How to select a part of the text of a DataGridView cell in c# with Windows Forms?

Question

I'm working on a C# project with Windows Forms and I'm having trouble with a problem that's taking up a lot of my time. The problem is that I want to be able to select only part of the text in a cell that is supposed to be readonly, in order to perform actions on it. For a small example, in Microsoft Access, it's possible to select part of a text without modifying it: example microsoft access I tried a lot of things such as to catch the event CellBeginEdit, etc..., with no results.

Thank you for your help !

Answer 1

allowing text selection in a readonly cell for the purpose of copying or performing other actions on the selected text is not directly supported as a built-in feature. But, you can achieve this functionality through a workaround.

You can use a TextBox as an overlay and allow text selection.

private TextBox readOnlyTextBoxOverlay;

public YourFormConstructor()
{
    InitializeComponent();
    InitializeReadOnlyTextBoxOverlay();
}

private void InitializeReadOnlyTextBoxOverlay()
{
    readOnlyTextBoxOverlay = new TextBox
    {
        ReadOnly = true,
        Multiline = true,
        Visible = false,
        BorderStyle = BorderStyle.None
    };
    this.Controls.Add(readOnlyTextBoxOverlay);
    readOnlyTextBoxOverlay.BringToFront();
    readOnlyTextBoxOverlay.Leave += (s, e) => readOnlyTextBoxOverlay.Visible = false;
}

private void dataGridView1_CellClick(object sender, DataGridViewCellEventArgs e)
{
    if (e.RowIndex >= 0 && e.ColumnIndex >= 0) // Check if the click is on a valid cell
    {
        Rectangle cellRect = dataGridView1.GetCellDisplayRectangle(e.ColumnIndex, e.RowIndex, false);

        readOnlyTextBoxOverlay.Location = cellRect.Location;
        readOnlyTextBoxOverlay.Size = cellRect.Size;
        readOnlyTextBoxOverlay.Text = dataGridView1[e.ColumnIndex, e.RowIndex].Value?.ToString();
        readOnlyTextBoxOverlay.Visible = true;
        readOnlyTextBoxOverlay.Focus();
        readOnlyTextBoxOverlay.SelectAll();
    }
}

private void dataGridView1_CellLeave(object sender, DataGridViewCellEventArgs e)
{
    readOnlyTextBoxOverlay.Visible = false;
}

The textBox is initialy hidden because it will only be visible once you clicked the cell you want to "edit" select something for copying or something