Resizing a Form with Ratio

[Scott Gross]

What is the proper way to proportionally resize a form?

Currently I just have:

private void Form1_Resize(object sender, EventArgs e)
{
    this.Height = this.Width;
}

This correctly resizes the height when it's horizontally resized, but it flickers between the initial size and the "dragging" size.

Any idea on how to fix this?

I need this to work vertically as well.  Ideally I'd like to have the ratio calculated from the initial size.

Hope someone can help.

Thank you

[Boyko Markov]

Hello,

You can try the following solution for resizing a form proportionally.
Place the following code in your form:

protected override void WndProc(ref Message m)
{
    const int WM_EXITSIZEMOVE = 0x232;
    const int WM_SYSCOMMAND = 0x112;

    switch (m.Msg)
    {
        case WM_EXITSIZEMOVE: // Form is moved or resized

            base.WndProc(ref m);
            FormResized();
            break;

        case WM_SYSCOMMAND: // System command (maximize, minimize, restore, etc.)

            base.WndProc(ref m);

            const int SC_MAXIMIZE = 0xF030;
            const int SC_MINIMIZE = 0xF020;
            const int SC_RESTORE = 0xF120;

            switch (m.WParam.ToInt32())
            {
                case SC_MAXIMIZE: // Form is maximized by control
                case SC_MAXIMIZE + 2: // Form is maximized by title bar
                    FormResized();
                    break;

                case SC_MINIMIZE: // Form is minimized by control
                    FormResized();
                    break;

                case SC_RESTORE: // Form is restored by control
                case SC_RESTORE + 2: // Form is restored by title bar
                    FormResized();
                    break;

                default:
                    break;
            }
            break;

        default:

            base.WndProc(ref m);
            break;
    }
}

private int lastWidth;
private int lastHeight;

void FormResized()
{

    if (this.Width != this.lastWidth)
    {
        this.Height = this.Width;
    }
    else
        if (this.Height != this.lastHeight)
        {
            this.Width = this.Height;
        }


    this.lastWidth = this.Width;
    this.lastHeight = this.Height;

}

The actual resizing is executed in the FormResize method.
I hope this works for you.

All the best,
Ray
the telerik team

Instantly find answers to your questions at the new Telerik Support Center

[MattLynch]

You can also try this:

this.SuspendLayout();

// perform any special resizing...

this.ResumeLayout();

[Scott Gross]

this is close. I need it to resize dynamically while I'm dragging though.  Is there a way to make it dynamic?

[MattLynch]

Your requirements are specialized, so your code needs to be specialized too. 

Try this: Take Telerik's sample, and modify the FormResized method.

void FormResized()

{

this.SuspendLayout();

if (this.Width != this.lastWidth)

{

this.Height = this.Width;

}

else

if (this.Height != this.lastHeight)

{

this.Width = this.Height;

}

this.lastWidth = this.Width;

this.lastHeight = this.Height;

this.ResumeLayout();

}

Have you thought about what happens on a wide screen monitor?  In a maximized state, your controls will not be proportional, because the screen size is not a square.  To maintain the correct proportions, you would need to disable maximizing (2 cases - via the title bar + via the control box).

Have fun...