使用 android 中的可序列化将对象从第二个 activity 传递回主 activity

Question

下面的第一个代码块是我的主要 activity，我在其中创建了第二个 activity 的意图。在这个 activity 上，我在列表视图中显示了费用，现在我没有完全实现，因为它没有完全实现。我只是想做的是启动第二个 activity 并让用户输入详细信息并按下按钮将 activity 添加到列表视图。 @覆盖 public 布尔 onOptionsItemSelected（菜单项）{ 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 activity，用户在其中输入数据。当我尝试传回费用对象时，模拟器显示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 class 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，就无法说明您的问题。但是你可以通过这些点。 Serializable 方法的问题在于使用了反射，这是一个缓慢的过程。此方法创建大量临时对象并导致相当多的垃圾收集。所以，这可能是由于这个。在真实设备上尝试运行并查看它是否仍然存在。或者，您可以为 class 实现 Parcelable，这比 Serializable 更快。

使用 android 中的可序列化将对象从第二个 activity 传递回主 activity

Passing an object from the 2nd activity back to main activity using serializable in android

java

oop

android

object

serializable