_Name);
//end
startActivity(intent);
}
});
}
}
Act02
public class Act_02 extends Activity {
Extras cc_Extras;
String str_Name;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.act_02);
cc_Extras = new Extras(getIntent());
if(getIntent() != null && getIntent().getExtras() != null)
{
str_Name=cc_Extras.getExtras();
}
Toast.makeText(getApplicationContext(), "Name: "+str_Name, Toast.LENGTH_SHORT).show();
}
}
Extras class
public class Extras { //remove "extends Activity" because it is a class not a activity
String str_Name;
Intent intent;
Extras(Intent i)
{
this.intent=i;
}
public void putExtras(String str) {
// TODO Auto-generated method stub
str_Name=str;
intent.putExtra("KEY_Name", str_Name);
}
public String getExtras() {
// TODO Auto-generated method stub
str_Name = intent.getExtras().getString("KEY_Name");
return str_Name;
}
}
Above code will work just on String. You can extend the functionality if you want.
I hope this must work to get your code working!
I develop android app. It needs save Internet data and login/password pair. I need to check that in every activity. How to do that optimally? My solution:
I create the BaseActivity class:
public class BaseActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
checkRequirements();
}
private void checkRequirements() {
if (needToCheckInternetConnection())
checkInternetConnection();
//check other requirements
}
private void checkInternetConnection() {
if (!Updater.getInstance(context).checkInternetConnection()) {
Bundle data = new Bundle();
data.putSerializable(SplashScreenActivity.FIELD_ACTION, SplashScreenActivity.Action.SHOW_TEXT);
data.putString(SplashScreenActivity.FIELD_TEXT, getString(R.string.splashScreenInternetNotAvailable));
changeActivity(SplashScreenActivity.class, data);
}
}
protected void changeActivity(Class<?> goTo, Bundle data) {
Intent intent = new Intent(context, goTo);
if (data != null)
intent.putExtras(data);
startActivity(intent);
finish();
}
}
And I extends all activity classes from this.
But finish() not working. So, how to change that architecture or force to work the finish() method?
I'm trying to send a madeObject from Start_Activity to Next_Activity after finishing Start_Activity.
How to make a code in Start_Activity and Next_Activity?
My sequence is :
1) Start_Activity.onCreate()
2) Start_Activity.makeObjectData()
3) Start_Activity.putextras(madeObject)
3) Start_Activity.startActivity() : start Next_Activity.
4) Start_Activity.finish() : finish Start_Activity
5) Next_Activity.getExtras()
Here is Start_Activity
public class Start_Activity extends Activity {
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.a_launching_activity);
:
//// makeDataObject ///
:
Intent intent = new Intent(getApplicationContext(), Next_Activity.class);
Bundle bundle = new Bundle();
bundle.putSerializable(madeDataObject);
intent.putExtras(bundle);
startActivity(intent);
finish();
}
}
This is Next_Activity
public class Next_Activity extends Activity {
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.a_launching_activity);
??? <-- How to get the madeDataObject of Start_Activity?
}
}
bundle.putSerializable takes two parameters. The first is a String. It has to be unique for this bundle object. You will use it afterwards, to retrieve your object.
bundle.putSerializable("my_unique_key", madeDataObject);
intent.putExtras(bundle);
startActivity(intent);
on Next_Activity, you can retrieve the intent with getIntent()
Intent intent = getIntent();
if (intent.getExtras() != null) {
intent.getExtras().getSerializable("my_unique_key");
}
Of course the object you are trying to pass from one activity to another has to implements Serializable
send extras to next activity as:
Intent intent = new Intent(getApplicationContext(), Next_Activity.class);
Bundle bundle = new Bundle();
bundle.putSerializable("myclass", madeDataObject);
intent.putExtras(bundle);
startActivity(intent);
finish();
Get it in next activity like:
Intent intent = getIntent();
if (intent.getExtras() != null) {
intent.getExtras().getSerializable("myclass");
}
i have to activities AnswerQuestion.java and SendAnswerToServer.java, and i want to send data from first activity to another one
on the AnswerQuestion activity i write this:
Bundle basket = new Bundle();
basket.putString("time", timeToAnswer+"");
Intent goToSendServer = new Intent(AnswerQuestion.this, SendAnswerToServer.class);
goToSendServer.putExtras(basket);
startActivity(goToSendServer);
my question what have i to write on the SendAnswerToServer activity , thank you
in SendAnswerToServer Activity:
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Bundle bundle = this.getIntent().getExtras();
if(bundle !=null)
{
//ObtainBundleData in the object
String strdata = bundle.getString("time");
//Do something here if data received
}
else
{
//Do something here if data not received
}
Activity myActivity = AssumeSomeActivityExists();
Intent openActivity = new Intent();
openActivity.setAction(Intent.ACTION_VIEW);
openActivity.setClass(myActivity,B.class);
myActivity.startActivity(openActivity);
When we do something like above how to make B instance know that it is been called and created by Activity myActivity?
Use extras with your Intent.
Smth like openActivity.putExtra("calledFromA", true)
Then in B:
protected void onCreate(Bundle savedInstanceState) { {
super.onCreate(savedInstanceState);
boolean isCalledFromA = getIntent().getBooleanExtra("calledFromA", false);
}