使用android中的可序列化将对象从第二个活动传递回主要活动

Question

下面的第一个代码块是我的主要活动，我在其中创建了第二个活动的意图。在这个活动中，我在一个列表视图中显示了费用，由于它没有完全实现，所以现在我已经忽略了。我想做的是启动第二个活动，让用户输入详细信息并按下按钮将活动添加到列表视图。 @覆盖 public boolean onOptionsItemSelected(MenuItem item) { int id = item.getItemId();

        if (id == R.id.addExpense) {
            Intent intent = new Intent(this, ExpenseActivity.class);
            startActivityForResult(intent, 1);
            return true;
        }
        return super.onOptionsItemSelected(item);
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    // check that it is the SecondActivity with an OK result
    if (requestCode == 1) {
        if (resultCode == RESULT_OK) {
            Expense expense = (Expense) data.getSerializableExtra("sampleObject");
            Expenses.add(expense);
        }
    }
}


 final Button btnAddExpense = (Button) findViewById(R.id.btnAddExpense);
    btnAddExpense.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
           String amountV = txtAmountVat.getText().toString();
           int amountVTwo = Integer.parseInt(amountV);
           String amountI = txtAmount.getText().toString();
           int amountITwo = Integer.parseInt(amountI);

            Expense expense = new Expense(amountITwo, amountVTwo, txtDateOfExpense.getText().toString(), txtDateAdded.getText().toString(), datePaid, paid, txtDes.getText().toString(), imageUri );

            Intent intent = new Intent();
            intent.putExtra("Expense", expense);
            setResult(MainActivity.RESULT_OK, intent);
            finish();
        }
        });

这是我的第二个用户输入数据的活动。当我尝试传回费用对象时，模拟器状态应用程序已停止工作。请给我一些帮助，因为我不知道是什么导致了这个问题。这就是我的班级的样子。

public class Expense implements Serializable {

private int _amount, _amountVat;
private String _dateOfExpense, _dateAdded, _datePaid, _expenseDescription;
private Boolean _paid;
private Uri _imageUri;

public Expense(int amount, int amountVat, String dateOfExpense, String dateAdded, String datePaid, Boolean paid, String expenseDescription, Uri imageUri){

    _amount = amount;
    _amountVat = amountVat;
    _dateOfExpense = dateOfExpense;
    _dateAdded = dateAdded;
    _datePaid = datePaid;
    _paid = paid;
    _expenseDescription = expenseDescription;
    _imageUri = imageUri;
}

public int get_amount() {
    return _amount;
}

public void set_amount(int _amount) {
    this._amount = _amount;
}

public int get_amountVat() {
    return _amountVat;
}

public void set_amountVat(int _amountVat) {
    this._amountVat = _amountVat;
}

public String get_dateOfExpense() {
    return _dateOfExpense;
}

public void set_dateOfExpense(String _dateOfExpense) {
    this._dateOfExpense = _dateOfExpense;
}

public String get_dateAdded() {
    return _dateAdded;
}

public void set_dateAdded(String _dateAdded) {
    this._dateAdded = _dateAdded;
}

public String get_datePaid() {
    return _datePaid;
}

public void set_datePaid(String _datePaid) {
    this._datePaid = _datePaid;
}

public Boolean get_paid() {
    return _paid;
}

public void set_paid(Boolean _paid) {
    this._paid = _paid;
}

public Uri get_imageUri() {
    return _imageUri;
}

public void set_imageUri(Uri _imageUri) {
    this._imageUri = _imageUri;
}

public String get_expenseDescription() {return _expenseDescription;}

public void set_expenseDescription(String _expenseDescription) {this._expenseDescription = _expenseDescription;}

}

Answer 1

如果没有适当的日志详细信息，您的问题就无从谈起。 但是你可以通过这些点。 Serializable 方法的问题在于使用了反射，而且这是一个缓慢的过程。这种方法会创建很多临时对象并导致相当多的垃圾收集。所以，可能是因为这个。尝试在真实设备上运行并查看它是否仍然存在。 或者，您可以为您的类实现 Parcelable，它比 Serializable 更快。