while (true) //Show the dialog again and again, until Cancel is clicked or the entered credentials are correct.

        For example, it returns a bool 'credentialsEnteredCorrect':*/

      bool credentialsEnteredCorrect = false;

      if (credentialsEnteredCorrect) break; //Break the while-loop, if the entered credentials are correct.

static extern bool ArcTo(IntPtr hdc, int nLeftRect, int nTopRect,

   int nRightRect, int nBottomRect, int nXRadial1, int nYRadial1,

  ByVal nLeftRect As Integer, ByVal nTopRect As Integer, _

  ByVal nRightRect As Integer, ByVal nBottomRect As Integer, _

static extern bool ArcTo(IntPtr hdc, int nLeftRect, int nTopRect,

   int nRightRect, int nBottomRect, int nXRadial1, int nYRadial1,

  ByVal nLeftRect As Integer, ByVal nTopRect As Integer, _

  ByVal nRightRect As Integer, ByVal nBottomRect As Integer, _

The BitBlt function performs a bit-block transfer of the color data corresponding to a rectangle of pixels from the specified source device context into a destination device context.

///    rectangle of pixels from the specified source device context into

/// <param name="nXDest">The leftmost x-coordinate of the destination rectangle (in pixels).</param>

/// <param name="nYDest">The topmost y-coordinate of the destination rectangle (in pixels).</param>

/// <param name="nWidth">The width of the source and destination rectangles (in pixels).</param>

/// <param name="nHeight">The height of the source and the destination rectangles (in pixels).</param>

/// <param name="nXSrc">The leftmost x-coordinate of the source rectangle (in pixels).</param>

/// <param name="nYSrc">The topmost y-coordinate of the source rectangle (in pixels).</param>

'''    rectangle of pixels from the specified source device context into

''' <param name="nXDest">The leftmost x-coordinate of the destination rectangle (in pixels).</param>

''' <param name="nYDest">The topmost y-coordinate of the destination rectangle (in pixels).</param>

''' <param name="nWidth">The width of the source and destination rectangles (in pixels).</param>

''' <param name="nHeight">The height of the source and the destination rectangles (in pixels).</param>

''' <param name="nXSrc">The leftmost x-coordinate of the source rectangle (in pixels).</param>

''' <param name="nYSrc">The topmost y-coordinate of the source rectangle (in pixels).</param>

If a rotation or shear transformation is in effect in the source device context, BitBlt returns an error. If other transformations exist in the source device context (and a matching transformation is not in effect in the destination device context), the rectangle in the destination device context is stretched, compressed, or rotated, as necessary.

static extern bool Chord(IntPtr hdc, int nLeftRect, int nTopRect,

   int nRightRect, int nBottomRect, int nXRadial1, int nYRadial1,

Public Function Chord(ByVal hDc As IntPtr, ByVal nLeftRect As Integer, ByVal nTopRect As Integer,

               ByVal nRightRect As Integer, ByVal nBottomRect As Integer, ByVal nXRadial1 As Integer,

static extern bool ColorCorrectPalette(IntPtr hDC, IntPtr hPalette,

    public static extern IntPtr CreateEllipticRgn(int nLeftRect, int nTopRect,int nRightRect, int nBottomRect);

static extern IntPtr CreateBrushIndirect([In] ref LOGBRUSH lplb);

Private Shared Function CreateBrushIndirect( _

Private Declare Function CreateBrushIndirect Lib "gdi32"( _

static extern IntPtr CreateEllipticRgn(int nLeftRect, int nTopRect,

   int nRightRect, int nBottomRect);

static extern IntPtr CreateFontIndirect([In] ref LOGFONT lplf);

      public static extern IntPtr CreateFontIndirect(

static extern IntPtr CreateFontIndirect([In] ref LOGFONT lplf);

      public static extern IntPtr CreateFontIndirect(

drawingArea.FillRectangle(lGB, drawingArea.VisibleClipBounds)

static extern IntPtr CreateRectRgn(int nLeftRect, int nTopRect, int nRightRect, int nBottomRect);

Private Shared Function CreateRectRgn(ByVal nLeftRect As Integer, ByVal nTopRect As Integer, ByVal nRightRect As Integer, ByVal nBottomRect As Integer) As IntPtr

        static extern IntPtr CreateRectRgn(int nLeftRect, int nTopRect, int nRightRect,

            int nBottomRect);

                FillRgn(wDc, CreateRectRgn(0,0,mx,my), brush);

static extern IntPtr CreateRoundRectRgn(int x1, int y1, int x2, int y2,

        IntPtr _RegionHandle = CreateRoundRectRgn( 10, 10, 60, 60, 10, 10 );

        static extern IntPtr CreateRectRgn(int nLeftRect, int nTopRect, int nRightRect,

            int nBottomRect);

                FillRgn(wDc, CreateRectRgn(0,0,mx,my), brush);

POINT [] points = { new POINT(rect.Left, rect.Top), new POINT(rect.Right, rect.Bottom) };

static extern bool Ellipse(IntPtr hdc, int nLeftRect, int nTopRect,

   int nRightRect, int nBottomRect);

Private Shared Function Ellipse(hdc As IntPtr, nLeftRect As Integer, nTopRect As Integer, nRightRect As Integer, nBottomRect As Integer) As Boolean

    vGraphics.DrawRectangle(Pens.Blue, new Rectangle(0, 0, 300, 300));

    vGraphics.DrawRectangle(Pens.Blue, new Rectangle(50, 70, 300, 300));

   [In] ref RECT lprc, [MarshalAs(UnmanagedType.LPWStr)] string lpString,

See RECT.

        static extern IntPtr CreateRectRgn(int nLeftRect, int nTopRect, int nRightRect,

            int nBottomRect);

                FillRgn(wDc, CreateRectRgn(0,0,mx,my), brush);

static extern int GetClipBox(IntPtr hdc, out RECT lprc);

RECT

    /// Gets the full name directly out of specified True Type font file.

        // Get the correct name record

        NameRecord nameRecord = SeekCorrectNameRecord(br, records);

    /// Seeks the correct <see cref="NameRecord"/>.

    /// <returns>The <see cref="NameRecord"/> providing access to the correct full font name.</returns>

    private static NameRecord SeekCorrectNameRecord(BinaryReader br, int recordCount)

The only way I've been able to get ALL the kerning data is to parse the files directly; not easy to say the least.

  const int RDH_RECTANGLES = 1;

  unsafe RECT[] RectsFromRegion(IntPtr hRgn)

    RECT [] rects = null;

      if (header->iType == RDH_RECTANGLES)

    rects = new RECT[header->nCount];

    // The rectangle data follows the header, so we offset the specified

    // header size and start reading rectangles.

    int rectOffset = header->dwSize;

      // simple assignment from the buffer to our array of rectangles

      rects[i] = *((RECT *)((byte *)bytes+rectOffset+(Marshal.SizeOf(typeof(RECT)) *i)));

    // Return the rectangles

    return rects;

    GRADIENT_RECT[] pMesh,    // array of gradient rectangles, that each one keeps two indices in pVertex array, to determine its bounds

    uint dwNumMesh,       // number of gradient rectangles to draw

    GRADIENT_FILL dwMode);           // Use either GRADIENT_FILL.RECT_H or GRADIENT_FILL.RECT_V. Using the value GRADIENT_FILL.TRIANGLE is wrong in this overload!

    GRADIENT_FILL dwMode);           // Use only GRADIENT_FILL.TRIANGLE. Both values GRADIENT_FILL.RECT_H and GRADIENT_FILL.RECT_V are wrong in this overload!

GRADIENT_RECT

This method creates one entry each for rectangles and triangles. It's just a matter of convenience and error checking by the compiler.

static extern bool Pie(IntPtr hdc, int nLeftRect, int nTopRect, int nRightRect,

   int nBottomRect, int nXRadial1, int nYRadial1, int nXRadial2, int nYRadial2);

   Private Shared Function Pie(hdc As IntPtr, nLeftRect%, nTopRect%, nRightRect%, nBottomRect%, nXRadial1%, nYRadial1%, nXRadial2%, nYRadial2%) As Boolean

static extern bool PlayEnhMetaFile(IntPtr hdc, IntPtr hemf, ref RECT lpRect);

Changed lpRect from being an out parameter to a ref parameter. An out parameter will work in a debug build, but in a release build (with optimizations turned on) will not. Ref parameter works fine.

     static extern bool Rectangle(IntPtr hdc, int nLeftRect, int nTopRect, int nRightRect, int nBottomRect);

    Private Shared Function Rectangle(hdc As IntPtr, nLeftRect As Integer, nTopRect As Integer, nRightRect As Integer, nBottomRect As Integer) As Boolean

static extern bool RectInRegion(IntPtr hrgn, [In] ref RECT lprc);

static extern bool RoundRect(IntPtr hdc, int nLeftRect, int nTopRect,

   int nRightRect, int nBottomRect, int nWidth, int nHeight);

    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);

        DrawRoundRect(e.Graphics);

    public void DrawRoundRect(Graphics gr)

        RECT rect = new RECT(0, 0, this.Width, this.Height);

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

IntPtr hRegion = CreateRectRgn(left, top, right, bottom);

///   <para>SIMPLEREGION - Region consists of a single rectangle.</para>

///   <para>COMPLEXREGION - Region consists of more than one rectangle.</para>

static extern int SetArcDirection(IntPtr hdc, int ArcDirection);

There are two constants defining the direction.

    public static extern int Rectangle(IntPtr hDC, int nLeft, int nTop, int nRight, int nBottom);

double fAspectRatio = (double)(this.ClientRectangle.Bottom) / (double)(this.ClientRectangle.Right);

         this.ClientRectangle.Bottom,    // So that (0,0) is at the bottom left.

         this.ClientRectangle.Right,

         -this.ClientRectangle.Bottom, // Negative so that y gets positive as you go up.

// Draw a rectangle.

Rectangle(hDC, 10, 25, 990, (int)(990 * fAspectRatio));

static extern int DrawText(IntPtr hdc, string lpStr, int nCount,ref Rect lpRect, int wFormat);

private struct Rect

    public Rect(Rectangle r)

        e.Graphics.FillRectangle(backcolorBrush, e.Bounds);

        Rect bounds = new Rect(e.Bounds);

    e.DrawFocusRectangle();

[CharSet = CharSet.Auto] According to my experience this parameter should be used when using a LOGFONT structure and the CreateFontIndirect fuction, otherwise the selected font will not be displayed. All flags will be done (lfItalic, lfUnderline ...) but not the lfFaceName string.

ERROR_WINHTTP_INCORRECT_HANDLE_TYPE - The type of handle supplied is incorrect for this operation.

static extern int GdipAddPathRectanglesI(HandleRef path,

   HandleRef rects, int count);

Declare Function GdipAddPathRectanglesI Lib "gdiplus.dll" (TODO) As TODO

static extern int GdipAddPathRectangleI(HandleRef path, int x, int y,

Declare Function GdipAddPathRectangleI Lib "gdiplus.dll" (TODO) As TODO

static extern int GdipAddPathRectangles(HandleRef path,

   HandleRef rects, int count);

Declare Function GdipAddPathRectangles Lib "gdiplus.dll" (TODO) As TODO

   ref GPRECT layoutRect, HandleRef format);

   ref GPRECT dstRect, ref GPRECT srcRect, int unit, out int state);

static extern int GdipBitmapLockBits(HandleRef bitmap, ref GPRECT rect,

static extern int GdipCombineRegionRectI(HandleRef region,

   ref GPRECT gprect, CombineMode mode);

Declare Function GdipCombineRegionRectI Lib "gdiplus.dll" (TODO) As TODO

internal static extern int GdipMeasureString(HandleRef graphics, string textString, int length, HandleRef font, ref GPRECTF layoutRect, HandleRef stringFormat, [In, Out] ref GPRECTF boundingBox, out int codepointsFitted, out int linesFilled);

The signature is not correct. Instead use AviFileOpen together with CharSet = CharSet.Auto.

    '<MarshalAs(UnmanagedType.ByValArray, SizeConst:=4)> Public biCompression As Char()  ' for recup directly char (string) FOURCC

SQLInstallerError does not post error values for itself. SQLInstallerError returns SQL_NO_DATA when it is unable to retrieve any error information (in which case pfErrorCode is undefined). If SQLInstallerError cannot access error values for any reason that would normally return SQL_ERROR, SQLInstallerError returns SQL_ERROR but does not post any error values. If either the lpszErrorMsg argument is NULL or the cbErrorMsgMax is less than or equal to 0, this function returns SQL_ERROR. If the buffer for the error message is too short, SQLInstallerError returns SQL_SUCCESS_WITH_INFO and returns the correct pfErrorCode value for SQLInstallerError.

    void SaveLog(string eventLogName, string destinationDirectory)

        string exportedEventLogFileName = Path.Combine(destinationDirectory, eventLogName + ".evt");

As explained [here], memory for the returned unmanaged string must be freed by calling LocalFree. Therefore, you must define the string as an IntPtr in managed code and call LocalFree yourself. Otherwise, the marshaler would call CoTaskMemFree which is not correct in this case.

// Another C# Sample that converts a sid from a DirectoryEntry object

private string GetTextualSID(DirectoryEntry objGroup){

    ManagementObject Share = new ManagementObject("Win32_Directory='" + ToPath + "'");

        public static uint FILE_LIST_DIRECTORY = 0x1;

        public static uint FILE_ADD_SUBDIRECTORY = 0x4;

    string lpCurrentDirectory,

                           ByVal lpCurrentDirectory As String, _

     String             currentDirectory,

    Public Function CreateProcessWithLogonW(ByVal userName As String, ByVal domain As String, ByVal password As String, ByVal logonFlags As UInt32, ByVal applicationName As String, ByVal commandLine As String, ByVal creationFlags As UInt32, ByVal environment As UInt32, ByVal currentDirectory As String, ByRef startupInfo As StartupInfo, ByRef processInformation As ProcessInformation) As Boolean

    Public Function CreateProcessWithLogonW(ByVal userName As String, ByVal domain As String, ByVal password As String, ByVal logonFlags As UInt32, ByVal applicationName As String, ByVal commandLine As String, ByVal creationFlags As UInt32, ByVal environment As UInt32, ByVal currentDirectory As String, ByRef startupInfo As StartupInfo, ByRef processInformation As ProcessInformation) As Boolean

    Dim currentDirectory As String = System.IO.Directory.GetCurrentDirectory()

        currentDirectory, startupInfo, processInfo)

            String currentDirectory,

            String currentDirectory = System.IO.Directory.GetCurrentDirectory();

                    currentDirectory,

I changed the C# version from using "out uint lpdwTagId" to "string lpdwTagId". Without that change, the C# call to CreateService always returned an incorrect parameter error.

For Directories

System.Security.AccessControl.DirectorySecurity

Local or remote files or directories on an NTFS file system

Directory service objects