如何将项目添加到ListView

Question

I keep getting this error and I know why but I need help figuring out how I can solve it. The only way I have been able to add my items it to make a new form but that seems silly.

It wont work if I make all my methods static =(

I keep getting,

"An object reference is required for the non-static field, method, or property 'Handicap_Calculator.FormMain.listViewLog' \\Form1.cs 74 13 Handicap Calculator"

Here´s my code:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace Handicap_Calculator
{

public partial class FormMain : Form
{
    //FormAddScore FormAddNewScore = new FormAddScore();
    public static bool addScoreIsShown = false;
    public static FormAddScore _FormAddScore;
    public static ListViewItem Item;
    //public static List<string> ScoreInfo = new List<string>();

    public FormMain()
    {
        InitializeComponent();

    }

    public void button1_Click(object sender, EventArgs e)
    {
        try
        {
            if (_FormAddScore == null || _FormAddScore.IsDisposed)
            {
                _FormAddScore = new FormAddScore();
            }
            _FormAddScore.Show();
            if (_FormAddScore.WindowState == FormWindowState.Minimized)
            {
                _FormAddScore.WindowState = FormWindowState.Normal;
            }
            _FormAddScore.BringToFront();
        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.ToString());
        }
    }

    public static void AddScore()
    {
        int Round = 1;
        DateTime date = _FormAddScore.date;
        string course = _FormAddScore.course;
        int holes = _FormAddScore.holes;
        int score = _FormAddScore.score;
        float courseRating = _FormAddScore.courseRating;
        float slopeRating = _FormAddScore.slopeRating;

        string[] ScoreInfo = new string[7];
        ScoreInfo[0] = Round.ToString();
        ScoreInfo[1] = date.ToString();
        ScoreInfo[2] = course;
        ScoreInfo[3] = holes.ToString();
        ScoreInfo[4] = score.ToString();
        ScoreInfo[5] = courseRating.ToString();
        ScoreInfo[6] = slopeRating.ToString();
        AddToList(ScoreInfo);

    }

    public static void AddToList(string[] ScoreInfo)
    {
        Item = new ListViewItem(ScoreInfo);            
        //listViewLog.Items.Add(Item);      

    }

}
}

Edit...

Here is the class im calling it from:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace Handicap_Calculator
{

public partial class FormAddScore : Form
{
    public DateTime date;
    public string course;
    public int holes;
    public int score;
    public float courseRating;
    public float slopeRating;

    public FormAddScore()
    {
        InitializeComponent();

    }

    private void FormAddScore_FormClosing(object sender, FormClosingEventArgs e)
    {
        FormMain.addScoreIsShown = false;
    }

    public void  getscore()
    {
        try
        {
            date = dateTimePicker1.Value;
            course = textBoxCourse.Text;
            holes = Convert.ToInt16(textBoxHoles.Text);
            score = Convert.ToInt16(textBoxScore.Text);
            courseRating = Convert.ToSingle(textBoxCourseRating.Text);
            slopeRating = Convert.ToSingle(textBoxSlopeRating.Text);
        }
        catch(Exception ex)
        {
            MessageBox.Show(ex.ToString());
        }
    }

    private void button1_Click(object sender, EventArgs e)
    {
        getscore();            
        FormMain.AddScore();
    }
}
}

Answer 1

The simple solution is to define your methods AddScore and AddToList as non-static.

public void AddScore()
{
    //your code
}

public void AddToList(string[] ScoreInfo)
{
    // your code
}

If you want to use static methods you should pass the instance of your Form to the method, on which you want to add items to the ListView.

public static void AddScore(FormMain mainForm)
{
    //your code
    AddToList(mainForm, ScoreInfo);
}

public static void AddToList(FormMain mainForm, string[] ScoreInfo)
{
    // your code
}

Update:

According to your updated code the solution is to pass the instance of your FormMain to your FormAddScore when you create it. In FormAddScore you store the reference to the FormMain instance to call the methods on.

public partial class FormAddScore : Form
{
  // your code

  private FormMain _mainForm;

  public FormAddScore(){
    InitializeComponent();

  }

  public FormAddScore(FormMain mainForm) : this(){
    _mainForm = mainForm;
  }

In your FormMain when you create the instance of FormAddScore you should use the constructor that expects an instance of FormMain

 _FormAddScore = new FormAddScore(this);

With this setup you can change your methods to non-static and you can call the methods of FormMain in your FormAddScore, by using the stored reference in variable _mainForm.

 _mainForm.AddScore();