Hi everyone.
I'm new in android and I'm working on an app in which I need to recall the same activity to enter the information of a variable amount of entities (passengers).
I have the following:
btnContinue3.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
for (int i=0; i<Pssngr; i++){
passenger[i] = new
Intent(getApplicationContext(), Pasajeros.class);
startActivity(passenger[i]);
}
}
});
Pssngr is the amount of passsengers or entites that need a unique activity to get their information entered.
The trigger is the button then the activities will be called one by one following an array
I try this code but after clicking on the button the app crashed.
Please someone help me find a way to make this work.
thanks
It crashes because You are trying to start x number of Activities at once.
If You have to run new Activity for each of Passengers best in this scenario will be startActivityForResult
I beliver effect You trying to get is that user clicks on button just once and activities for each passenger will open one after another.
To do it in method onClick You will start only first activity, don't use loop.
You start consequently next activities in onActivitiyResult
In addition to what Gustek mentions above, a better way to approach this would be to have one activity and just pass the different values from the parent (PassengersAvitivty) activity through the intent as below:
final Intent intent = new Intent(PassengersAcitivty.this, PassengersEntityActivity.class);
intent.putExtra("PASSENGER_FIRSTNAME", passenger[i].getName());
intent.putExtra("PASSENGER_LASTNAME", passenger[i].getLastName());
intent.putExtra("PASSENGER_EMAIL", passenger[i].getEmail());
startActivity(intent);
and here is how you can retrieve them on your activity (PassengerEntityActivity)
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Bundle extras = getIntent().getExtras();
if (extras != null)
{
firstname = extras.getString("PASSENGER_FIRSTNAME");
lastname = extras.getString("PASSENGER_LASTNAME");
email = extras.getString("PASSENGER_EMAIL");
}
else
{
//Log.v("NO VALUE", "OOPS");
}
I can clarify further if needed.
Related
I have an activity which can be accessed via different activities.
Like you have one activity containing a listview and the second containing a gridview and both shows the same data. When you click on an item a new activity with some details is shown. I need to somehow remember which activity was the initial one (with gridview or listview) so that I can set a button to redirect here. But it's not enough to just return to previous activity (like using finish() to close the current one), because there is a way to navigate among different objects from inside the details activity (I have a gridview on that screen). So I need to remember the initial view during moving through the details activity for various number of times.
Is there a way?
EDIT: omg why so many downvotes? At least tell me why it is so stupid, I'm learning coding for Android for 2 weeks how am I supposed to know everything??
This sounds like it would best be solved by using two Fragments within the same Activity
You can use a bundle object to pass data to the new activity (B) so you could know wich activity (listView or gridView) had started it.
In activity B:
private static final String ACTIVITY_TYPE = "activity_type";
public static Intent createIntent(Context context,String activityType)
{
Intent intent = new Intent(context, ActivityB.class);
Bundle b = new Bundle();
b.putString(ACTIVITY_TYPE,activityType);
intent.putExtras(b);
return intent;
}
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
Bundle b = getIntent().getExtras();
String activityType;
if (b != null)
{
activityType = b.getString(ACTIVITY_TYPE);
}
//the calling activity didn't use the createIntent method and didn't provide the activity type
else
{
activityType = "some_default_type";
}
//save activity type to use later
//rest of your code
}
In the calling activity:
Intent intent = ActivityB.createIntent(ActivityListView.this,"activity_list_view");
startActivity(intent);
this is my first question being asked on stackoverflow. My question is regarding variable use across different recyclable intents.
e is declared like this.
final Bundle e=getIntent().getExtras();
Here i am creating new intents for different setOnClickListener() and passing a different variable for each intent.
Intent info = new Intent(EItemListView.this, ItemInfo.class);
Bundle extras = new Bundle();
int[] a=new int[listview.getAdapter().getCount()];
if (i == 0) {
extras.putIntArray("img", n5x_images);
extras.putString("info", n5x_info);
extras.putInt("pc",a[0]);
} else if (i == 1) {
extras.putIntArray("img", op3_images);
extras.putString("info", op3_info);
extras.putInt("pc",a[1]);
}
info.putExtras(extras);
startActivity(info);
Now this is the OnClickListener() where i am trying to update the variables which i passed through the intent extras, but am unable to update those variables.
addtc.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
int c=e.getInt("pc");
c=c+1;
Log.i("Log","value "+c);
}
The log message which i get from the above method is always 1, i think the variable in c is always set to 0 and then increments by 1 and hence the log message shows 1.
I need the variables a[0],a[1],a[2], etc to pertain its increment operation.
