Datagridview - How to update programatically a hidden column in C# winforms.

I don't understand how e.RowIndex can be -1 when the CellValueChanged event fires but you definitely need e.ColumnIndex to be 1 because otherwise the third column will still be changed automatically if you change the ID column (ColumnIndex = 0) which is not what you want.

So, I'd use:

Hi vulpes,

When tried you proposal, I got e.RowIndex = -1

Then used: if (e.RowIndex > -1) instead of (e.ColumnIndex == 1) and it worked

I need your help for this please

CellClick is the event you need to look at

Ehtesham

I Think we are near of the solution.

All what is needed here is just to update one datagrid cell when another just has been changed. Do you know the right event to use?

Many thanks

Samio, I have just used datatable to bind datagridview and to give an example. You wanted to change datagridview cell values right you just have to look at button1_Click method, The changes are only for gridview not for database if you want to make changes to database depending gridview you need to use dataadapter and commandbuilder for above case

I am using Entity Framework, I do not know if it is possible mix it with datasets since you use in your code dataTables

also it is not good practice to select the whole row each time you need to update the hidden column, I think it should be better to update it once the current cell value changed.

Consider the below working code

 public partial class Form1 : Form
  {

  public Form1()
  {
  InitializeComponent();
  DataTable dt = new DataTable();
  dt.Columns.Add("Col1", typeof(string));
  dt.Columns.Add("Col2", typeof(string));
  dt.Columns.Add("Col3", typeof(string));
  DataRow dr = dt.NewRow();
  dr["Col1"] = "ValRow1Col1";
  dr["Col2"] = "ValRow1Col2";
  dr["Col3"] = "ValRow1Col2";
  dt.Rows.Add(dr);
  dr = dt.NewRow();
  dr["Col1"] = "ValRow2Col1";
  dr["Col2"] = "ValRow2Col2";
  dr["Col3"] = "ValRow2Col2";
  dt.Rows.Add(dr);
  dataGridView1.DataSource = dt;
  this.dataGridView1.Columns["Col3"].Visible = false;
  }

  private void button1_Click(object sender, EventArgs e)
  {
  this.dataGridView1.CurrentRow.Cells["Col3"].Value = "Changed";
  MessageBox.Show(this.dataGridView1.CurrentRow.Cells["Col3"].Value.ToString());
  }
  }

Make sure you have selected row from datagridview

Yes Ehtesham , that's right:

dataGridView1.CurrentRow.Cells[2].Value = DateTime.Now

instead of

dataGridView1.CurrentRow.Cells(2).Value = DateTime.Now

solved the compile error.

Please have you an idea on how to change the hidden column value of the current row by code ? I mean which event of datagridview should be used to allow saving values in several rows before persisting data to the database.

Change dataGridView1.CurrentRow.Cells(2).Value = DateTime.Now to dataGridView1.CurrentRow.Cells[2].Value = DateTime.Now

I assume you are getting compile time error as you are using c# not vb.net

"dataGridView1.CurrentRow.Cells(2).Value = dateTime.Now;" till now is placed in SaveButton click event. It is not its right place since we can change multiple rows in the datagridview before persisting changes to database.

Could not use dt.GetChanges, my dataGridView1.datasource is bindingSource1 and bindingSource1.DataSource = nw.Orders

Where you have placed this code ? "dataGridView1.CurrentRow.Cells(2).Value = dateTime.Now;"
To fetch the modified records,
DataTable changedDatatable = dt.GetChanges();

Once the you got the modified records, then you can call MyEntities.SaveChanges();

Please let me know, your thoughts on this.