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ComboBox DataBinding C# WinForms

I have 2 Tables:
Diagnose: ID, Name
DiagnoseForPatients: PatientID, DiagnoseID.
I have A DateGridView with 2 ComboBoxes: First ComboBox needs to show the ID of the Diagnose, And the second one needs to show the name.
When I'm adding a new row to my DataGridView I'm Getting an Exception saying DiagnoseID Can't be null (although I chose ID On first ComboBox).
I'm using this code to add the ComboBox's to my DataGridView:
ClinicTableAdapters.DiagnoseTableAdapter daDiagnoses = new ClinicTableAdapters.DiagnoseTableAdapter();
Clinic.DiagnoseDataTable dtDiagnosesAdd = daDiagnoses.GetData();
DgDiagnosesAdd.AutoGenerateColumns = false;
col1.HeaderText = "ID";
col1.DataPropertyName = "ID";
col1.Name = "ID";
col1.ValueMember = "ID";
col1.DisplayMember = "ID";
col1.DataSource = dtDiagnosesAdd;
DgDiagnosesAdd.Columns.Add(col1);
col2.HeaderText = "Name";
col2.DataPropertyName = "Name";
col2.Name = "Name";
col2.ValueMember = "Name";
col2.DisplayMember = "Name";
col2.DataSource = dtDiagnosesAdd;
DgDiagnosesAdd.Columns.Add(col2);
I'm using the DataGridView For Adding Diagnoses For patient. The DataGridView Is binded to DiagnosesForPatients DataTable.
How can I bind the DiagnoseID?
ON WPF VB.NET I use:
cmb.SelectedValueBinding = New Binding("DiagnoseID")
How should I Write it on WinForms?

One column is enough for handling "Diagnose" information
DgDiagnosesAdd.AutoGenerateColumns = false;
col1.HeaderText = "Diagnose";
//Next line will bind DiagnoseForPatients.DiagnoseID to Diagnose.ID
col1.DataPropertyName = "DiagnoseID";
col1.Name = "DiagnosesDiagnoseID";
col1.ValueMember = "ID";
col1.DisplayMember = "Name"; //Name column will be used as display text
col1.DataSource = dtDiagnosesAdd;
DgDiagnosesAdd.Columns.Add(col1);
About Exception saying DiagnoseID Can't be null
Seems like DiagnoseID column's property AllowDbNull = false.
Set DataColumn.AllowDbNull = true
Or set DataColumn.DefaultValue = 1 or some other default value for column
If you haven't access to the DataTable's column, then you can set default values for new rows in the DataGridView1.DefaultValuesNeeded eventhandler
private void DataGridView1_DefaultValuesNeeded(Object sender, DataGridViewRowEventArgs e)
{
int comboBoxColumnIndex = 1;
int diagnoseIDDefaultValue = 1;
e.Row.Cells[ComboBoxColumnIndex].Value = diagnoseIDDefaultValue;
}

Binding DataGridViewComboBoxColumn to DataTable is not working

I am binding DataGridViewComboBoxColumn to DataTable, but the the cells of the column are not displaying the bound table.
any idea?
to test the DataTable, I bound it to a normal ComboBox and this shows the expected behavior.
private void populateDataGW()
{
int addressesCount = data.Length / 186;
TestingAdrress[] addressArray = new TestingAdrress[addressesCount];
addressArray = getArray();
DataGridViewRow dtRow = new DataGridViewRow();
dtTableCmbBx = getAllCustomers();
DataGridViewComboBoxColumn cmBxCol = new DataGridViewComboBoxColumn();
//Binding here is not working
cmBxCol.DataSource = dtTableCmbBx;
cmBxCol.ValueMember = "Customer_ID";
cmBxCol.DisplayMember = "Name";
dtGrViTestAddress.Columns.Add(cmBxCol);
//code for "normal" combobox
comboBox1.DataSource = dtTableCmbBx;
comboBox1.DisplayMember= "Name";
comboBox1.ValueMember = "Customer_ID";
DataGridViewButtonCell btnCell = new DataGridViewButtonCell();
btnCell.Value = "Hinzufügen";
for (int i=0; i< addressArray.Length;i++)
{
dtGrViTestAddress.Rows.Add();
dtGrViTestAddress.Rows[i].Cells[0].Value = addressArray[i].Name;
dtGrViTestAddress.Rows[i].Cells[1].Value = addressArray[i].Street;
dtGrViTestAddress.Rows[i].Cells[2].Value = addressArray[i].PostalCode;
dtGrViTestAddress.Rows[i].Cells[3].Value = addressArray[i].City;
dtGrViTestAddress.Rows[i].Cells[5] = btnCell;
}
}
Here is a screenshot:

i found the problem. i wanted the datagridview to be readOnly, so thats why the combobox didnt show the items in it, now i changed this property, and i set it for each column separated, and let the comboboxcolumn to be readOnly=false

Method 1: Use Linq
var details = (from x in db.Details
orderby x.Datetime descending
where x.RaisedBy == "xyz"
select x).ToList();
comboBox1.ValueMember ="id";
comboBox1.DataSource = details;
comboBox2.ValueMember ="Name";
comboBox2.DataSource = details;
comboBox3.ValueMember ="Street";
comboBox3.DataSource = details;
comboBox4.ValueMember ="PostalCode";
comboBox4.DataSource = details;
Method :2
var combocolumnA = new DataGridViewComboBoxColumn();
combocolumnA.HeaderText = "ID"; // grid header name
combocolumnA.ValueMember = "id";// database Column name
combocolumnA.DataSource = details;
GV.Columns.Add(combocolumnA);
combocolumnA.Width = 100;
var combocolumnB = new DataGridViewComboBoxColumn();
combocolumnB.HeaderText = "Name";
combocolumnB.ValueMember = "Name";
combocolumnB.DataSource = details;
GV.Columns.Add(combocolumnB);
combocolumnB.Width = 150;
Edit:
Just to tell you one more thing... If you want the data in grid view suppose when you select name from combo box then data automatically change all fields of gridview according to database ?

How to populate the DataGridViewComboBoxColumn

I have DataGridViewComboBoxColumn in my datagridview and I want to populate using linq in run-time:
I try this
var line = from li in dbdata.Production_lines select li;
grdEmp.Rows.Add();
(grdEmp.Rows[count].Cells["Line"] as DataGridViewComboBoxCell).DataSource = line;
(grdEmp.Rows[count].Cells["Line"] as DataGridViewComboBoxCell).ValueMember = "L_id";
(grdEmp.Rows[count].Cells["Line"] as DataGridViewComboBoxCell).DisplayMember = "L_id";
But this didn't work. so how do I bind the data to ComboBox in my DataGridView

Try this :
DataGridViewComboBoxColumn combo = (DataGridViewComboBoxColumn)grdEmp.Columns["Line"];
combo.DataSource = line;
combo.ValueMember = "L_id";
combo.DisplayMember = "L_id"; // I also suspect this should be a text column

Editing the DataSource of a ComboBox

I have a ComboBox with its DataSource set to an instance of a DataTable. When rows are added to the DataTable, they show in the ComboBox without additional code, but when a row is deleted, the ComboBox remains unchanged. A short summary of my code:
ComboBox selector = new ComboBox();
DataTable tbl = new DataTable();
PopulateTable()
{
DataRow row1 = tbl.NewRow();
row1["field1"] = 1;
row1["field2"] = "Some Text";
tbl.Rows.Add(row1);
DataRow row2 = tbl.NewRow();
row2["field1"] = 2;
row2["field2"] = "More Text";
tbl.Rows.Add(row2);
}
PopulateSelector()
{
selector.DisplayMember = "field2";
selector.ValueMember = "field1";
selector.DataSource = tbl;
}
RemoveRow()
{
tbl.Rows[0].Delete();
}
At this point, the ComboBox appears to be correct, but clicking it resets it to its previous data. The DataTable remains correct, deleting the row causes no problem in that instance, I just can't make the ComboBox reflect the changes.

Try this:
PopulateSelector()
{
selector.DataSource = null;
selector.DisplayMember = "field2";
selector.ValueMember = "field1";
selector.DataSource = tbl;
}
RemoveRow()
{
tbl.Rows[0].Delete();
PopulateSelector()
}

You can use a bindingsource inbetween the datatable and the combobox and call ResetBindings

DataGridViewComboBoxColumn set the selectedindex

hi i runtime bind the data into datagridview combobox. But how do i make it to auto display the first item? i do not able find the selectedindex from DataGridViewComboBoxColumn.
DataGridViewComboBoxColumn cbStudentCourse = (DataGridViewComboBoxColumn)dgStudentCourse.Columns["studentCourseStatus"];
cbStudentCourse.DataSource = Enum.GetValues(typeof(CourseStudentStatus));
cbStudentCourse.DisplayIndex = 1;
-- Update ---
i saw someone doing this in solution 3
LInk
Are you sure i need such a long code to just have the first item selected??????

A DataGridViewComboBoxColumn has no SelectedIndex, and SelectedValue properties. However you can get the same behavior of SelectedValue by setting the Value property.
For instance on first index the value member has value 2 then you should set .Value = "2" to set the first index selected.
For example
myDataGridViewComboBoxColumn.Value = "20";
In your case
myDataGridViewComboBoxColumn.Value = CourseStudentStatus.EnumToBeSelected.ToString();
Here is more details about DataGridViewComboBoxColumn

the best way to set the value of a datagridViewComboBoxCell is:
DataTable dt = new DataTable();
dt.Columns.Add("Item");
dt.Columns.Add("Value");
dt.Rows.Add("Item1", "0");
dt.Rows.Add("Item1", "1");
dt.Rows.Add("Item1", "2");
dt.Rows.Add("Item1", "3");
DataGridViewComboBoxColumn cmb = new DataGridViewComboBoxColumn();
cmb.DefaultCellStyle.Font = new Font("Tahoma", 8, FontStyle.Bold);
cmb.DefaultCellStyle.ForeColor = Color.BlueViolet;
cmb.FlatStyle = FlatStyle.Flat;
cmb.Name = "ComboColumnSample";
cmb.HeaderText = "ComboColumnSample";
cmb.DisplayMember = "Item";
cmb.ValueMember = "Value";
DatagridView dvg=new DataGridView();
dvg.Columns.Add(cmb);
cmb.DataSource = dt;
for (int i = 0; i < dvg.Rows.Count; i++)
{
dvg.Rows[i].Cells["ComboColumnSample"].Value = (cmb.Items[0] as
DataRowView).Row[1].ToString();
}
It worked with me very well