Check All Checkbox items on DataGridView

Question

Here's the scenario.

I have checkbox(Name:"Check All" ID:chkItems) and datagridview. And when I click on this checkbox, all checkboxes on the datagridview will also be checked.

I've also added the checkbox column on the grid.

DataGridViewCheckBoxColumn CheckboxColumn = new DataGridViewCheckBoxColumn();
CheckBox chk = new CheckBox();
CheckboxColumn.Width = 20;
GridView1.Columns.Add(CheckboxColumn);

Here is the code behind of the checkbox. There is a problem on the row.Cell

private void chkItems_CheckedChanged(object sender, EventArgs e)
{
    foreach (DataGridViewRow row in GridView1.Rows)
    {
        DataGridViewCheckBoxCell chk = e.row.Cells(0);
        if (chk.Selected == false)
        {
            row.Cells(0).Value = true;
        }
    }
}   

Solution 1

DataGridViewCheckBoxCell chk = (DataGridViewCheckBoxCell) row.Cells[0];

instead of

DataGridViewCheckBoxCell chk = e.row.Cell(0);

*EDIT:*I think you really want to do this:

foreach (DataGridViewRow row in dataGridView1.Rows)
{
       DataGridViewCheckBoxCell chk = (DataGridViewCheckBoxCell) row.Cells[0];
       chk.Value = !(chk.Value == null ? false : (bool) chk.Value); //because chk.Value is initialy null
}

Solution 2

    private void setCheckBoxInDataGrid(DataGridView dgv, int pos, bool isChecked)
    {
        for (int i = 0; i < dgv.RowCount; i++)
        {
            dgv.Rows[i].DataGridView[pos, i].Value = isChecked;
        }
    }

This is how I did it

Solution 3

Try this one

foreach (DataGridViewRow row in this.dataGridView1.Rows)
{
      row.Cells[0].Value = row.Cells[0].Value == false ? true : false;

}

Comments

[user1647667]

when i tried this one, DataGridViewCheckBoxCell chk = row.Cells[0]; there is still error on row.cells[0];

[Nikola Davidovic]

check the edit, you need to cast the Cell to DataGridViewCheckBoxCell

[user1647667]

there's error on the checkbox column that i created // Unable to cast object of type 'System.Windows.Forms.DataGridViewImageCell' to type 'System.Windows.Forms.DataGridViewCheckBoxCell'.

[Nikola Davidovic]

What is the index of the DataGridViewCheckBoxColumn in your datagridview?

[user1647667]

i've added this column DataGridViewCheckBoxColumn CheckboxColumn = new DataGridView CheckBoxColumn(); CheckBox chk = new CheckBox(); CheckboxColumn.Width = 20; GridView1.Columns.Add(CheckboxColumn);

[user1647667]

Thanks! I'm done with it. but there's a problem. there's no chk.Checked it chk.Selected. that's why it's only selecting the item. how can i check the checkbox?

[Nikola Davidovic]

I see it from the code you posted but there is also some other column in you dataGridView that is making problems

[Nikola Davidovic]

I've posted that edit already, load it. You should access chk.Value

[smulholland2]

I used this answer but another one was a little more helpful in case you need to select all checkboxes after some user input that might set a checkbox cell into edit mode. In that case, this answer leaves the edit mode cells as they are. Replace chk.Value !=... in the answer about with this:chk.Value = !(chk.EditedFormattedValue.ToString() == "false" ? false : (bool)chk.EditedFormattedValue); and you should be in good shape.

[smulholland2]

It also helps to set the dgv.DefaultCell = null;