尝试设置DataGridView列宽时"NullReferenceException",否则会带来数据

Question

我从存储过程中获取数据,这可以在datagrid中显示,但是设置列宽度会不断抛出空异常:

dataGridView2.Columns[x].Width = 60;

完整代码:

public void Populate_Data_Grid2_All()
    {
        string sqlQuery = "EXEC sp_CG_GMR_Select_Specific_Data";

        using (var connection = new SqlConnection(connectionString))
        using (var command = new SqlCommand(sqlQuery, connection))
        using (var adapter = new SqlDataAdapter(command))
        {
            connection.Open();
            var myTable = new DataTable();
            adapter.Fill(myTable);
            dataGridView2.DataSource = myTable;
        }

        dataGridView2.Columns[0].Width = 60;
        dataGridView2.Columns[0].ReadOnly = true;
        dataGridView2.Columns[1].Width = 40;
        dataGridView2.Columns[1].ReadOnly = true;
        dataGridView2.Columns[2].Width = 50;
        dataGridView2.Columns[2].ReadOnly = true;
        dataGridView2.Columns[3].Width = 250;
        dataGridView2.Columns[3].ReadOnly = true;
        dataGridView2.Columns[4].Width = 100;
        dataGridView2.Columns[4].ReadOnly = true;
        dataGridView2.Columns[4].DefaultCellStyle.Format = "N2";
    } 

设置ReadOnly和单元格样式不会抛出错误,但设置宽度会.此代码与我对程序中的另一个数据网格所做的完全相同,后者从不同的过程中引入了更多列.我正在尝试格式化的过程现在没有任何空白值或任何东西.

编辑: 为清楚起见,这里是其他数据网格执行相同的事情的代码完全正常.第二个数据网格也是第一个的副本,所以它的所有设置都是相同的(我也检查过以确保)

码:

public void Populate_Data_Grid1(string DataExists, string Scheme)
        {
            string NoCurrentPeriodData = "EXEC sp_CG_GMR_Scheme_Manual_Entry_Template @Scheme = '"+Scheme+"'";

            string YesCurrentPeriodData = "EXEC sp_CG_GMR_Current_Period_Data @Scheme = '"+Scheme+"'";

            string sqlQuery;

            if(DataExists())
            {
                sqlQuery = YesCurrentPeriodData;
            }
            else
            {
                sqlQuery = NoCurrentPeriodData;
            }

            using (var connection   = new SqlConnection(connectionString))
            using (var command      = new SqlCommand(sqlQuery, connection))
            using (var adapter      = new SqlDataAdapter(command))
            {
                connection.Open();
                var myTable = new DataTable();
                adapter.Fill(myTable);
                dg_Data1.DataSource = myTable;
            }

            //--Data Grid Column Properties--\\
            dg_Data1.Columns[0].Visible = false;
            dg_Data1.Columns[2].Visible = false;
            dg_Data1.Columns[4].Visible = false;
            dg_Data1.Columns[6].Visible = false;

            dg_Data1.Columns[1].Width = 60;
            dg_Data1.Columns[1].ReadOnly = true;
            dg_Data1.Columns[3].Width = 40;
            dg_Data1.Columns[3].ReadOnly = true;
            dg_Data1.Columns[5].Width = 50;
            dg_Data1.Columns[5].ReadOnly = true;
            dg_Data1.Columns[7].Width = 250;
            dg_Data1.Columns[7].ReadOnly = true;
            dg_Data1.Columns[8].Width = 100;
            dg_Data1.Columns[8].DefaultCellStyle.Format = "N2";
            //dg_Data1.Columns[8].DefaultCellStyle.Format = "D";

            btn_SaveValues.Enabled = true;

        }

Answer 1

我遇到了这个确切的问题,偶然发现在设置Width之前设置列的AutoSizeMode的不显眼的解决方案.例:

dataGridView2.Columns[0].AutoSizeMode = DataGridViewAutoSizeColumnMode.None;
dataGridView2.Columns[0].Width = 60;
dataGridView2.Columns[0].ReadOnly = true;