檢查datagridview單元格中的數據是否為空

Question

我的DataGridView通過SqlDataReader綁定到數據庫查詢結果，當我測試單元格值為null ，我得到了意外的結果。

我的代碼是這樣的：

SqlConnection con = new SqlConnection(
     "Data Source = .;Initial Catalog = SAHS;integrated security = true");
con.Open();
SqlCommand cmd3 = new SqlCommand(
    "select  Status from vw_stdtfeedetail 
     where Std= 6  and Div ='B' and name='bbkk' and mnthname ='June'", con);
SqlDataReader dr = cmd3.ExecuteReader();
BindingSource bs = new BindingSource();
bs.DataSource = dr;
dataGridView3.DataSource = bs;
this.monthFeeTableAdapter.Fill(this.sAHSDataSet4.MonthFee);
if (dataGridView3.CurrentCell.Value == null)
{
    MessageBox.Show("Pending");
}
else
{
    MessageBox.Show("Already Paid");
}

即使數據庫中的值為null，我仍將獲得輸出Already Paid 。

Answer 1

嘗試使用DBNull.Value而不是null

if (dataGridView3.CurrentCell.Value == DBNull.Value)
{
    MessageBox.Show("Pending");
}
else
{
    MessageBox.Show("Already Paid");
}