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

Question

我的onClick()方法中的代码如下 List<Question> mQuestionsList = QuestionBank.getQuestions();现在，我有这行之后的意图，如下所示：  Intent resultIntent = new Intent(this, ResultActivity.class);  resultIntent.putParcelableArrayListExtra("QuestionsExtra", (ArrayList<? extends Parcelable>) mQuestionsList);  startActivity(resultIntent);我不知道如何在意图中将此问题列表从一个活动传递到另一个活动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;    }

Answer 1

活动之间：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");

希望这个帮助的人。

使用Parcelable在Activity之间传递数据

创建DataModel后，通常可以使用

例如，假设我们有一个json类型

{

    "bird": [{

        "id": 1,

        "name": "Chicken"

    }, {

        "id": 2,

        "name": "Eagle"

    }]

}

这里的鸟是一个列表，它包含两个元素，因此

我们将使用jsonschema2pojo创建模型

现在我们有了包含Bird of List的模型类Name BirdModel和Bird BirdModel，并且Bird包含名称和ID

转到bird类并添加接口“ 实现Parcelable ”

通过Alt + Enter在android studio中添加implemets方法

注意：将出现一个对话框，提示添加工具方法，然后按Enter

通过按Alt + Enter添加Parcelable实现

注意：将出现一个对话框，显示“添加可打包实施并再次输入”

现在将其传递给意图。

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);

并在转移活动onCreate

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

谢谢

如果有任何问题，请告诉我。

Answer 2

脚步：

将您的对象类实现为可序列化

public class Question implements Serializable`

将此放到您的源活动中

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);

将此放入您的目标活动中

 ArrayList<Question> questions = new ArrayList<Question>();

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

Answer 3

效果很好

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();

     }

  }

在您的“源活动”中，使用以下命令：

  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);

在您的目标活动中，使用以下命令：

  List<Question> questions = new ArrayList<Question>();

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