Question

我有一个名为 AddEditReminderForm 的抽象窗体，其中包含一个事件处理程序和一个方法：

buttonSave_Click
PerformValidations

以下是 AddEditReminderForm 的相关代码：

protected virtual void buttonSave_Click(object sender, EventArgs e)
{
    title = textboxTitle.Text;
    description = textboxDescription.Text;
    place = textboxPlace.Text;
    date = datePicker.Value.Date;
    time = timePicker.Value.TimeOfDay;

    PerformValidations();
}

protected void PerformValidations()
{
    if (String.IsNullOrEmpty(title))
    {
        MessageBox.Show("Error: The title field was left empty!");
        return;
    }

    if (String.IsNullOrEmpty(description))
    {
        MessageBox.Show("Error: The description field was left empty!");
        return;
    }

    if (String.IsNullOrEmpty(place))
    {
        MessageBox.Show("Error: The place field was left empty!");
        return;
    }

    if (date < currentDate)
    {
        MessageBox.Show("Error: The date must be in the future!");
        return;
    }

    if (date == currentDate && time < currentTime)
    {
        MessageBox.Show("Error: The time must be in the future!");
        return;
    }
}

然后我有一个名为 AddReminderForm 的表单，它继承自 AddEditReminderForm 。我正在覆盖 buttonSave_Click 事件处理程序，以便除了在基类中执行的正常操作之外还保存提醒。以下是 AddReminderForm 的代码：

using System;
using System.Windows.Forms;
using Reminder.Classes;

namespace Reminder
{
    public partial class AddReminderForm : AddEditReminderForm
    {
        public AddReminderForm()
        {
            InitializeComponent();
            this.Text = "Add Reminder Form";

            Label labelFormHeading = this.Controls["labelFormHeading"] as Label;
            labelFormHeading.Text = "Add Reminder";
        }

        protected override void buttonSave_Click(object sender, EventArgs e)
        {
            base.buttonSave_Click(sender, e);
            AddReminderOperation();
        }

        protected void AddReminderOperation()
        {
            ReminderClass reminder = new ReminderClass();
            reminder.Id = ReminderHelper.GetCounter();
            reminder.Title = title;
            reminder.Description = description;
            reminder.Place = place;
            reminder.Date = date;
            reminder.Time = time;

            ReminderHelper.AddReminder(reminder);
            MessageBox.Show("The reminder has been successfully saved!");
            this.Close();
        }
    }
}

现在，我遇到的问题是，当 AddReminderForm 打开时，如果 PerformValidations 方法中的某个验证失败，则会显示消息框但执行没有停止，提醒仍然保存。如果其中一个验证失败，我该如何中断执行？我正在使用return，但如果我没记错，return只会停止执行当前方法。感谢。

Answer 1

我会在您的基类ValidateAndSave中创建一个方法，该方法从事件处理程序调用：

protected void ValidateAndSave()
{
    if (this.PerformValidations())
    {
        this.Save();
    }
}

private void buttonSave_Click(object sender, EventArgs e)
{
    this.ValidateAndSave();
}

protected bool PerformValidations()
    /* could be virtual, if you want to do additional checks in derived classes */
{ ... }

protected virtual void Save()
{ ... }

如果所有验证都可以，则PerformValidations会返回true。然后调用save，您可以在派生类中覆盖它。

Windows窗体 - 如何中断当前正在执行的代码的执行

1 个答案: