Question

我的Arraylist只存储一个对象。每次输入新对象时，它都会覆盖当前对象。

通话方式：

    public void saveBookingInfo(View view) {

    EditText applicantNameText = (EditText) findViewById(R.id.applicantNameTextField);
    EditText itemToBurnText = (EditText) findViewById(R.id.itemToBurnTextField);

    String appName = applicantNameText.getText().toString();
    String appItemToBurn = itemToBurnText.getText().toString();

    if (appItemToBurn.isEmpty() || appName.isEmpty()) {
        Toast.makeText(BookingScreen.this, "Please fill in all fields.", Toast.LENGTH_SHORT).show();
    }
    else {
        sendApplication.storeApplication(appName, appItemToBurn);
        this.finish();
    }
}

ArrayList方法：

  public void storeApplication(String name, String item){
    ArrayList<Application> peopleAttending = new ArrayList<>(10);
    peopleAttending.add(new Application(name, item));
}

Answer 1

您将List<Application>声明为方法的本地参数。将其作为类中的字段移动。

private List<Application> peopleAttending = new ArrayList<>();

public void storeApplication(String name, String item) {
    peopleAttending.add(new Application(name, item));
}

Answer 2

每次调用方法时，都会创建一个new ArrayList。您应该只创建一次ArrayList并传递对该方法的引用，或者将引用作为实例变量。

Answer 3

您可以尝试更改对象sendApplication

的类的构造函数

class SendApplication{
    List<Application> peopleAttending = null;
    public SendApplication(){
        List<Application> peopleAttending = new ArrayList<Application>();
    }
    public void storeApplication(String name, String item) {
        peopleAttending.add(new Application(name, item));
    } //...... other methods follow
}

ArrayList仅存储一个对象

3 个答案: