我的问题是这样的：我有一个带有datagridview的C＃应用程序，它的列中有一些文本框和组合框 . 所有列都从数据库中获取数据 . 文本框是只读的 . 当我要求每行中的值时，我得到最后选择的组件的值（即组合框的值，因为文本框是只读的）为null .
例如：
我连续有10个细胞 . 组合框是连续的第7，第8和第9个索引，其中0到6的索引是texbox . 当我选择其中的3个（按7,8,9的顺序）时，我无法获得9的单元格值 .
row.Cells[7].Value 没问题， row.Cells[8].Value 没问题， row.Cells[9].Value 是 null
当我选择其中任何两个时，先说8然后再说7，我就不能得到7的单元格值 .
row.Cells[8].Value 没问题 row.Cells[7].Value 是 null
当我只选择一个项目时说9，我再次获得单元格值为null .
因此，我将最后选择的DataGridViewComboBoxCell作为null .
有人可以帮我解决我的问题吗？感谢你的帮助 .
这是我的代码：
private void cmbVariable_SelectedIndexChanged(object sender, EventArgs e)
{
ComboBox cmb = sender as ComboBox;
BringQuery(cmb.SelectedItem.ToString());
}
private void BringQuery(string option)
{
SqlConnection conn = new SqlConnection("Server = 10.2.6.14; Database = TTS; uid = myuser; password = mypassword");
DataTable dt1 = new DataTable();
SqlCommand cmd1 = new SqlCommand("select Track_Number, Parking_Area, Mission_Number, Track_Info, Time, Direction, Explanation from Traffic_Run_Table where Op_Type=@myType", conn);
SqlCommand cmd2 = new SqlCommand("select * from Traffic_Track_Table", conn);
SqlCommand cmd3 = new SqlCommand("select * from Traffic_Driver order by Id_Number", conn);
SqlDataAdapter sda1 = new SqlDataAdapter(cmd1);
cmd1.Parameters.Add(new SqlParameter("myType", option));
try
{
conn.Open();
sda1.Fill(dt1);
dataGridView2.AutoGenerateColumns = false;
foreach (DataGridViewColumn col in dataGridView2.Columns)
{
col.DataPropertyName = col.Name;
}
dataGridView2.DataSource = dt1;
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
DataGridViewComboBoxColumn cmbCol1, cmbCol2, cmbCol3;
SqlDataAdapter sda2 = new SqlDataAdapter(cmd2);
DataTable dt2 = new DataTable();
try
{
cmbCol1 = new DataGridViewComboBoxColumn();
cmbCol1.HeaderText = "Track 1";
cmbCol1.Name = "Track1";
cmbCol1.DataPropertyName = cmbCol1.Name;
cmbCol1.ValueType = typeof(int);
cmbCol1.Width = 50;
cmbCol2 = new DataGridViewComboBoxColumn();
cmbCol2.HeaderText = "Track 2";
cmbCol2.Name = "Track2";
cmbCol2.DataPropertyName = cmbCol2.Name;
cmbCol2.ValueType = typeof(int);
cmbCol2.Width = 50;
sda2.Fill(dt2);
dt2.Columns[0].ColumnName = "Track";
foreach (DataRow dr in dt2.Rows)
{
cmbCol1.Items.Add(Convert.ToInt32(dr["Track"]));
cmbCol2.Items.Add(Convert.ToInt32(dr["Track"]));
}
dataGridView2.Columns.Add(cmbCol1);
dataGridView2.Columns.Add(cmbCol2);
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
SqlDataAdapter sda3 = new SqlDataAdapter(cmd3);
DataTable dt3 = new DataTable();
try
{
cmbCol3 = new DataGridViewComboBoxColumn();
cmbCol3.HeaderText = "Driver";
cmbCol3.Name = "Driver";
cmbCol3.DataPropertyName = cmbCol3.Name;
cmbCol3.ValueType = typeof(string);
cmbCol3.Width = 260;
sda3.Fill(dt3);
dt3.Columns[0].ColumnName = "Id";
dt3.Columns[1].ColumnName = "Driver";
dt3.Columns[2].ColumnName = "Mission";
foreach (DataRow dr in dt3.Rows)
{
cmbCol3.Items.Add(Convert.ToString(dr["Id"]).Trim() + " - " + Convert.ToString(dr["Dirver"]).Trim() + " - " + Convert.ToString(dr["Mission"]).Trim());
}
dataGridView2.Columns.Add(cmbCol3);
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
conn.Close();
}
