How can I better control behavior on multiple controls at once?

Question

So I have a form with some tab objects, group objects and possible a table layout pannel inside of a group object.

Based on data locks the form will disable almost all of its content so I need to mark things as read only so the users can still see the data but not change it...

Here is the code I have to dive through collections and mark objects as read only...

    private void lockForm()
    {
        btnLockData.BackColor = Color.LightBlue;
        btnLockData.Text = "Data locked!  Click to unlock...";

        foreach (Control formObject in this.Controls)
        {
            if (formObject is TabControl)
            {
                foreach (Control tabControl in (formObject.Controls))
                {
                    foreach (Control tabPageObject in (tabControl.Controls))
                    {
                        if (tabPageObject is TextBox)
                            ((TextBox)tabPageObject).ReadOnly = true;

                        if (tabPageObject is DataGridView)
                            ((DataGridView)tabPageObject).ReadOnly = true;


                        if (tabPageObject is GroupBox)
                        {
                            foreach (Control groupBoxObject in tabPageObject.Controls)
                            {
                                if (groupBoxObject is TextBox)
                                    ((TextBox)groupBoxObject).ReadOnly = true;

                                if (groupBoxObject is DataGridView)
                                    ((DataGridView)groupBoxObject).ReadOnly = true;

                                if (groupBoxObject is TableLayoutPanel)
                                {
                                    foreach (Control layoutObject in groupBoxObject.Controls)
                                    {
                                        if (layoutObject is TextBox)
                                            ((TextBox)layoutObject).ReadOnly = true;

                                        if (layoutObject is DataGridView)
                                            ((DataGridView)layoutObject).ReadOnly = true;                                            
                                    }
                                }
                            }
                        }
                    }
                }
            }
        }

        dgvResources.ReadOnly = false;
        dgvDirectLabor.ReadOnly = false;
    }

Is there a better way to control this behavior?

Answer 1

For more granular control of which controls to set Readonly try:

   this.Controls.Cast<Control>()
        .Where(ctl => ctl is TextBox).Cast<TextBox>().ToList()
        .ForEach(e => e.ReadOnly = true);

    this.Controls.Cast<Control>()
        .Where(ctl => ctl is DataGridView).Cast<DataGridView>().ToList()
        .ForEach(e => e.ReadOnly = true);

Answer 2

This should do the trick for WinForms:

var controls = from controls in this.Controls.OfType<Control>()
              select controls;
foreach(c in controls) { c.Enabled = false; }