This is what i want to do. When a user starts the game, he is taken to a dashboard screen with several categories that he is suppossed to choose from. On clicking any of the categories one is lead to to the a single activity where i need to know how to find which category button was choosen in the ActivityB.
So, in the DashboardActivity, i have this code:
public void onGeneralKnowledgeClick(View v) {
createIntent("GENERAL_KNOWLEDGE", 1);
}
........
........
........
public void onCelebritiesClick(View v) {
createIntent("CELEBRITIES", 6);
}
private void createIntent(String category, int result) {
Bundle bundle = new Bundle();
bundle.putInt(category, result);
Intent intent = new Intent(this.getApplicationContext(),
QuestionActivity.class);
intent.putExtras(bundle);
startActivityForResult(intent, 0);
}
Now, in my QuestionActivity class, i have a method that tries to get the categoryNumber associated with the intent that was started. So, i have something like this:
private int getCategory() {
Bundle bundle = this.getIntent().getExtras();
int categ = bundle.getInt("GENERAL_KNOWLEDGE");
return categ;
}
My problem is that, how do i return the integer category such and not hardcording as i did up here. I want this method to return a the integer from the respective bundle. my idea is to have a switch statement inside the getCategory but i don't know what case value to use. Also, i saw someone saying that onActivityResult can be used but i don't see how.
Please help!
I believe you're a bit confused. You merely need to do:
bundle.putInt("CATEGORY", result); //where result == the categoryId and "CATEGORY" is always "CATEGORY"
Then in your getCategory():
int categ = bundle.getInt("CATEGORY") //you'll get the int value that you fed before
Unless I misunderstood.
Related
I have an app that for right now, consists of 2 buttons (will later consists of 20+). When I click on a button, it takes me to a new activity that has a list of items I can select. After selecting something and clicking the Back button, it starts a new activity that passes on the item's information (in this case, "orange") and then it assigns the word "orange" to the button that was clicked.
Now when I click on the other button to assign it's information, I lose all of my first button information. What are my options for saving the previous information? Would I have to create an intent for it and keep passing it back and forth between actvities?
At the end, I need to collect all the information that was assigned to both buttons and pass that onto another activity, as this is just the customizing page. Is there a way I can just have the Strings set such that leaving the activity won't delete the String information?
Here's my MainActivity
Bundle extras = getIntent().getExtras();
if (extras != null) {
btnValue = extras.getString("btnValue");
itemValue = extras.getString("itemValue");
}
if (btnValue.equals("btn1")){
btn1.setText(itemValue);
} else if (btnValue.equals("btn2")) {
btn2.setText(itemValue);
}
}
public void onClickBtn1(View v) {
Intent myIntent = new Intent(this, Main2Activity.class);
myIntent.putExtra("btn", "btn1");
startActivity(myIntent);
}
public void onClickBtn2(View v) {
Intent myIntent = new Intent(this, Main2Activity.class);
myIntent.putExtra("btn", "btn2");
startActivity(myIntent);
}
and my 2nd activity
Bundle extras = getIntent().getExtras();
if (extras != null) {
btnValue = extras.getString("btn");
}
listView = (ListView) findViewById(R.id.list);
String[] values = new String[] { "apple", "banana", "orange", "cherry"};
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, android.R.id.text1, values);
listView.setAdapter(adapter);
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view,int position, long id) {
itemPosition = position;
itemPositionString = String.valueOf(itemPosition);
}
});
}
public void onClickBack (View v) {
Intent intent = new Intent(this, MainActivity.class);
intent.putExtra("btnValue", btnValue);
intent.putExtra("itemValue", itemValue);
startActivity(intent);
}
You can use the Android lifecycle to manage the activity's state.
To save the activity state you need to do your work on the method onSaveInstanceState.
onSaveInstanceState(Bundle bundle)
On restoration you either check the bundle the following methods
onRestoreInstanceState(Bundle bundle)
onCreate(Bundle bundle)
You can find more details here:
https://developer.android.com/training/basics/activity-lifecycle/recreating.html
When you use startActivity it creates new activity. So you lose old information. You need to use startActivityForResult from MainActivity while starting second activity and from the second activity you should use setResult
Intent returnIntent = new Intent();
returnIntent.putExtra("result",result);
setResult(RESULT_OK, returnIntent);
finish();
And you handle the result in MainActivity with
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
..
..
}
Here, there is an example How to manage `startActivityForResult` on Android?
You basically have 3 choices:
Pass all data in the Intent and return any new/changed data in another Intent using startActivityForResult().
Save the data in a static variable somewhere (globals). All activities can then reference the current data and make changes to it that are then seen by all other activities. This is the quick-and-dirty solution which is suitable for small, trivial or "homework" solutions.