public string CheckNull(object value, Type objType)
{
string retVal = string.Empty;
if (value == null || value.ToString() == " " || value.ToString() == "")
{
if (objType == typeof(int))
{
retVal = "0";
}
if (objType == typeof(string))
{
retVal = "-";
}
}
else
{
retVal = value.ToString();
}
return retVal;
}
private void Save_Click(object sender, EventArgs e)
{
SqlConnection connForSave = new SqlConnection("Server = 10.2.6.14; Database = TTS; uid = myuser; password = mypassword");
SqlCommand cmdForSave = new SqlCommand("insert into Traffic_Records values (@type, @trackNumber, @parkingArea, @missionNmb, @trackInfo, @time, @direction, @explanation, @track1, @track2, @driverId, @driverName, @driverMission, @date)", connForSave);
foreach (DataGridViewRow row in dataGridView2.Rows)
{
try
{
dataGridView2[7, row.Index].Selected = false;
dataGridView2[8, row.Index].Selected = false;
dataGridView2[9, row.Index].Selected = false;
connForSave.Open();
cmdForSave.Parameters.AddWithValue("type", CheckNull(cmbVairable.SelectedItem.ToString(), typeof(string)));
cmdForSave.Parameters.AddWithValue("trackNumber", Convert.ToInt16(CheckNull(row.Cells[0].Value, typeof(int))));
cmdForSave.Parameters.AddWithValue("parkingArea", CheckNull(row.Cells[1].Value, typeof(string)));
cmdForSave.Parameters.AddWithValue("missionNmb", Convert.ToInt16(CheckNull(row.Cells[2].Value, typeof(int))));
cmdForSave.Parameters.AddWithValue("trackInfo", CheckNull(row.Cells[3].Value, typeof(string)));
cmdForSave.Parameters.AddWithValue("time", CheckNull(row.Cells[4].Value, typeof(string)));
cmdForSave.Parameters.AddWithValue("direction", CheckNull(row.Cells[5].Value, typeof(string)));
cmdForSave.Parameters.AddWithValue("explanation", CheckNull(row.Cells[6].Value, typeof(string)));
cmdForSave.Parameters.AddWithValue("track1", Convert.ToInt16(CheckNull(row.Cells[7].Value, typeof(int))));
cmdForSave.Parameters.AddWithValue("track2", Convert.ToInt16(CheckNull(row.Cells[8].Value, typeof(int))));
string[] sArray = null;
if (string.Compare(CheckNull(row.Cells[9].Value, typeof(string)), "0") != 0 && string.Compare(CheckNull(row.Cells[9].Value, typeof(string)), "-") != 0)
{
sArray = row.Cells[9].Value.ToString().Split('-');
sArray[0] = sArray[0].Remove(sArray[0].Length - 2, 1);
sArray[1] = sArray[1].Remove(0, 1);
sArray[1] = sArray[1].Remove(sArray[1].Length - 2, 1);
sArray[2] = sArray[2].Remove(0, 1);
}
else
{
string temp = "0 - -";
sArray = temp.Split(' ');
}
cmdForSave.Parameters.AddWithValue("driverId", Convert.ToInt16(sArray[0]));
cmdForSave.Parameters.AddWithValue("driverName", sArray[1]);
cmdForSave.Parameters.AddWithValue("driverMission", sArray[2]);
cmdForSave.Parameters.AddWithValue("date", DateTime.Now);
cmdForSave.ExecuteNonQuery();
cmdForSave.Parameters.Clear();
}
catch (Exception ex)
{
MessageBox.Show(ex.Message + "\n Line Number: " + ex.LineNumber());
}
connForSave.Close();
}
}
1 回答
发生这种情况是因为
DataGridView不会立即提交用户所做的更改，但只有在验证了行之后（我认为，这里可能是错误的） . 因此，在选择最后一个值并且未更改行（因此未触发validate事件）后，组合框中的值仍为空 .要解决这个问题，请添加
CurrentCellDirtyStateChanged（此处更多信息MSDN事件到您的网格：这就是为什么新的 Value 观会立即发生的原因 .