尝试将datable从一个表单传递到另一个表单时获取Null引用异常

Question

我正在尝试将数据从一种形式传递到另一种形式。已从数据库成功检索数据，但程序在设备上部署时抛出Null引用异常错误。 我的代码

form 1：

if (comboBox1.SelectedItem.ToString() == "Select by Picture")
            {
                MySqlConnection con = new MySqlConnection("server=******;port= *****;database=********;User Id=root;Password=;");
                MySqlDataAdapter d_a = new MySqlDataAdapter("Select Picture From sampledata", con);
                DataTable d_t = new DataTable();
                d_a.Fill(d_t);
                int count = d_t.Rows.Count;
                PictureSelection ps = new PictureSelection();
                if (count > 0)
                ps.Storelist.Items.Clear();
                for (int i=0 ; i <count; i++)
                {
                    ps.Storelist.Items.Add(d_t.Rows[i][0].ToString());
                }
                ps.ShowDialog();
            }
            else if (comboBox1.SelectedItem.ToString() == "Select by Artist Name")
            {
                MySqlConnection con = new MySqlConnection("server=*****;port= ****;database=*****;User Id=root;Password=;");
                MySqlDataAdapter d_a = new MySqlDataAdapter("Select Artist Name From sampledata", con);
                DataTable d_t = new DataTable();
                d_a.Fill(d_t);
                int count = d_t.Rows.Count;
                PictureSelection ps = new PictureSelection();
                if (count > 0)
                ps.Storelist.Items.Clear();
                for (int i = 0; i < count; i++)
                {
                    ps.Storelist.Items.Add(d_t.Rows[i][0].ToString());
                }
                ps.ShowDialog();
            }
        }

Form2：

private void PictureSelection_Load(object sender, EventArgs e)
        {

            Storelist.DataSource = mainmn.d_t;


        }

任何帮助将不胜感激。

Answer 1

您必须从form1：

设置数据表

ps.Storelist.Datasource = d_t;
ps.ShowDialog();

因为form2没有datatable的定义，所以发生错误。