Save the data in a persistent storage (a file or an SQLite database). All activities can read all the current data, display it and make changes. After the BACK button is pressed, the underlying Activity should read the current data from the persistent storage to refresh the views.
I explained this badly originally. This is my question: The Intent I send to the startActivity() method, contains a private field, mMap, which is a Map containing the strings I sent to putExtra(). When the target activity starts, a call to getIntent() returns an Intent that does not contain those values. The mMap field is null. Obviously, something in the bowels of the View hierarchy or the part of the OS that started the new activity created a new Intent to pass to it, since the object IDs are different.
But why? And why are the putData() values not carried fowrard to the new Intent?
The activity that starts the new activity extends Activity. Here's the startup code:
public boolean onOptionsItemSelected(final MenuItem item) {
switch (item.getItemId()) {
case 4:
i = new Intent(this, StatList.class);
i.putExtra("Name1", "Test1");
i.putExtra("Name3", "Test2");
startActivity(i);
}
}
I've tried the key values with and without the (recommended) complete package name prefix.
In the Eclipse debugger, I have verified the values for the player names are being inserted into i.mExtras.mMap properly.
Here's the code from the startee:
public class StatList extends ListActivity {
private final StatsListAdapter statsAdapter;
public StatList() {
statsAdapter = StatsListAdapter.getInstance(this);
} // default ctor
#Override
public void onCreate(final Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
final Intent i = getIntent();
final Bundle extras = i.getExtras();
< more code here >
}
When execution gets to this method, mIntent.mExtras.mMap is null, and mIntent.mExtras.mParcelledData now contains some values that don't look sensible (it was null when startActivity() was called). getIntent() returns mIntent.
I've also tried startActivityForResult(), with the same result.
From the docs and the samples I've seen online & in the sample apps, this should be easy. I've found another way to meet my immediate need, but I'd like to know if anyone can help me understand why something this simple doesn't work.
In your main Activity:
i = new Intent(this, StatList.class);
i.putExtra("Name1", "Test1");
i.putExtra("Name3", "Test2");
startActivity(i);
Then in StatList.class
Bundle extras = getIntent().getExtras();
String name1 = extras.getString("Name1");
String name3 = extras.getString("Name3");
Log.i("StatList", "Name1 = " + name1 + " && Name3 = " + name3)
Update the following two line
final Intent i = getIntent();
final Bundle extras = i.getExtras();
Replace it with
Bundle extras = getIntent().getExtras();
if(extras!= null){
String var1= extras.getString("Name1");
String var2= extras.getString("Name2");
}
Question is simple, I am not exactly new to Android but I cannot, for the life of me, retrieve the extras passed via an intent from Activity A to Activity B.
See Activity A: This is actually a ListFragment, that implements onListItemClick() to start another activity via an intent.
#Override
public void onListItemClick(ListView l, View v, int position, long id) {
Log.i("FragmentList", "Item clicked: " + id);
Intent i = new Intent(getActivity(), ExpandedTweetView.class);
twitter4j.Status status = adapter.getItem(position);
Bundle extras = new Bundle();
extras.putString(KEY_TEXT, status.getText());
extras.putString(KEY_HANDLE, status.getUser().getScreenName());
extras.putString(KEY_NAME, status.getUser().getName());
extras.putString(KEY_TIMESTAMPS, status.getCreatedAt().toString());
extras.putLong(KEY_RETWEETS, status.getRetweetCount());
i.putExtra(KEY_EXTRAS, extras);
startActivity(i);
}
This part just works, I tested it usng Log.v(TAG, "status.getText()" to make sure that the error was not coming from the Adapter passing an empty item via getItem().
Here is the code on Activity B:
public class ExpandedTweetView extends Activity {
TextView text;
TextView name;
TextView handle;
TextView createdAt;
TextView retweets;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.expanded_list_item);
Bundle extras = getIntent().getExtras();
ActionBar actionBar = getActionBar();
actionBar.setHomeButtonEnabled(true);
actionBar.setDisplayHomeAsUpEnabled(true);
text = (TextView) findViewById(R.id.h_content);
name = (TextView) findViewById(R.id.h_name);
handle = (TextView) findViewById(R.id.h_handle);
createdAt = (TextView) findViewById(R.id.h_timestamp);
retweets = (TextView) findViewById(R.id.h_retweet_count);
if(extras != null) {
text.setText(extras.getString(TimelineFragment.KEY_TEXT));
name.setText(extras.getString(TimelineFragment.KEY_NAME));
handle.setText(extras.getString(TimelineFragment.KEY_HANDLE));
createdAt.setText(extras.getString(TimelineFragment.KEY_TIMESTAMPS));
retweets.setText(String.valueOf(extras.getLong(TimelineFragment.KEY_RETWEETS)));
}
}
As you can see, I believe I am using the right code to obtain the extras, using the same code on other applications worked. Not sure why, when the ExpandedTweetView is created via an intent, ALL of the textViews are empty. See: https://www.dropbox.com/s/pso6jbyn6rpks9n/empty_activity.png
What is even MORE strange is that I had initially tried checking to see if the bundle was null by calling this:
if (extras == null) {
Log.v(TAG, "Extras are empty :(");
}
But that line was never executed, meaning the bundle is not null. I also thought that maybe the keys being used to retrieve the individual Strings from the bundle were mismatching; however, in order to remedy that I decided to create constants that could be used on both sides. As you can see on the code, both the key to set the Extra and the Key to retrieve the Extra are the same.