To make it more clear, this is the java file i am using. The error is in the OnClickListener of addtc button at the bottom of this code.
public class ItemInfo extends AppCompatActivity {
private ViewAnimator viewanimator;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_item_info);
Button next=(Button)findViewById(R.id.bnext);
Button prev=(Button)findViewById(R.id.bprev);
viewanimator=(ViewAnimator)findViewById(R.id.viewAnimator);
TextView info=(TextView)findViewById(R.id.item_info);
Button addtc=(Button)findViewById(R.id.badd);
Button test=(Button)findViewById(R.id.button);
Bundle e=getIntent().getExtras();
int img[]=e.getIntArray("img");
for(int i=0;i<img.length;i++)
{
ImageView imgview = new ImageView(getApplicationContext());
imgview.setImageResource(img[i]);
viewanimator.addView(imgview);
}
info.setText(e.getString("info"));
next.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
viewanimator.showNext();
}
});
prev.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
viewanimator.showPrevious();
}
});
addtc.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
int c=e.getInt("pc");
c=c++;
Log.i("Log","value "+c);
}
});
}
}
Thanks in advance!!!
Your approach is wrong. You cannot do this in this way. Your understanding of what an "extra" in an Intent is incorrect.
When you do this:
extras.putInt("pc",a[1]);
This adds an "extra" to the extras Bundle. The Bundle is simply a key/value pair map and you have added an entry that contains the key "pc" and the value is whatever a[1] is. It puts a copy of the value of a[1] into the Bundle, it does not put a reference to a[1] in the Bundle.
Therefore, if a[1] is 5 when you add it to the extras Bundle, a[1] will always be 5 and will never be changed to anything else.
You can't do this in this way.
Alternative: Depending on your application architecture and what you are trying to do, you can use one of the following methods:
1) Use startActivityForResult(), pass the data from one Activity to another, have the second Activity update the data and put it back into the Intent which is then returned to the "calling" Activity by using setResult().
2) Use a static variable (basically a "global" variable) to contain the data. Both activities can then access the data directly (you don't need to put the data in the Intent.
3) Put the data in a database. Both activities can then read/write from/to the database.
First advice I can give you is debugging and posting debug result. for example, are you sure that a[0] and a[1] aren't 0?
Assuming they are not, why are you declaring the bundle as final? referring to this probably final is not what you were looking for. Try removing it or replacing with private
Another suggestion is more for readable purpose, replace c = c+1; with c++; but this doesn't change the result, it just make it more linear and easier for reading.
Now after this fix (the final keyword one) tell me if something changed please :)
Please how do I link a new activity from my main activity using a clickable text. I have set the text to clickable from my main.xml but I don't know how to call the new activity from my MainActivity.java class. I know I have to use this code "textView.setOnClickListener(new View.OnClickListener());" I found in a similar question, but I don't know how and where to place it on my MainActivity.java class so that it calls a the next activity I named display
Check out Intent. You use these to start new activities or services within your application.
You're correct in that you have to assign an OnClickListener interface to your text, after you made it clickable. In the interface's onClick() method you would need to do something like this.
For example:
#Override
public void onClick(View v) {
// Create the intent which will start your new activity.
Intent newActivityIntent = new Intent(MainActivity.this, NewActivity.class);
// Pass any info you need in the next activity in your
// intent object.
newActivityIntent.putExtra("aString", "some_string_value");
newActivityIntent.putExtra("anInteger", some_integer_value);
// Start the new activity.
startActivity(newActivityIntent);
}
In the next activity, you can retrieve the intent used to start it, so that you'll have access to the data you passed from the first activity, like so:
#Override
public void onCreate(Bundle savedInstanceState) {
// Get the intent that started this activity.
Intent startingIntent = getIntent();
// Retrieve the values.
String aString = startingIntent.getStringExtra("aString");
Integer anInteger = startingIntent.getIntExtra("anInteger", 0); // 2nd param is the default value, should "anInteger" not exist in the bundle.
// Use the values to your hearts content.
}
Hope that helps.
new to droid programming. im having a small problem that im sure is simply fixed but ive done some searching and a bunch of tutorials but cant seem to find just what i need so i figured id ask. My app has 2 activites, the first activity is just a simple form where a user enters course information(class title, professor..etc.)
