Pass Arraylist<? Implements Parcelable> to Activity

Pass ArrayList? implements Parcelable to Activity

• The problem is in writing out to the parcel and reading in from the parcel ...

  @Override
  public void writeToParcel(Parcel dest, int flags) {
      dest.writeString(name);
      dest.writeInt(numOfSeason);
      dest.writeInt(numOfEpisode);
  }
  
  private void readFromParcel(Parcel in) {
      name = in.readString();
      numOfSeason = in.readInt();
      numOfEpisode = in.readInt();
  }
  

• What you write out has to match what you read in...

  @Override
   protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);
  
  Intent i = new Intent(this,SecondActivity.class);
  
  ArrayList<testparcel> testing = new ArrayList<testparcel>();
  
  i.putParcelableArrayListExtra("extraextra", testing);
  startActivity(i);
  }
  
      /**********************************************/
  
  public class SecondActivity extends Activity {
  @Override
  protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);
  
      ArrayList<testparcel> testing = this.getIntent().getParcelableArrayListExtra("extraextra");
   }
  }
  

• The above code is having onCreate() from two different activities. The first one launches the second one; and it works fine I was able to pull the parcelable without issue.

Help with passing ArrayList and parcelable Activity

I can see a number of problems here:

1. Why use addressParcelable? Why not make address implement Parcelable, and then use:

   intent.putParcelableArrayListExtra( "addresses", addyExtras );
   

2. Your parcelable object must include a static CREATOR. See the documentation for details.

3. You are not actually adding any extras to the intent before you call startActivity(). See point 1 for a suggestion here.

I think that you will need to address all of these issues in order to get it working.

How to pass ArrayList of Objects from one to another activity using Intent in android?

It works well,

public class Question implements Serializable {
    private int[] operands;
    private int[] choices;
    private int userAnswerIndex;

   public Question(int[] operands, int[] choices) {
       this.operands = operands;
       this.choices = choices;
       this.userAnswerIndex = -1;
   }

   public int[] getChoices() {
       return choices;
   }

   public void setChoices(int[] choices) {
       this.choices = choices;
   }

   public int[] getOperands() {
       return operands;
   }

   public void setOperands(int[] operands) {
       this.operands = operands;
   }

   public int getUserAnswerIndex() {
       return userAnswerIndex;
   }

   public void setUserAnswerIndex(int userAnswerIndex) {
       this.userAnswerIndex = userAnswerIndex;
   }

   public int getAnswer() {
       int answer = 0;
       for (int operand : operands) {
           answer += operand;
       }
       return answer;
   }

   public boolean isCorrect() {
       return getAnswer() == choices[this.userAnswerIndex];
   }

   public boolean hasAnswered() {
       return userAnswerIndex != -1;
   }

   @Override
   public String toString() {
       StringBuilder builder = new StringBuilder();

       // Question
       builder.append("Question: ");
       for(int operand : operands) {
           builder.append(String.format("%d ", operand));
       }
       builder.append(System.getProperty("line.separator"));

       // Choices
       int answer = getAnswer();
       for (int choice : choices) {
           if (choice == answer) {
               builder.append(String.format("%d (A) ", choice));
           } else {
               builder.append(String.format("%d ", choice));
           }
       }
       return builder.toString();
     }
  }

In your Source Activity, use this :

  List<Question> mQuestionList = new ArrayList<Question>;
  mQuestionsList = QuestionBank.getQuestions();
  mQuestionList.add(new Question(ops1, choices1));

  Intent intent = new Intent(SourceActivity.this, TargetActivity.class);
  intent.putExtra("QuestionListExtra", ArrayList<Question>mQuestionList);

In your Target Activity, use this :

  List<Question> questions = new ArrayList<Question>();
  questions = (ArrayList<Question>)getIntent().getSerializableExtra("QuestionListExtra");

Kotlin Passing ListArray to another Activity using Parcelable

Use something like this...

   class Series() : Parcelable {
  private var name: String? = null
  private var numOfSeason: Int = 0
  private var numOfEpisode: Int = 0

  constructor(parcel: Parcel) : this() {
    val data = arrayOfNulls<String>(3)
    parcel.readStringArray(data)
    this.name = data[0]
    this.numOfSeason = Integer.parseInt(data[1])
    this.numOfEpisode = Integer.parseInt(data[2])
  }

  override fun writeToParcel(parcel: Parcel, flags: Int) {
    parcel.writeString(name);
    parcel.writeInt(numOfSeason);
    parcel.writeInt(numOfEpisode);
  }

  private fun readFromParcel(parcel: Parcel){
    name = parcel.readString()
    numOfSeason = parcel.readInt()
    numOfEpisode = parcel.readInt()
  }
  override fun describeContents(): Int {
    return 0
  }

  companion object CREATOR : Creator<Series> {
    override fun createFromParcel(parcel: Parcel): Series {
      return Series(parcel)
    }

    override fun newArray(size: Int): Array<Series?> {
      return arrayOfNulls(size)
    }
  }

