Well I have a main Screen with 5 buttons. Each time a press a button I want to go a new screen. So far I have other 5 classes (each for each screen) and 5 xmls. But Iam sure that there will be a better way beacuse this screen and the xmls are the same, and what I want to do is change some texts and some data I fetch from a database. I am sure that I can ony another class and only one xml and then pass the values that I want as arguments. (Imagine that in its final state my app must have 15 buttons, so I think it is too mych waste of space and unnecessary to have 15 .java files and 15 xml files that look the same and only some values of images and textviews change). My code for main activity is:
public class MyActivity extends Activity {
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
main2Theme();}
private void main2Theme() {
setContentView(R.layout.main_new);
Button Button100 = (Button)findViewById(R.id.Button100);
Button113.setOnClickListener(new OnClickListener()
{
public void onClick(View v)
{
Intent i = new Intent(this, OtherScreenName.class);
startActivity(i);
}
}); //and so on for 15 buttons
My OtherScreenName.class is:
public class OtherScreenName extends Activity {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Theme();
}
#SuppressWarnings("null")
private void Theme() {
Log.d("SnowReportApp","Do first thing");
setContentView(R.layout.otherscreenname); //THIS CHANGES IN EVERY CLASS DEPENDING ON THE ID OF THE BUTTON
String result = "";
InputStream is = null;
StringBuilder sb=null;
ArrayList<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();//() before
nameValuePairs.add(new BasicNameValuePair("ski_id","OtherScreenName"));
TextView text1 = (TextView) findViewById(R.id.otherscreenname_1);
//THESE 2 CHANGE DEPERNDING ON THE BUTTON PRESSED
//perform action.....
//AND ALSO HERE I NEED THE ID OF THE BUTTON
b1.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
Intent i = new Intent(OtherScreenName.this,MyActivity.class);
startActivity(i);
}
});
Can anyone suggest how to give arguments to my class and what it should be the type of them?
If I understand your question correctly, you want to pass arguments to the activity. Normally it would be done through the class constructor, however, activities can't have user defined constructors, only the default one; they can be instantiated only indirectly via intent creation. If you need to pass data between activities, do it by putting extras to bundles, for example:
bundle.putInt("intName",intValue);
then you can extract the data from bundle by
int intValue = bundle.getInt("intName");
Put extras before starting the activity:
Intent i = new Intent(this, YourActivity.class);
Bundle b = new Bundle();
b.putInt("intName",intValue);
i.putExtras(b);
startActivity(i);
and then read the extras in the onCreate method:
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
Bundle b = getIntent().getExtras();
int intValue;
if (b != null)
{
intValue= b.getInt("intName");
}
}
The same way you can pass other data types as String boolean etc. If this is not sufficient and you need to pass some more complex data, then use Parcelable interface.
You can pass parameters with an Intent by adding extra's to it, something like the following:
Intent i = new Intent(this, MyActivity.class);
i.putExtra("paramName", "value");
startActivity(i);
In your activity you can use the getIntent() method to retrieve the Intent and extract your parameter(s) from it:
Intent i = getIntent();
Bundle extras = i.getExtras();
String param = extras.getString("paramName", "default value");
You can place all the different text and data in your Intent, but you can also decide based on the value of an Intent parameter which data and text to retrieve. If it is a lot of data or text you are probably better off using the second approach.
If you want to pass object instead of simple data, you must use parcelable objects as it´s explained in: [http://developer.android.com/reference/android/os/Parcelable.html][1]
Reading and writing with parcelable objects is very similar to the way with a simple data
Intent intent = new Intent(this ,newthing.class);
Bundle b = new Bundle();
b.putParcelable("results", listOfResults);
intent.putExtras(b);
startActivityForResult(intent,0);
Intent i = getIntent();
Bundle extras = i.getExtras();
String param = extras.getParcelable("results");
Related
This question already has answers here:
How do I pass data between Activities in Android application?
(53 answers)
How to pass an object from one activity to another on Android
(35 answers)
Closed 4 years ago.
I am currently working on a project for my programming class, it is a d&d character creator I've decided to do for my final project. I am nearly finished with it but have run into one problem. I want to take the user's data from a screen where they create a character and store it into a screen where they can view their created characters, but I am not sure how to do this. This is the code from the create a character screen:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_new_char_screen);
Button btnSave = (Button)findViewById(R.id.btnSaveChar);
btnSave.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (checkData())
startActivity(new Intent(NewCharScreen.this, HomeScreen.class));
}
});
Button btnEx = (Button)findViewById(R.id.btnExplanation);
btnEx.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
startActivity(new Intent(NewCharScreen.this, ExplanationScreen.class));
}
});
}
private boolean checkData(){
final EditText charName = (EditText) findViewById(R.id.txtNameInput);
if (charName.getText().toString().isEmpty()){
charName.setError("Enter character name");
charName.requestFocus();
return false;
}
return true;
}
}
If there is a need for the rest of my code or the project itself here is a link to a repository on GitHub:
https://github.com/cbetlinski98/MAD105-final_project
If you want to pass data from one activity to another one, you should pass it inside the Intent object, so intead of creating it inside StartActivity you can create it outside as a normal object, and use putExtra() to put data inside it.
