[c#] How do you resize a form to fit its content automatically?

I am trying to implement the following behaviour:

On a form there is a tabcontrol. On that tabcontrol there is a treeview. To prevent scrollbars appearing, I would like the form to change its size according to the contents of the treeview when displayed for the first time.

If the treeview has too many nodes to be displayed on the default size of the form, the form should change it's size so that there is no vertical scrollbar on the treeview (up to a maximum size allowed by the size of the screen).

What I need to know is, if it is possible to achieve this behaviour through the properties of the controls. I'm sure this can be achieved by calculating and settings the sizes of the elements programmatically, but I would like to know if there is a way to achieve this by settings like AutoSizeMode etc.

[UPDATE]

It's the first dialog a user of my application sees: It's a dialog to select the database to work with. It's a list of databases, with a tabcontrol, buttens etc. If the list is too long, scrollbars appear and a colleague of mine wants them to disappear.

From MSDN:

To maximize productivity, the Windows Forms Designer shadows the AutoSize property for the Form class. At design time, the form behaves as though the AutoSize property is set to false, regardless of its actual setting. At runtime, no special accommodation is made, and the AutoSize property is applied as specified by the property setting.

This technique solved my problem:

In parent form:

frmEmployee frm = new frmEmployee();
frm.MdiParent = this;
frm.Dock = DockStyle.Fill;
frm.Show();

In the child form (Load event):

this.WindowState = FormWindowState.Maximized;

I User this Code in my project, Useful for me.

    private void Form1_Resize(object sender, EventArgs e)
    {
        int w = MainPanel.Width; // you can use form.width when you don't use panels

        w = (w - 120)/4; // 120 because set 15px for each side of panels
                         // and put panels in FlowLayoutPanel
                         // 4 because i have 4 panel boxes
        panel1.Width = w;
        panel2.Width = w;
        panel3.Width = w;
        panel4.Width = w;
    }

You could calculate the required height of the TreeView, by figuring out the height of a node, multiplying it by the number of nodes, then setting the form's MinimumSize property accordingly.

// assuming the treeview is populated!
nodeHeight = treeview1.Nodes[0].Bounds.Height;

this.MaximumSize = new Size(someMaximumWidth, someMaximumHeight);

int requiredFormHeight = (treeView1.GetNodeCount(true) * nodeHeight);

this.MinimumSize = new Size(this.Width, requiredFormHeight);

NB. This assumes though that the treeview1 is the only control on the form. When setting the requiredFormHeight variable you'll need to allow for other controls and height requirements surrounding the treeview, such as the tabcontrol you mentioned.

(I would however agree with @jgauffin and assess the rationale behind the requirement to resize a form everytime it loads without the user's consent - maybe let the user position and size the form and remember that instead??)

I used this code and it works just fine

const int margin = 5;
        Rectangle rect = new Rectangle(
            Screen.PrimaryScreen.WorkingArea.X + margin,
            Screen.PrimaryScreen.WorkingArea.Y + margin,
            Screen.PrimaryScreen.WorkingArea.Width - 2 * margin,
            Screen.PrimaryScreen.WorkingArea.Height - 2 * (margin - 7));
        this.Bounds = rect;

If you trying to fit the content according to the forms than the following will help. It helps me while I was trying to fit the content on the form to fit when ever the forms were resized.

this.contents.Size = new Size(this.ClientRectangle.Width, this.ClientRectangle.Height);

This might be useful. It resizes a new form to a user control, and then anchors the user control to the new form:

Form f = new Form();
MyUserControl muc = new MyUserControl();
f.ClientSize = muc.Size;
f.Controls.Add(muc);
muc.Anchor = AnchorStyles.Top | AnchorStyles.Bottom | AnchorStyles.Left | AnchorStyles.Right;
f.ShowDialog();

Use the AutoSize and AutoSizeMode properties.

http://msdn.microsoft.com/en-us/library/system.windows.forms.form.autosize.aspx

An example:

private void Form1_Load(object sender, EventArgs e)
{
    // no smaller than design time size
    this.MinimumSize = new System.Drawing.Size(this.Width, this.Height);

    // no larger than screen size
    this.MaximumSize = new System.Drawing.Size(Screen.PrimaryScreen.Bounds.Width, Screen.PrimaryScreen.Bounds.Height, (int)System.Windows.SystemParameters.PrimaryScreenHeight);

    this.AutoSize = true;
    this.AutoSizeMode = AutoSizeMode.GrowAndShrink;

    // rest of your code here...
}

By using the various sizing properties (Dock, Anchor) or container controls (Panel, TableLayoutPanel, FlowLayoutPanel, etc.) you can only dictate the size from the outer control down to the inner controls. But there is nothing (working) within the .Net framework that allows to dictate the size of a container through the size of the child control. I also missed this a few times and tried the AutoSize property, but it never worked.

So all you can do is trying to get this stuff done manually, sorry.