Any ideas as to what the heck is going on?
Bundle extras = getIntent().getExtras();
if (extras != null) {
extras = extras.getBundle("KEY_EXTRAS");
String status = extras.getString("KEY_TEXT");
}
Try adding the extra variable to intent rather than in Bundle
Ex:
i.putExtra(KEY_1, a);
i.putExtra(KEY_2, b);
i.putExtra(KEY_3, c);
Then retrieve it from other activity from intent
Ex:
getIntent().getStringExtra(KEY_1) ;
In Activity A:
Intent i = new Intent(MainActivity.this, AnotherActivity.class);
Bundle b = new Bundle();
b.putString("thisc", "my name");
i.putExtra("bundle", b);
startActivity(i);
In Activity B:
**Bundle bun = getIntent().getBundleExtra("bundle");
if (bun.containsKey("thisc")) {
Log.i("TAG", bun.getString("thisc"));
} else {
Log.i("TAG", "no thisc");
}**
Check the first line of code in Activity B, that's the main difference actually!!
//put value
Intent inatent = new Intent(this,text.class);
inatent_logo.putExtra("message","hello");
startActivity(inatent);
//get vale
String msg = getIntent().getStringExtra("message").toString();
It's Difficult to maintain intent to Bundle and Bundle to Intent if number of data you want ti share from one Activity to Other Activity.
just Simply use Intent with PuExtra() with different argument.
you can pass number of data in intent like :
Sender's Side :
Create your Intent.
Intent My_Intent = new Intent(FromClass.this,ToClass.class);
Add your value which you want to share with other activity.
My_Intent.putExtra("VAR_A",a_value);
My_Intent.putExtra("VAR_B",b_value);
My_Intent.putExtra("VAR_C",c_value);
Call your Intent.
StartActivity(My_Intent);
Receiver's Side :
Intent My_Intent = getIntent();
First_Value=My_Intent.getStringExtra("VAR_A");
Sec_Value=My_Intent.getStringExtra("VAR_B");
Thred_Value=My_Intent.getStringExtra("VAR_C");
I Think its Easy for you to Handel your data from one Activity to other .
I am new to android so please excuse the newbie question. I have a game I am trying to port from an old Java applet to android. My goal is to get this functional and then post an article on a site like CodeProject (or a better one if there are ones more appropriate). The idea is to show that a person brand new to android development can create an app in a reasonable amount of time.
I am making some progress but have run into a problem. I have the main activity in which the user interacts with. I then created a menu item that in turn starts a second activity (call it child) with a modest number of checkbox's, seekbar's etc to fill in parameters. I can successfully pass the class containing all the options from main to child. But I cannot get the child to pass this data back to the main.
First here is my main code that starts the child activity:
public void addBalls()
{
Intent myIntent = new Intent(this, GameOptions.class);
Bundle b = new Bundle();
b.putSerializable("options", gameParams);
myIntent.putExtras(b);
startActivityForResult(myIntent,STATIC_OPTIONS_VALUE);
}
The data passed to the child (and hopefully back again) is:
public class GameOptionParams implements Serializable
{
private static final long serialVersionUID = 1L;
public int speedBarPosition;
public int vgravityBarPosition;
public int mgravityBarPosition;
public int viscosityBarPosition;
public int restititionBarPosition;
public boolean trace;
public boolean collide;
public boolean mush;
public boolean wrap;
public boolean flicker;
}
And here is the expected return (again in main)
#Override
public void onActivityResult(int requestCode, int resultCode, Intent data)
{
super.onActivityResult(requestCode, resultCode, data);
switch(requestCode)
{
case (STATIC_OPTIONS_VALUE) :
{
if (resultCode == Activity.RESULT_OK)
{
//retrieve intended options
Bundle b = data.getExtras();
gameParams = (GameOptionParams) b.getSerializable("options");
}
break;
}
}
}
The child activity successfully receives the gameParams data. It then interacts with the user to update the values and then I attempt to return it but it does not seem to get sent to main. Here is the child code in the onStop() override.
Maybe this code should not be in the onStop() override but I can't determine where else to place it.
#Override
public void onStop()
{
super.onStop();
//read widget values
gameParams.speedBarPosition = speedBar.GetPosition();
gameParams.vgravityBarPosition = vgravityBar.GetPosition();
gameParams.mgravityBarPosition = mgravityBar.GetPosition();
gameParams.viscosityBarPosition = viscosityBar.GetPosition();
gameParams.restititionBarPosition = restititionBar.GetPosition();
//todo save to persistent
Intent resultIntent = new Intent(this, TiltBall2ImpactActivity.class);
Bundle b = new Bundle();
b.putSerializable("options", gameParams);
resultIntent.putExtras(b);
setResult(Activity.RESULT_OK, resultIntent);
}
Back in the main onActivityResult override I always see requestCode=0, resultCode=0, data=null. I assume this is a typical newbie problem, I have been reading the sdk documentation, user forums etc and have come close to a solution but just not quite there yet. Any help would be appreciated.
Since this is sort of a setting menu for the game, I assume you are going to need these values for more than one activity. If so you extend the android.app.Application class.
In that class you can create attributes to hold your values. In any activity you can call
MyApplication myApp = (MyApplication)getApplicationContext();
where myApp is a singleton. So you will get the values you set from another activity.
You will need to add this code to your application tag in the manifest file for it to work
android:name=".MyApplication"
If you need to keep these values for next startup of the application, you need to use SharedPreferences. This is a good tutorial for that
http://saigeethamn.blogspot.com/2009/10/shared-preferences-android-developer.html
Assuming in your 'child' activity, the user has to press an 'OK' or 'Save' button then put the code to set the gameParams parameters in the button's onClick(...) handler.
Use the default constructor for instantiating the Intent, example...
Intent resultIntent = new Intent();
...then after creating the Bundle and adding gameParams to it and calling setResult(...), simply call finish() to terminate the 'child' activity. There aren't many occasions that I can think of to override onStop() and I suspect you don't want to be using it to attempt returning the Intent.
I've two String Arrays like that ,
String[] htmlArray = {
"file:///android_asset/Pinocchio/OPS/chapter-001.xml",
"file:///android_asset/Pinocchio/OPS/chapter-002.xml",
"file:///android_asset/Pinocchio/OPS/chapter-035.xml",
"file:///android_asset/Pinocchio/OPS/chapter-035.xml"
};
String[] htmlArray1 = {
"file:///android_asset/Harry_Potter/OEBPS/part1.xhtml",
"file:///android_asset/Harry_Potter/OEBPS/part2_split_000.xhtml",
"file:///android_asset/Harry_Potter/OEBPS/part18_split_000.xhtml",
"file:///android_asset/Harry_Potter/OEBPS/part18_split_001.xhtml",
};
then, I put two ImageView in another class,
private void init() {
pino_cover = (ImageView) findViewById(R.id.pino_cover);
pino_cover.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent reader=new Intent(instance,ReaderScreen.class);
reader.putExtra("pino",true);
startActivity(reader);
}
});
harry_cover=(ImageView) findViewById(R.id.harry_cover);
harry_cover.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent reader=new Intent(instance,ReaderScreen.class);
reader.putExtra("harry",true);
startActivity(reader);
}
});
}
Then, if I click the Pino Image, I could get the data through htmlArray .
Intent i=getIntent();
Bundle b = i.getExtras();
String newText = b.
String setext=b.getString("harry");
if (newText=="pino")
pages = htmlArray;
else
pages = htmlArray1;
but if I click the Harry Image, it'd been taken to get the data through the htmlArray too. I want to get htmlArray1.
How could I get ?
You are putting only a boolean to your intent, but you could use .putExtra(mStringArray, htmlArray1); as this method exists to pass arrays through intents...?
Plus, to compare two strings in java, you MUST NOT do == but .equals(""). In your case if(newText.equals("harry))...
EDIT
Ok, in an easier version, you have that :
Intent i=getIntent();
Bundle b = i.getExtras();
String newText = b.
String setext=b.getString("harry");
if (newText=="pino")
pages = htmlArray;
else
pages = htmlArray1;
replace it by that :
Intent i=getIntent();
Bundle b = i.getExtras();
String newText = b.
String setext=b.getString("harry");
if (newText.equals("pino"))
pages = htmlArray;
else
pages = htmlArray1;
This should logically work.
I think the error lies in your using "==" to compare 2 string as mentioned above.
Please use str1.equals(str2) instead of str1 == str2.
And the answer by Sephy suggests you pass the 2 html arrays to the called activity as well. If for some reasons, the called activity can still access the 2 arrays then you can just do as you have done.
Also, in the map you passed, if you use 2 different keys (one is "harry", and one is "pino"), it seems to defeat the purpose. I suggest sth like:
on harry event:
i.putExtra("data", harry_html_array)
on pino event:
i.putExtra("data", pino_html_array)
Inside the called activity:
array = extras.getStringArray("data");