从另一个类C＃添加列表框项

Question

大家好我正在尝试将另一个类的值添加到MainForm上的ListBox但是我收到错误NullReferenceException未处理。这是我的代码：

public partial class MainForm : Form
{      
    Seats currentSeat = new Seats();

    public MainForm()
    {
        InitializeComponent(); // VS' s code

        //1. Prepare the form before it is shown to the user.
        InitializeGUI();
    }

    private void InitializeGUI()
    {           
        currentSeat.Seat();
    }

**class Seats**
{

    private string customerName = "Me ";

    MainForm mainForm;

    public void Seat()
    {
      SetDefaultValues();
    }

  private void  SetDefaultValues(){

      for (int seat = 1; seat <= 60; seat++)
      {            
          mainForm.listBoxReservations.Items.Add(string.Format("{0} {1} ", seat,costumerName)); // **HERE IS THE ERROR NullReferenceException was unhandled**

      }

    }
}

任何建议

Answer 1

您尚未创建MainForm类 AND 拼写错误的customerName：

private void SetDefaultValues（）{

  for (int seat = 1; seat <= 60; seat++)
  {            
      mainForm.listBoxReservations.Items.Add(string.Format("{0} {1} ",    seat,costumerName)); // **HERE IS THE ERROR NullReferenceException was unhandled**

  }

您的实例变量说明了这一点：

 private string customerName = "Me ";

但是你的代码引用了这个：

costumerName