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how to pass data using intent in xamarin

i'm new in developing android in xamarin i just want to ask in how to pass data through other activity using intent ? This thing work (https://developer.xamarin.com/recipes/android/fundamentals/activity/pass_data_between_activity/) but i want to collect first all the data in 2 activity before they show the summary in my 3rd activity.(by the way i'm creating a registration app thanks for the future answers :) )

On the first activity you create the second activity by an intent and use the method PutExtra to pass the data you want with a relevant key name that you will need after starting the new activity to retrieve the data.
var secondActivity = new Intent (this, typeof(SecondActivity));
secondActivity.PutExtra ("Data", "Sample Data");
StartActivity(secondActivity);
On second activity OnCreate retrieve the data using the key name it was stored with and the correct method relevant to the data type passed. In this example as is a string by calling Intent.GetStringExtra.
string text = Intent.GetStringExtra ("Data") ?? "Data not available";
You can repeat 1 & 2 for the summary activity.

you can pass whole object and desterilize that in another activity like this
//To pass:
intent.putExtra("yourKey", item);
// To retrieve object in second Activity
getIntent().getSerializableExtra("yourKey");
For only single value you can use
//Method 1
string code = Intent.GetStringExtra("id") ?? string.Empty;
string name = Intent.GetStringExtra("Name") ?? string.Empty;
//OR
//Method 2
string Id = Intent.GetStringExtra("id") ?? string.Empty;
Item item = new Item();
item = itemRepo.Find(Convert.ToInt32(id));

Passing multiple data to an Activity?

I'm trying to pass multiple data items in one Intent:
if (strActStat == "Sedentary") {
// passactStat.putString("keySedentary", strActStat);
// passSeden.putString("keyMale", gender);
i = new Intent(CalorieTrackerTargetWeight.this, TargetWeightResults.class);
i.putExtra("keyGender", gender);
i.putExtra("keyAct", strActStat);
//i.putExtra("keyAct", strActStat);
startActivity(i);
}
Why doesn't this work? Why can't I pass multiple items in one Intent?

You can't compare strings with ==.
if (strActStat.equals("Sedentary")) { // should work
Edit:
#Hesam has written a pretty detailed answer but his solution is not really usable. Instead of using an ArrayList<String> you should stick with the putExtra(key, value). Why? Well there are some advantages over the ArrayList solution:
you are not limited to the type of the ArrayList
you are not forced to keep a static order in you list. As you can only work with index values to get a list you need to make sure that the put() was in the same order as get(). Think of the following case: You you often send 3 values, but in some cases you don't want to send the second value. When you use the ArrayList solution, you end up sending null as the second value to ensure that the third value will stay in his place. This is highly confusing coding! Instead you should just send two values and when the receiving activity tries to receive the second value, it can handle the returning null like it want... for example replace it with a default value.
Naming of the key will grant you the knowledge of always knowing what should be inside...
Your key should be declared in the receiving Activity as a constant. So you always know by looking at this constants what intent data the activity can handle. This is good programming!
Hope this helps in clarifying the intent usage a bit.

I think this is not the only problem, first, if (strActStat == "Sedentary") this is wrong. you can't compare to string in this way. Because in this way objects are comparing not the string. Correct way is if (strActStat.equalIgnoreCase("Sedentary")).
If you use Parcelable then you can pass multiple data in just 1 intent.
Also you can use ArrayList<String>.
Here is a skeleton of the code you need:
Declare List
private List<String> test;
Init List at appropriate place
test = new ArrayList<String>();
and add data as appropriate to test.
Pass to intent as follows:
Intent intent = getIntent();
intent.putStringArrayListExtra("test", (ArrayList<String>) test);
Retrieve data as follows:
ArrayList<String> test = data.getStringArrayListExtra("test");
Hope that helps.

Try this:
done.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
namevalue=name.getText().toString();
overvalue=over.getText().toString();
audiostatus=audio.getText().toString();
Intent intent=new Intent(Settings.this,home.class);
Bundle bundle = new Bundle();
bundle.putString( "namevalue",namevalue);
bundle.putString("overvalue",overvaluse);
bundle.putInt("value",variablename);
intent.putExtras(bundle);
startActivity(intent);
}
});

I faced the same problem.
My mistake was that one of the variable I was transferring was not initialized.
Like gender or strActStat in your case.

How to pass object to an activity?

I have two activities, NewTransferMyOwn.java and FromAccount.java
When I go from NewTransferMyOwn.java to FromAccount.java, I do write code as following
Intent i = new Intent(NewTransferMyOwn.this, FromAccount.class);
startActivityForResult(i, FROM_ACCOUNT);
When I do come back from FromAccount.java to NewTransferMyOwn.java, then I want to pass a complete object of class Statement
I do write code as
Statement st = ItemArray.get(arg2);//ItemArray is ArrayList<Statement>, arg2 is int
Intent intent = new Intent(FromAccount.this,NewTransferMyOwn.class).putExtra("myCustomerObj",st);
I do get error as following on putExtra,
Change to 'getIntExtra'
as I do, there is again casting st to int, what is issue over here, how can I pass Statement object towards back to acitivity?