the first activity passes the data which is supposed to be stored in a list in the second activity. problem is that only the first course gets stored in the list, after the first time nothing new gets added to the second activity. Can someone point me in the right direction please? thanks in advance
First Activity
public class CourseDetail extends Activity {
//Course c = new Course();
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Button save=(Button)findViewById(R.id.save);
save.setOnClickListener(onSave);
}
private View.OnClickListener onSave=new View.OnClickListener() {
public void onClick(View v) {
EditText course=(EditText)findViewById(R.id.course);
EditText professor=(EditText)findViewById(R.id.professor);
EditText location=(EditText)findViewById(R.id.location);
EditText officehrs=(EditText)findViewById(R.id.officehrs);
Intent i=new Intent(CourseDetail.this, CourseList.class);
i.putExtra("myCourse", course.getText().toString());
i.putExtra("myProfessor", professor.getText().toString());
i.putExtra("myLocation", location.getText().toString());
i.putExtra("myOfficehrs", officehrs.getText().toString());
startActivity(i);
}
};
}
Second Activity
public class CourseList extends Activity {
Button btnCourse;
List<Course> model = new ArrayList<Course>();
CourseAdapter adapter=null;
private String dCourse="";
private String dProfessor="";
private String dLocation="";
private String dOfficehrs="";
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.clist);
ListView list =(ListView)findViewById(R.id.courses);
adapter=new CourseAdapter();
list.setAdapter(adapter);
Course c = new Course();
Bundle extras = getIntent().getExtras();
dCourse = extras !=null ? extras.getString("myCourse") :"no value entered";
dProfessor = extras !=null ? extras.getString("myProfessor") :"no value entered";
dLocation = extras !=null ? extras.getString("myLocation") :"no value entered";
dOfficehrs = extras !=null ? extras.getString("myOfficehrs") :"no value entered";
c.setCourse(dCourse);
c.setProfessor(dProfessor);
c.setLocation(dLocation);
c.setOfficeHrs(dOfficehrs);
btnCourse =(Button)findViewById(R.id.btnCourse);
btnCourse.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
finish();
}
});
}
You are just getting the user entered value in CourseDetail activity and displaying the received value inside the CourseList activity, that means you are not storing these values permanently.
Go through this Android - Data Storage document.
When you move to 2nd activity i.e. CourseList activity, at that time fetch the data from the SQLite table and display the same. whenever you get new values from previous activity, at that time just update the list by adding the new data in ArrayList and make a call on adapter.notifyDataSetChanged()
Some suggestions:
Have your CourseList extend ListActivity instead of just Activity - check out some tutorials on that which should help you set things up correctly.
There seems to be a bit of confusion with how you're handling your lists - you have your model variable but don't seem to be doing anything with it. Again, have a look at a ListView tutorial (just google "android listview tutorial").
You seem to have figured out that you can use "intents" to pass information from one activity to another, but since you're only doing this in the onCreate() method, it's only happening once. Try doing this in your ListActivity's adapter once for each item.
Don't give up on Android, keep trying :-)
Some suggestion:
You have to add your object to the adapter: adapter.add(c); after you get the data.
Call adapter.notifyDataSetChanged() to notify the system that your data for the listView has been changed. Call list.invalidate() to refresh it.
I noticed that you set the button with the finish() method. Hmm, if you do so, the next time you get to CourseList Activity from CourseDetail, the adapter will be null again. No previously received data will be available. Is this what you really want?
The problem is you are not adding the newly added items to the List.So before setting adapter you have to add all your objects like
list.add(c);
I'm making Sudoku game. There are two classes: difficulty and Screen class. When the 'easy' button is pressed, I want to generate a random number from 1 to 9, and that numbers should go to the Screen class layout.
My 'easy' button is in choosedifficulty class layout.
You can pass information between activities using Intent extras. In your case, you could do (assuming I understood what you wanna do):
public void startSudoku(int chosenDifficulty) {
Intent i = new Intent(this, // Your current activity
SudokuActivity.class); // The activity showing the Sudoku
i.addExtra("com.example.sudoku.DifficultyLevel", chosenDifficulty);
startActivity(i);
}
Then, in the onCreate method of your Sudoku activity, you can get the difficulty level:
private int difficulty = 0;
protected void onCreate(Bundle savedInstanceState) {
Bundle extras = getIntent().getExtras();
if (extras != null) {
difficulty = extras.getInt("com.example.sudoku.DifficultyLevel", 0);
}
}
Be carefull cause a sudoku is not only "random numbers from 1 to 9", so I recommend you to implement the algorithm properly. (Take a look at http://en.wikipedia.org/wiki/Sudoku_algorithms).
About passing data from one activity to another, you can use the intent. For example:
//In the place you launch your game
Intent myIntent = new Intent(myContext, Screen.class);
//sudoku is a String, for example, that contains the sudoku you want to pass
myIntent.putExtra("sudokukey", sudoku);
startActivity(myIntent);
And then, to retrieve the data:
Bundle bundle = getIntent().getExtras();
String mySudoku = bundle.getString("sudokukey");