Intent intent = new Intent(getBaseContext(), DestinationActivity.class);
intent.putExtra("OBJECT_PARAM_NAME", your_object);
startActivity(intent);
To recover data on the other activity you can use
String sessionId= getIntent().getStringExtra("OBJECT_PARAM_NAME");
Pass basic types
If you need to pass basic objects like int, float, strings, you can always pass them with putExtra() but to take them in the destination activity there are relative methods like getStringExtra() or getIntExtra() and many others.
Pass your class
If your user is a class defined by you, you can implement Serializable in that class, put it inside the intent with putExtra() and recover it from the other activity with getIntent().getSerializableExtra("OBJECT_PARAM_NAME") and then just cast it to your class before putting it inside an object
In order to pass information across intents:
Intent i = new Intent(this, Character.class);
myIntent.putExtra("paramKey","paramValue1");
startActivity(i);
Then in your activity to obtain the parameters:
Intent i2 = getIntent();
i2.getStringExtra("paramKey");
startActivity(new Intent(CurrentActivity.this, AnotherActivity.class).putExtra(KEY, DATA));
So I have this fab menu and each button have different activity what I want is to put the functions into one java file instead of creating a lot of java file to call different functions in the button
Here's the one of the java file - SVAuditorium.class.
public class SVAuditorium extends AppCompatActivity {
private static final LatLng Auditorium = new LatLng(10.294335, 123.880809);
#Override
protected void onCreate(final Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.street_view);
SupportStreetViewPanoramaFragment streetViewPanoramaFragment =
(SupportStreetViewPanoramaFragment)
getSupportFragmentManager().findFragmentById(R.id.streetviewpanorama);
streetViewPanoramaFragment.getStreetViewPanoramaAsync(
new OnStreetViewPanoramaReadyCallback() {
#Override
public void onStreetViewPanoramaReady(StreetViewPanorama panorama) {
if (savedInstanceState == null) {
panorama.setPosition(Auditorium);
}
}
});
}
}
This is what I did to call the activities from the SVAuditorium and the rest.
case R.id.fab_auditorium:
startActivity(new Intent(this, SVSAuditorium.class));
break;
case R.id.fab_library:
startActivity(new Intent(this, SVLibrary.class));
break;
case R.id.fab_main:
startActivity(new Intent(this, SVMainBuilding.class));
break;
As you have stated that you only have changes in lat-long in each of your Activity, I would suggest keeping a single activity like you want and pass the lat-long through intent. Here's a sample code showing how you can achieve the behaviour.
Intent intent = new Intent(MainActivity.this, SVActivity.class);
Bundle longLat = new Bundle();
longLat.putDouble("LONGITUDE", longitude);
longLat.putDouble("LATITUDE", latitude);
intent.putExtras(longLat);
startActivity(intent);
Get the latitude and longitude in your SVActivity like this.
Bundle longLat = getIntent().getExtras();
double longitude = longLat.getDouble("LONGITUDE");
double latitude = longLat.getDouble("LATITUDE");
Initialize your views based on the value found in your SVActivity.
the Latlng is only different
Since LatLng implements Parcelable
You need only need one Java file and you can pass the LatLng through an Intent using Intent.putExtra("latlng", latlng), where you define that variable per clicked item
See answer - Android: How to pass Parcelable object to intent and use getParcelable method of bundle?
Then in that one Activity's onCreate method, you can LatLng latlng = getIntent().getParcelableExtra("latlng")
I've got two different activities Menu and Exercise.
I need to pass some data from Menu to Exercise when I start the latter activity via the click of a button.
Here is the code in Menu activity:
Button b = (Button) findViewById(R.id.temp);
b.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v){
Intent i = new Intent(context, ExerciseActivity.class);
Bundle b = new Bundle();
b.putString("colors","Blue");
b.putIntArray("workoutlist",new int[] {0,1});
i.putExtras(b);
//i.putExtra("workoutlist",MyApp.workoutList.get(0));
//i.putExtra("colors","Blue");
startActivity(i);
}
});
Using debugging tools I've checked that all the data are inside the bundle of the intent properly.
And here is the code that should retrieve data from the intent in Exercise Activity:
Intent in = getIntent();
Bundle b = in.getExtras();
String[] colorSets = (String[]) b.get("colors");
int[] l = (int[]) b.get("workoutlist");
The fact is when I get the bundle it is empty, and obviously I cannot proceed.
Moreover I already used almost the same code between to other activities and everything is working fine.
Why is this happening? Is it there something I'm missing which generates this error? Maybe some incompatibility between the two activities?
Thank you for your help!
you add String using putString() and get it using getString(). the same goes for other types.