}

and then in your Activity

override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.main_activity)

        val i = Intent(this, SecondActivity::class.java)

val testing = ArrayList<testparcel>()

i.putParcelableArrayListExtra("extraextra", testing)
startActivity(i)
}

class SecondActivity :Activity() {
    override fun onCreate(savedInstanceState: Bundle?) {
       super.onCreate(savedInstanceState)
        setContentView(R.layout.secondActivty_activity)

val testing = this.intent.getParcelableArrayListExtra<Parcelable>("extraextra")
    }
}

intent.putExtra a list of Parcelable objects and enums

You don't need to make List parcelable. To put it, just use existing method.

final Intent i = new Intent(this,SecondActivity.class);
final ArrayList<Product> list = new ArrayList< Product >();
i.putParcelableArrayListExtra(PRODUCT_KEY, list);
startActivity(i);

To retrieve almost in the same way.

final ArrayList<Product> list = this.getIntent()
            .getParcelableArrayListExtra(PRODUCT_KEY);

UPDATE

To answer you newer question. You cannot pass generic List inside. Because by List you could have different collection. To know system, which type to use you need to have explicit type.

// This will work. 
final ArrayList<Department> departments = getSpecificDepartments();
intent.putParcelableArrayListExtra(DEPARTMENTS_KEY, departments);

Android Class Parcelable with ArrayList

If you need to pass an ArrayList between activities, then I'd go with implementing Parcelable also, as there is no other way around I guess.
However I don't think you will need that much of getters and setters. Here is your Question class which implements Parcelable:

public class Question implements Parcelable {
    public String id;
    public String text;
    public String image;
    public ArrayList<Choice> choices;

    /**
     * Constructs a Question from values
     */
    public Question (String id, String text, String image, ArrayList<Choice> choices) {
        this.id = id;
        this.text = text;
        this.image = image;
        this.choices = choices;
    }

    /**
     * Constructs a Question from a Parcel
     * @param parcel Source Parcel
     */
    public Question (Parcel parcel) {
        this.id = parcel.readString();
        this.text = parcel.readString();
        this.image = parcel.readString();
        this.choices = parcel.readArrayList(null);
    }

    @Override
    public int describeContents() {
        return 0;
    }

    // Required method to write to Parcel
    @Override
    public void writeToParcel(Parcel dest, int flags) {
        dest.writeString(id);
        dest.writeString(text);
        dest.writeString(image);
        dest.writeList(choices);
    }

    // Method to recreate a Question from a Parcel
    public static Creator<Question> CREATOR = new Creator<Question>() {

        @Override
        public Question createFromParcel(Parcel source) {
            return new Question(source);
        }

        @Override
        public Question[] newArray(int size) {
            return new Question[size];
        }

    };
}

How do I pass arraylist of a custom object from one java class to another?

Serializable and Parcelable are not the same thing, although they serve the same purpose. This post contains an example of the Parcelable object.

The pattern employed should be followed for all Parcelable objects you want to create, changing only the writeToParcel and AddValues(Parcel in) methods. These two methods should mirror eachother, if writeToParcel writes an int then a string, the constructor should read an int then a string

Parcelable

public class AddValues implements Parcelable{
    private int id;
    private String value;

    // Constructor
    public AddValues (int id, String value){
        this.id = id;
        this.value= value;
   }

   // Parcelling part
   public AddValues (Parcel in){
       this.id = in.readInt();
       this.value= in.readString();
   }

   @Override
    public int describeContents() {
        return 0;
    }

   @Override
   public void writeToParcel(Parcel dest, int flags) {
       dest.writeInt(id);
       dest.writeString(value);
   }

   public final Parcelable.Creator CREATOR = new Parcelable.Creator() {
       public AddValues createFromParcel(Parcel in) {
           return new AddValues(in); 
       }

       public AddValues[] newArray(int size) {
           return new AddValues[size];
       }
   };

}

Adding the list to an Intent extra should be simple now

Put List extra

ArrayList<AddValue> list = new ArrayList<>();
Intent intent = new Intent(BluetoothLeService.this,HomePageFragment.class);
intent.putExtra("arg_key", list);

Get List extra

ArrayList<AddValues> list = (ArrayList<AddValues>) intent.getSerializableExtra("arg_key");

As an aside, you can use the Pair<Integer, String> object instead of creating an AddValues object. This doesn't affect the answer, but might be nice to know.

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