CODEWITHSUNDEEP
c#formswinformssize
TaW
TaW

Reputation: 54433

Sizing Form with Mouse works, with code doesn't go below 178x47

This 

public Form1()
{
    InitializeComponent();
    Size = new System.Drawing.Size(8, 8);
    Console.WriteLine("Size: " + Size);
}

produces this as the output:

Size: {Width=178, Height=47}

Now I guess that is because some space is needed for the title bar and its controls and the form border.

But after removing all these things the result still is the same, even though I can reduce the Form to anything smaller when using the Mouse!

Here is the tiny program I tried to improve with a keyboard interface:

public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();
        MinimumSize = new System.Drawing.Size(6, 6);
    }

    public const int WM_NCLBUTTONDOWN = 0xA1;
    public const int HT_CAPTION = 0x2;

    [DllImportAttribute("user32.dll")]
    public static extern int SendMessage(IntPtr hWnd, int Msg, int wParam, int lParam);
    [DllImportAttribute("user32.dll")]
    public static extern bool ReleaseCapture();

    private void Form1_MouseDown(object sender, System.Windows.Forms.MouseEventArgs e)
    {
        if (e.Button == MouseButtons.Left)
        {
            ReleaseCapture();
            SendMessage(Handle, WM_NCLBUTTONDOWN, HT_CAPTION, 0);
        }
    } 

    private void Form1_Resize(object sender, EventArgs e)
    {
        label1.Text = Width + " x " + Height + " px";
    }

    private void Form1_KeyDown(object sender, KeyEventArgs e)
    {
        if (e.KeyCode == Keys.Right && e.Shift) Width++;
        else if (e.KeyCode == Keys.Down && e.Shift) Height++;
        else if (e.KeyCode == Keys.Left && e.Shift) Width--;
        else if (e.KeyCode == Keys.Up && e.Shift) Height--;
        else if (e.KeyCode == Keys.Right) Left++;
        else if (e.KeyCode == Keys.Down) Top++;
        else if (e.KeyCode == Keys.Left) Left--;
        else if (e.KeyCode == Keys.Up) Top--;
    }
}

The Form has one Label and nothing else:

        // 
        // Form1
        // 
        this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.None;
        this.ClientSize = new System.Drawing.Size(282, 253);
        this.ControlBox = false;
        this.Controls.Add(this.label1);
        this.KeyPreview = true;
        this.MaximizeBox = false;
        this.MinimizeBox = false;
        this.MinimumSize = new System.Drawing.Size(2, 2);
        this.Name = "Form1";
        this.ShowIcon = false;
        this.KeyDown += new System.Windows.Forms.KeyEventHandler(this.Form1_KeyDown);
        this.MouseDown += new System.Windows.Forms.MouseEventHandler(this.Form1_MouseDown);
        this.Resize += new System.EventHandler(this.Form1_Resize);
        this.ResumeLayout(false);
        this.PerformLayout();

I wonder why the mouse lets me shrink it but the code doesn't? Are there some style bits I need to set?

Upvotes: 2

Views: 107

Answers (2)

Sandwich
Sandwich

Reputation: 356

I think this is because of the forms border style, looks like changing it to None allows the form to shrink smaller. Also moving the re-sizing code to the form's load event helps.

Edit: Setting FormBorderStyle to SizeableToolWindow seems like the best fit, allows the form to be pretty small and still resized using the mouse.

Upvotes: 1

iceberg
iceberg

Reputation: 596

Overriding CreateParams for Form and setting WS_POPUP style allows to set any size for Form in case FormBorderStyle is set to FormBorderStyle.None. Otherwise, size of the border and title will be added.

uint WS_POPUP = 0x80000000;

protected override CreateParams CreateParams
{
    get
    {
        CreateParams createParams = base.CreateParams;
        createParams.Style |= unchecked((int)WS_POPUP);
        return createParams;
    }
}

Upvotes: 0

Related Questions