Question

我想通过按student.FirstName从studentsList输出每个btnNext_Click，从0值开始到最后一个，点击“下一步按钮”。我尝试这样做，但是，不知道如何从public static List<Student> studentsList = new List<Student>();

输出正确的值

private void btnCreateStudent_Click(object sender, RoutedEventArgs e)
{
    addStudent();
    Clear();
}

private void btnNext_Click(object sender, RoutedEventArgs e)
{
    Next();
}

public void addStudent()
{
    Student student = new Student();
    student.FirstName = txtFirstName.Text;
    student.LastName = txtLastName.Text;
    student.City = txtCity.Text;
    Student.studentsList.Add(student);
}

public void Clear()
{
    txtFirstName.Clear();
    txtLastName.Clear();
    txtCity.Clear();
}

public void Next()
{
    foreach (Student student in Student.studentsList)
    {
        txtFirstName.Text = student.FirstName;
    }
}

Answer 1

使用变量存储学生的索引，并在每次按下时增加一次，这样每次都会获得下一个学生姓名。

例如：

int studentIndex;
public void Next()
{
     if (studentIndex >= Student.studentsList.Count - 1)
         studentIndex = 0;
     txtFirstName.Text = Student.studentsList[studentIndex].FirstName;
     studentIndex++;
}

到达最后一名学生后，它将重置为第一名学生。

Answer 2

您需要将当前状态保留在程序中，以便实现＆＃34;步进＆＃34;像那样。您只需要当前索引：在构造函数中初始化它，然后在Next方法中使用它。完成当前索引后，将其递增，以便下次调用Next方法时获得后续值。

int currentStudent = 0;
public void Clear() {
    txtFirstName.Clear();
    txtLastName.Clear();
    txtCity.Clear();
    currentStudent = 0;
}
public void Next() {
    // You need to stop when you reach the end of the list
    if (currentStudent < Student.studentsList.Count) {
        txtFirstName.Text = Student.studentsList[currentStudent].FirstName;
        currentStudent++;
    }
}

Answer 3

尝试将最后一个索引作为类成员存储。

int lastIndexRead = 0;
public void Next()
{
    if(lastIndexRead == Student.studentsList.Count) // do something - index is out of bounds of the array
    else
    {
       txtFirstName.Text = Student.studentsList[lastIndexRead].FirstName;
       lastIndexRead++;
   }
}

从List＆lt;＆gt;输出值

3 个答案: