Desktop Functions:

   Smart Device Functions:

Show Recent Changes
Subscribe (RSS)
Misc. Pages
Helpful Tools
Suggested Reading
Website TODO List
Support Forum
Download Visual Studio Add-In

Terms of Use
Privacy Policy
RoundRect (gdi32)

C# Signature:

static extern bool RoundRect(IntPtr hdc, int nLeftRect, int nTopRect,
   int nRightRect, int nBottomRect, int nWidth, int nHeight);

User-Defined Types:




Tips & Tricks:

Please add some!

Sample Code:

public class GDI32
    #region GDI32 Functions
    public static extern bool RoundRect(RECT lpRect, Point point);

    public static extern bool RoundRect(IntPtr hdc, int nLeftRect, int nTopRect,
    int nRightRect, int nBottomRect, int nWidth, int nHeight);

    public static extern IntPtr CreateSolidBrush(uint crColor);

    public static extern IntPtr CreatePen(int fnPenStyle, int nWidth, uint crColor);

    public static extern IntPtr SelectObject(IntPtr hdc, IntPtr hgdiobj);

    public static extern bool DeleteObject(IntPtr hObject);

    public static int RGB(Color color)
        return color.ToArgb() & 0xffffff;


public class RoundControl : System.Windows.Forms.Control
    protected override void OnPaint(PaintEventArgs e)

    public void DrawRoundRect(Graphics gr)
        RECT rect = new RECT(0, 0, this.Width, this.Height);
        IntPtr hDC = gr.GetHdc();
        IntPtr thePen = GDI32.CreatePen(0, 1, (uint)GDI32.RGB(Color.White));
        IntPtr theBrush = GDI32.CreateSolidBrush((uint)GDI32.RGB(Color.White));
        IntPtr oldPen = GDI32.SelectObject(hDC, thePen);
        IntPtr oldBrush = GDI32.SelectObject(hDC, theBrush);        

        GDI32.RoundRect(hDC, 0, 0, this.Width, this.Height, 20, 20);

        GDI32.SelectObject(hDC, oldPen);
        GDI32.SelectObject(hDC, oldBrush);            


Alternative Managed API:

Do you know one? Please contribute it!

RoundRect on MSDN

Please edit this page!

Do you have...

  • helpful tips or sample code to share for using this API in managed code?
  • corrections to the existing content?
  • variations of the signature you want to share?
  • additional languages you want to include?

Select "Edit This Page" on the right hand toolbar and edit it! Or add new pages containing supporting types needed for this API (structures, delegates, and more).

Access directly from VS:
Terms of Use
Edit This Page
Find References
Show Printable Version