You can also implement your custom class by Serializable and pass the custom Object,
public class MyCustomClass implements Serializable
{
// getter and setters
}
And then pass the Custom Object with the Intent.
intent.putExtra("myobj",customObj);
To retrieve your Object
Custom custom = (Custom) data.getSerializableExtra("myobj");
UPDATE:
To pass your custom Object to the previous Activity while you are using startActivityForResult
Intent data = new Intent();
Custom value = new Custom();
value.setName("StackOverflow");
data.putExtra("myobj", value);
setResult(Activity.RESULT_OK, data);
finish();
To retrieve the custom Object on the Previous Activity
if(requestCode == MyRequestCode){
if(resultCode == Activity.RESULT_OK){
Custom custom = (Custom) data.getSerializableExtra("myobj");
Log.d("My data", custom.getName()) ;
finish();
}
}

You can't pass arbitrary objects between activities. The only data you can pass as extras/in a bundle are either fundamental types or Parcelable objects.
And Parcelables are basically objects that can be serialized/deserialized to/from a string.
You can also consider passing only the URI refering to the content and re-fetching it in the other activity.

myIntent.getStringExtra returns null? [duplicate]

This question already has an answer here:
Android Intent.getStringExtra() returns null
(1 answer)
Closed 1 year ago.
I'm having a weird problem when I try to send strings with intents when switching activities.
Here is what I do in class 1:
Intent myIntent = new Intent(SearchText.this, Search.class);
myIntent.putExtra("searchx", spinnerselected);
myIntent.putExtra("SearchText", input);
startActivity(myIntent);
Class 2:
Intent myIntent = getIntent();
searchText=myIntent.getStringExtra("SearchText");
spinnerselectednumber=Integer.parseInt(myIntent.getStringExtra("searchx"));
And using the debugger in the second class, its clear that there is a value in
searchx.
Though the line myIntent.getStringExtra("searchx") returns null .
Why is this?

Try to add .ToString() to myIntent.putExtra("searchx", spinnerselected); so that it is myIntent.putExtra("searchx", spinnerselected.ToString()); This always works for me

Was spinnerSelected a String?
From the Javadoc for Intent
public String getStringExtra(String name)
Since: API Level 1
Description: Retrieve extended data from the intent.
Parameters:
name The name of the desired item.
Returns: The value of an item that previously added with putExtra() or null if no String value was found.
There seems to be many ways to retrieve "extras" - whatever the type of spinnerSelected was, try to retrieve it using the appropriate method.
Eg if it was an int:
public int getIntExtra(String name, int defaultValue)

This code should work:
Bundle extras = getIntent().getExtras();
return extras != null ? extras.getString("searchx")
: "nothing passed in";

Transfer data from one Activity to Another Activity Using Intents

I would like to be able to transfer data from one activity to another activity. How can this be done?

Through the below code we can send the values between activities
use the below code in parent activity
Intent myintent=new Intent(Info.this, GraphDiag.class).putExtra("<StringName>", value);
startActivity(myintent);
use the below code in child activity
String s= getIntent().getStringExtra(<StringName>);

