C# Setting Form Child of another form

[Studlyami]

I have form1 and form2. I want form2 to be a child of form1 so that when i set its location it will be drawn in relation to its parent.
EX:

 Form2Object.Location = new point (0,0)

would put form2 at the top left corner of form one.

I set the MDI property to true for form one. My Created my form2 like so:

Form2 Form2Object = new Form2();
Form2Object.Parent = this; //causes error see below
Form2Object.Location = new point (0,0); 
 

The error i get is
An unhandled exception of type 'System.Argumen tException' occurred in System.Windows. Forms.dll

Additional information: Top-level control cannot be added to a control.

[Shashi Sadasivan]

You could have a form be a child of another if the parent is an MDi Container.
which means that the form will be placed inside the MDI container.
How about passing the form1 object itself to form2 in the constructor and then computing the location for it to be placed in?

[Studlyami]

I have set the parent form MDI option. Within the parent form (form1) constructor is where i have

      Form2 Form2Object = new Form2();
      Form2Object.Parent = this; //causes error see below
      Form2Object.Location = new point (0,0);
 

Within the form1 constructor i could get the rect and then do screen to client and have the window appear where i want it to, but then i would have to do this everytime form1 moves.

[Shashi Sadasivan]

well....
The issue is because of form1 not exactly being able to be a parent for form2.
Could you please tell what do you mean by MDI Option?
as in the proprty that you set for that. is that isMDIContainer?

Moreover since form2's position is being set from form1 itself, you can disregards setting form2's parent (so delete the line where you set form2.Parent = this;)

It should be fine then.

cheers

[Studlyami]

When i say i set the MDI option that is the option under the properties of the form (IsMDIContainer ). Right now when i do the Form2.Location = new Point (0,0) it gets drawn at the top left of my monitor not the top left of Form1.

[Shashi Sadasivan]

When i say i set the MDI option that is the option under the properties of the form (IsMDIContainer ). Right now when i do the Form2.Location = new Point (0,0) it gets drawn at the top left of my monitor not the top left of Form1.

0,0 represents the co-ordintaes in the screen.
You might have to use the PointToClient Method

Form2.Location = this.PointToClient(0,0);

hoping that this form is opened from form1 and this refers to the Form1 object
Hope this works

[Plater]

Suppose you have this:

Form1 frm1 = new Form1();
Form2 frm2 = new Form2();
frm1.IsMDIContainer=true;
frm2.Parent=frm1;
frm2.Location=new Point(0,0);
frm1.Show();
 

That *should* work.


Although I generally prefer to do it:

Form1 frm1 = new Form1();
Form2 frm2 = new Form2();
frm2.Location=new Point(0,0);
frm1.Controls.Add(frm2);
frm1.Show();
 

[Studlyami]

Although I generally prefer to do it:

Form1 frm1 = new Form1();
Form2 frm2 = new Form2();
frm2.Location=new Point(0,0);
frm1.Controls.Add(frm2);
frm1.Show();
 

At the frm1.Controls.A dd(frm2)
i get the same error
"An unhandled exception of type 'System.Argumen tException' occurred in System.Windows. Forms.dll

Additional information: Top-level control cannot be added to a control."

I was able to get it to work. My problem was the

frm1.Parent = this   //This line has to be 
frm1.MdiParent = this;
 

What advantage is there between setting the frm2 parent vs the frm1.Controls.A dd(frm2)?

[Plater]

What advantage is there between setting the frm2 parent vs the frm1.Controls.A dd(frm2)?

Not sure, other then that you can treat the form like any other control. You can tell the form not to draw it's status bar and will be just like you added a panel to your form.