“row”参数不能为空。参数名称：row

Question

I am trying to load back values from a CSV to my class . Then display the values to my datatable . However, I get the error even after my values have been loaded into the class and placed inside the intended columns (See Figure 1 ). The error occurred at dt.Rows.Add(dr); . Below is my code:

 public Newdatagrid()
    {
        InitializeComponent();

        //Do datatable
        ds = new DataSet();
        dt = new DataTable();
        dt.Columns.Add("Bus Model", typeof(string));//0
        dt.Columns.Add("Bus Type", typeof(string));//1
        dt.Columns.Add("Mileage", typeof(string));//2

        if (Savestate.vehnochange_list.Count > 0)
        {
            foreach (DataRow dr in dt.Rows)
            {
                dr["Bus Model"] = Savestate.busmodel_list[Savestate.busmodel_list.Count];//0
                dr["Bus Type"] = Savestate.bustype_list[Savestate.bustype_list.Count];//1
                dr["Mileage"] = Savestate.busmileage_list[Savestate.busmileage_list.Count];//2
            }

            dt.Rows.Add(dr);
            this.dataGridView2.DataSource = dt;

        }
   }

Answer 1

I think you want something like this:

public Newdatagrid()
{
    InitializeComponent();

    //Do datatable
    ds = new DataSet();
    dt = new DataTable();
    dt.Columns.Add("Bus Model", typeof(string));//0
    dt.Columns.Add("Bus Type", typeof(string));//1
    dt.Columns.Add("Mileage", typeof(string));//2

    if (Savestate.vehnochange_list.Count > 0)
    {
        for (int i=0; i < Savestate.vehnochange_list.Count; ++i)
        {
            DataRow dr = dt.NewRow();
            dr["Bus Model"] = Savestate.busmodel_list[i];//0
            dr["Bus Type"] = Savestate.bustype_list[i];//1
            dr["Mileage"] = Savestate.busmileage_list[i];//2
            dt.Rows.Add(dr);
        }

        this.dataGridView2.DataSource = dt;

    }
}