How to disable the MDIparent form when a child form is active

[jeffrey4u]

Hi there
Am a new student in C# and am using Microsoft Visual C# 2013.
My aim is to
i. open a child form inside its MDIparent form
ii. disable the MDIparent form when the child form is active/opened

it was easier in VB.net with

frmStuDetails.ShowDialog()

I have tried

1.

MyChildForm childForm = new MyChildForm();
childForm.ShowDialog(this);

Result....but the problem is that the child form doesn't open within the MDIparent form/container

2.
under MDIparent call button

frmViewStuList childForm = new frmViewStuList(this);
childForm.Owner = this;
childForm.Show();

under child from Activated

 if (this.Owner != null)
  {
    this.Owner.Enabled = false;
  }

under child form Deactivate

 if (this.Owner != null)
 {
   this.Owner.Enabled = true;
 }

Result.....it makes the child form active but freezes the MDIparent when the child form closes

3.

ChildForm child = new ChildForm();
child.Owner = this;
child.Show();

// In ChildForm_Load:
private void ChildForm_Load(object sender, EventArgs e) 
{
  this.Owner.Enabled = false;
}

private void ChildForm_Closed(object sender, EventArgs e) 
{
  this.Owner.Enabled = true;
} 

Result ....It seems to be the best option but the child form doesn't open within the MDIparent

Please help if you have any other idea
Thanks

[tinstaafl]

One option would be to just disable the controls on the MDIParent.

First set the MDIParent property insted of the Owner property.

Second add a static method to enable/disable the controls:

    public static void EnableControls(Form thisForm, bool enable = true)
    {
        if (thisForm.IsMdiContainer)
        {
            foreach (Control c in thisForm.Controls)
            {
                //The MDIChild is in the MdiClient.  This way it stays active.               
                if(c.GetType() != typeof(MdiClient))
                {
                    c.Enabled = enable;
                }
            }
        }
    }

In the MDIParent when you show the child also call this new method:

    MdiChildren[0].Show();
    EnableControls(this, false);

In the MDIChild FormClosed event handler re-enable the MDIParent's controls:

//Class of the MDIContainer
Form1.EnableControls(MdiParent);

[jeffrey4u]

Guess the static method will be addedto both the child and the MDI parent form.
Is working as expected.
Thanks alot for your answer

[tinstaafl]

Because it's static it just needs to be public in one class. Access it through the class name.

If this works for you please remember to mark this solved. Thanks

[jeffrey4u]

Good job
thanks