如何在Android中使用Intent将对象的ArrayList从一个传递到另一个activity？

Question

我的onclick()方法中有以下代码作为

 List<Question> mQuestionsList = QuestionBank.getQuestions();

现在我在这一行后面有了意图，如下所示：

  Intent resultIntent = new Intent(this, ResultActivity.class);
  resultIntent.putParcelableArrayListExtra("QuestionsExtra", (ArrayList<? extends Parcelable>) mQuestionsList);
  startActivity(resultIntent);

我不知道如何把这个问题列表从一个activity的意图传递给另一个activity我的问题课

public class Question {
    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();
       }

      }

Answer 1

步骤：

>

将对象类实现为可序列化

public class Question implements Serializable`

把这个放进你的来源activity

ArrayList<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", mQuestionList);

把这个放进你的目标activity

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

Answer 2

activity：为我工作

ArrayList<Object> object = new ArrayList<Object>();
Intent intent = new Intent(Current.class, Transfer.class);
Bundle args = new Bundle();
args.putSerializable("ARRAYLIST",(Serializable)object);
intent.putExtra("BUNDLE",args);
startActivity(intent);

在transfer.class中

Intent intent = getIntent();
Bundle args = intent.getBundleExtra("BUNDLE");
ArrayList<Object> object = (ArrayList<Object>) args.getSerializable("ARRAYLIST");

希望这个帮手是某人。

使用Parcelable在activity之间传递数据

这通常在创建了DataModel后起作用

例如，假设我们有一个类型为

{
    "bird": [{
        "id": 1,
        "name": "Chicken"
    }, {
        "id": 2,
        "name": "Eagle"
    }]
}

这里，bird是一个列表，它包含两个元素，所以

我们将使用jsonschema2pojo创建模型

现在我们有了模型类Name BirdModel和Bird BirdModel由Bird列表组成，Bird包含Name和id

转到bird类并添加接口“Implements Parcelable”

通过Alt+Enter在android studio中添加implemets方法

注意：会出现一个对话框，上面写着“添加实现方法”按Enter键

按Alt+Enter的add Parcelable实现

注意：会出现一个对话框，上面写着Add Parcelable implementation并再次输入

现在把它传给意图。

List<Bird> birds = birdModel.getBird();
Intent intent = new Intent(Current.this, Transfer.class);
Bundle bundle = new Bundle();
bundle.putParcelableArrayList("Birds", birds);
intent.putExtras(bundle);
startActivity(intent);

和转移activity onCreate

List<Bird> challenge = this.getIntent().getExtras().getParcelableArrayList("Birds");

谢谢

如果有什么问题请告诉我。