Intent in = getIntent();
Bundle b = in.getExtras();
String colorSets = b.getString("colors");
int[] l = b.getIntArray("workoutlist");
I need to randomly generate a button and then grab elements from it from the activity that the button opens. Specifically the universal ID of a "character" that I have specified in PersistentData. (That whole class works fine, though. The problem is between this activity and the next.) The child activity has multiple activities that can call it. (There are several activities with lists made from different characters from a pool, and each list has these buttons that are shown below, which all point to the same activity that loads information from PersistentData based on the data that its supposed to pull from said button.) The following 1 block of code is in the onCreate method for this activity. (Automatically generated, I just added this in after I called the layouts from the XML file)
for (fID = 0; fID < PersistentData.fName.size(); fID++) {
if (PersistentData.fName.get(fID) != null) {
Button[] Btn = new Button[PersistentData.fName.size()];
Btn[fID].setHeight(200);
Btn[fID].setWidth(200);
Btn[fID].setTextSize(40);
Btn[fID].setText(PersistentData.fName.get(fID));
Btn[fID].setTag(fID);
Layout.addView(Btn[fID]);
Btn[fID].setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
int btnID = fID;
gotoActivity(v);
}
});
} else continue;
}
Here is gotoActivity(). (In the class, not onCreate)
public void gotoActivity(View view) {
Intent intent = new Intent(this, TargetActivity.class);
startActivity(intent);
intent.putExtra("btnClicked", /*IDK WHAT TO PUT RIGHT HERE*/);
}
I have put several things there, actually. Mostly, they have been various ways of declaring a variable on the creation of the button.
Here's the TargetActivity.class
public class Fighter extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_fighter);
Intent intent = getIntent();
Bundle bundle =
intent.getExtras(); //line ***
**
TextView viewName = (TextView) findViewById(R.id.fighterName);
viewName.setText(PersistentData.fName.get(fID));
}
}
What should I put in the other class that I should get here**? (fID) is the thing that I'm trying to get. I have tried putting and getting fID using the methods as described in the Create an Activity page from Android and it continued to give me a NullPointerException at line *** (I split the line to be precise.)
Any help is appreciated. I would not be surprised if there is a better way to do this, requiring me to scrap all my work and restart. I would prefer not to, though lol. I will be checking this post periodically throughout the day, so if you have any questions or require more detail, just post or message me. Thank you beforehand.
I think the reason you got a NullPointerException because you started the activity before persing the extra.
In the gotoActiviy, make sure the extra(s) method are called before you start the activity. that is
public void gotoActivity(View view) {
Intent intent = new Intent(this, TargetActivity.class);
intent.putExtra("btnClicked", "Strings");
startActivity(intent);
}
As you can see, a string was the extra, you can put any variable type as the extra just make sure at the activity being called, the same variable type gets the extra.
as an example
String getValue = getIntent().getExtras().getString("btnClicked");
Int getValue = getIntent().getExtras().getInt("btnClicked");
/** If integer was the value activity extra */
This question already has answers here:
How do I pass data between Activities in Android application?
(53 answers)
Closed 9 years ago.
I'm wondering how to pass and read a string that is in one activity from another activity. I have two activities. I'll call them Activity1 and Activity2. I have a string in Activity1 called course. I want to read that string in Activity2.
I've tried doing this but the string came out empty.
public class Activity2 extends Activity1 {
I've seen people use the Intent function but I couldn't figure out how to use it.
Any suggestions? Thanks!
Pass values using intents.
In your first activity
Intent i= new Intent("com.example.secondActivity");
i.putExtra("key",mystring);
// for explicit intents
// Intent i= new Intent(ActivityName.this,SecondActivity.class);
// parameter 1 is the key
// parameter 2 is the value
// your value
startActivity(i);
In your second activity retrieve it.
Bundle extras = getIntent().getExtras();
if (extras != null) {
String value = extras.getString("key");
//get the value based on the key
}
To pass custom objects you can have a look at this link
http://www.technotalkative.com/android-send-object-from-one-activity-to-another-activity/
your first activity, Activity1
public class Activity1 extends Activity {
Button btn;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity1);
btn=(Button) findViewById(R.id.payBtn);
btn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View arg0) {
Intent intent=new Intent(Activity1.this,Activity2.class);
intent.putExtra("course", "courseValue");
startActivity(intent);
}
});
}
}
Activity2
public class Activity2 extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity2);
String course=getIntent().getExtras().getString("course").toString();
Log.d("course",course);
}
}
Hope this will help you.
You're on the right track - you're using an intent to launch the second activity. All you have to do is add intent.putExtra("title", stringObject); where stringObject is the string you want to pass, and title is the name you want to give that object. You use that name to refer the object passed in the second activity as follows:
String s = (String)getIntent().getExtras().getSerializable("title");
From Activity 1 call something like this :
Intent intent= new Intent("path.secondActivity");
intent.putExtra("keyString",sampleString);
startActiivty(intent);
and in activity 2 try something like this :
Bundle values = getIntent().getExtras();
if (values != null) {
String keyString = values.getString("keyString");
}
In your MainActivity
Intent i= new Intent(MainActivity.this,SecondActivity.class);
i.putExtra("key",yourstring);
startActiivty(i);
In your second activity onCreate()
Bundle extras = getIntent().getExtras();
if (extras != null) {
String value = extras.getString("key");
}
Try this
public class Activity2 extends Activity1