There are couple of ways by which you can access variables or object in other classes or Activity.
A. Database
B. shared preferences.
C. Object serialization.
D. A class which can hold common data can be named as Common Utilities it depends on you.
E. Passing data through Intents and Parcelable Interface.
It depend upon your project needs.
A. Database
SQLite is an Open Source Database which is embedded into Android. SQLite supports standard relational database features like SQL syntax, transactions and prepared statements.
Tutorials -- http://www.vogella.com/articles/AndroidSQLite/article.html
B. Shared Preferences
Suppose you want to store username. So there will be now two thing a Key Username, Value Value.
How to store
// Create object of SharedPreferences.
SharedPreferences sharedPref = PreferenceManager.getDefaultSharedPreferences(this);
//now get Editor
SharedPreferences.Editor editor = sharedPref.edit();
//put your value
editor.putString("userName", "stackoverlow");
//commits your edits
editor.commit();
Using putString(),putBoolean(),putInt(),putFloat(),putLong() you can save your desired dtatype.
How to fetch
SharedPreferences sharedPref = PreferenceManager.getDefaultSharedPreferences(this);
String userName = sharedPref.getString("userName", "Not Available");
http://developer.android.com/reference/android/content/SharedPreferences.html
C. Object Serialization
Object serlization is used if we want to save an object state to send it over network or you can use it for your purpose also.
Use java beans and store in it as one of his fields and use getters and setter for that
JavaBeans are Java classes that have properties. Think of
properties as private instance variables. Since they're private, the only way
they can be accessed from outside of their class is through methods in the class. The
methods that change a property's value are called setter methods, and the methods
that retrieve a property's value are called getter methods.
public class VariableStorage implements Serializable {
private String inString ;
public String getInString() {
return inString;
}
public void setInString(String inString) {
this.inString = inString;
}
}
Set the variable in you mail method by using
VariableStorage variableStorage = new VariableStorage();
variableStorage.setInString(inString);
Then use object Serialzation to serialize this object and in your other class deserialize this object.
In serialization an object can be represented as a sequence of bytes that includes the object's data as well as information about the object's type and the types of data stored in the object.
After a serialized object has been written into a file, it can be read from the file and deserialized that is, the type information and bytes that represent the object and its data can be used to recreate the object in memory.
If you want tutorial for this refer this link
http://javawithswaranga.blogspot.in/2011/08/serialization-in-java.html
Get variable in other classes
D. CommonUtilities
You can make a class by your self which can contain common data which you frequently need in your project.
Sample
public class CommonUtilities {
public static String className = "CommonUtilities";
}
E. Passing Data through Intents
Please refer this tutorial for this option of passing data.
http://shri.blog.kraya.co.uk/2010/04/26/android-parcel-data-to-pass-between-activities-using-parcelable-classes/

When you passing data from one activity to another activity perform like this
In Parent activity:
startActivity(new Intent(presentActivity.this, NextActivity.class).putExtra("KEY_StringName",ValueData));
or like shown below in Parent activity
Intent intent = new Intent(presentActivity.this,NextActivity.class);
intent.putExtra("KEY_StringName", name);
intent.putExtra("KEY_StringName1", name1);
startActivity(intent);
In child Activity perform as shown below
TextView tv = ((TextView)findViewById(R.id.textViewID))
tv.setText(getIntent().getStringExtra("KEY_StringName"));
or do like shown below in child Activity
TextView tv = ((TextView)findViewById(R.id.textViewID));
TextView tv1 = ((TextView)findViewById(R.id.textViewID1))
/* Get values from Intent */
Intent intent = getIntent();
String name = intent.getStringExtra("KEY_StringName");
String name1 = intent.getStringExtra("KEY_StringName1");
tv.setText(name);
tv.setText(name1);

Passing data from one activity to other in android
Intent intent = new Intent(context, YourActivityClass.class);
intent.putExtra(KEY, <your value here>);
startActivity(intent);
Retrieving bundle data from android activity
Intent intent = getIntent();
if (intent!=null) {
String stringData= intent.getStringExtra(KEY);
int numberData = intent.getIntExtra(KEY, defaultValue);
boolean booleanData = intent.getBooleanExtra(KEY, defaultValue);
char charData = intent.getCharExtra(KEY, defaultValue); }

Hopefully you will find the answer from here Send Data to Another Activity - Simple Android Login

You just have to send extras while calling your intent
like this:
Intent intent = new Intent(getApplicationContext(), SecondActivity.class); intent.putExtra("Variable Name","Value you want to pass"); startActivity(intent);
Now on the OnCreate method of your SecondActivity you can fetch the extras like this
If the value u sent was in "long"
long value = getIntent().getLongExtra("Variable Name which you sent as an extra", defaultValue(you can give it anything));
If the value u sent was a "String"
String value = getIntent().getStringExtra("Variable Name which you sent as an extra");
If the value u sent was a "Boolean"
Boolean value = getIntent().getStringExtra("Variable Name which you sent as an extra",defaultValue);

Your Purpose
Suppose You want to Go From Activity A to Activity B.
So We Use an Intent to switch activity
the typical code Looks Like this -
In Activity A [A.class]
//// Create a New Intent object
Intent i = new Intent(getApplicationContext(), B.class);
/// add what you want to pass from activity A to Activity B
i.putExtra("key", "value");
/// start the intent
startActivity(i);
In Activity B [B.class]
And to Get the Data From the Child Activity
Intent i = getIntent();
if (i!=null) {
String stringData= i.getStringExtra("key");
}

This works best:
Through the below code we can send the values between activities
use the below code in parent activity(PARENT CLASS/ VALUE SENDING CLASS)
Intent myintent=new Intent(<PARENTCLASSNAMEHERE>.this,<TARGETCLASSNAMEHERE>.class).putExtra("<StringName>", value);
startActivity(myintent);
use the below code in child activity(TARGET CLASS/ACTIVITY)
String s= getIntent().getStringExtra(<StringName>);
Please see here that "StringName" is the name that the destination/child activity catches while "value" is the variable name, same as in parent/target/sending class.