UnsafeNativeMethods.cs source code in C# .NET

Source code for the .NET framework in C#

                        
Code:

                         / DotNET / DotNET / 8.0 / untmp / whidbey / REDBITS / ndp / fx / src / CommonUI / System / Drawing / UnsafeNativeMethods.cs / 1 / UnsafeNativeMethods.cs
                        

                        
                            //------------------------------------------------------------------------------ 
// 
//     Copyright (c) Microsoft Corporation.  All rights reserved.
// 
//----------------------------------------------------------------------------- 

[assembly: System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Performance", "CA1811:AvoidUncalledPrivateCode", Scope="member", Target="System.Drawing.UnsafeNativeMethods..ctor()")] 
 
namespace System.Drawing {
    using System.Runtime.InteropServices; 
    using System;
    using System.Security.Permissions;
    using System.Collections;
    using System.IO; 
    using System.Text;
    using System.Diagnostics.CodeAnalysis; 
 
    [
    System.Security.SuppressUnmanagedCodeSecurityAttribute() 
    ]
    internal class UnsafeNativeMethods {

        [SuppressMessage("Microsoft.Security", "CA2118:ReviewSuppressUnmanagedCodeSecurityUsage")] 
        [DllImport(ExternDll.Kernel32, SetLastError=true, ExactSpelling=true, EntryPoint="RtlMoveMemory", CharSet=System.Runtime.InteropServices.CharSet.Auto)]
        public static extern void CopyMemory(HandleRef destData, HandleRef srcData, int size); 
 
        [DllImport(ExternDll.User32, SetLastError=true, ExactSpelling=true, EntryPoint="GetDC", CharSet=System.Runtime.InteropServices.CharSet.Auto)]
        private static extern IntPtr IntGetDC(HandleRef hWnd); 
        public static IntPtr GetDC(HandleRef hWnd) {
            return System.Internal.HandleCollector.Add(IntGetDC(hWnd), SafeNativeMethods.CommonHandles.HDC);
        }
 
        [DllImport(ExternDll.Gdi32, SetLastError=true, ExactSpelling=true, EntryPoint="DeleteDC", CharSet=CharSet.Auto)]
        private static extern bool IntDeleteDC(HandleRef hDC); 
        public static bool DeleteDC(HandleRef hDC) { 
            System.Internal.HandleCollector.Remove((IntPtr)hDC, SafeNativeMethods.CommonHandles.GDI);
            return IntDeleteDC(hDC); 
        }

        [DllImport(ExternDll.User32, SetLastError=true, ExactSpelling=true, EntryPoint="ReleaseDC", CharSet=System.Runtime.InteropServices.CharSet.Auto)]
        private static extern int IntReleaseDC(HandleRef hWnd, HandleRef hDC); 
        public static int ReleaseDC(HandleRef hWnd, HandleRef hDC) {
            System.Internal.HandleCollector.Remove((IntPtr)hDC, SafeNativeMethods.CommonHandles.HDC); 
            return IntReleaseDC(hWnd, hDC); 
        }
 
#if false
        // Not currently used.
        [DllImport(ExternDll.Kernel32, SetLastError=true, CharSet=CharSet.Auto, BestFitMapping=false)]
        public static extern IntPtr GetModuleHandle(string modName); 

        [DllImport(ExternDll.User32, SetLastError=true, ExactSpelling=true)] 
        public static extern IntPtr GetProcessWindowStation(); 

        [DllImport(ExternDll.Gdi32, SetLastError=true, EntryPoint="CreateDC", CharSet=System.Runtime.InteropServices.CharSet.Auto)] 
        private static extern IntPtr IntCreateDC(string lpszDriverName, string lpszDeviceName, string lpszOutput, HandleRef /*DEVMODE*/ lpInitData);
        public static IntPtr CreateDC(String lpszDriverName, string lpszDeviceName, string lpszOutput, HandleRef /*DEVMODE*/ lpInitData) {
            return System.Internal.HandleCollector.Add(IntCreateDC(lpszDriverName, lpszDeviceName, lpszOutput, lpInitData), SafeNativeMethods.CommonHandles.HDC);
        } 

        [DllImport(ExternDll.User32, SetLastError=true, CharSet=System.Runtime.InteropServices.CharSet.Auto)] 
        public static extern bool PeekMessage([In, Out] ref SafeNativeMethods.MSG msg, HandleRef hwnd, int msgMin, int msgMax, int remove); 

        [DllImport(ExternDll.User32, SetLastError=true, ExactSpelling=true, CharSet=System.Runtime.InteropServices.CharSet.Ansi)] 
        public static extern bool PeekMessageA([In, Out] ref SafeNativeMethods.MSG msg, HandleRef hwnd, int msgMin, int msgMax, int remove);

        [DllImport(ExternDll.User32, SetLastError=true, ExactSpelling=true, CharSet=System.Runtime.InteropServices.CharSet.Unicode)]
        public static extern bool PeekMessageW([In, Out] ref SafeNativeMethods.MSG msg, HandleRef hwnd, int msgMin, int msgMax, int remove); 

        [DllImport(ExternDll.Gdi32, SetLastError=true, EntryPoint="CreateIC", CharSet=System.Runtime.InteropServices.CharSet.Auto)] 
        private static extern IntPtr IntCreateIC(string lpszDriverName, string lpszDeviceName, string lpszOutput, HandleRef /*DEVMODE*/ lpInitData); 
        public static IntPtr CreateIC(string lpszDriverName, string lpszDeviceName, string lpszOutput, HandleRef /*DEVMODE*/ lpInitData) {
            return System.Internal.HandleCollector.Add(IntCreateIC(lpszDriverName, lpszDeviceName, lpszOutput, lpInitData), SafeNativeMethods.CommonHandles.HDC); 
        }

        public static bool DeleteHDC(HandleRef hDC) {
            System.Internal.HandleCollector.Remove((IntPtr)hDC, SafeNativeMethods.CommonHandles.HDC); 
            return IntDeleteDC(hDC);
        } 
 
        [DllImport(ExternDll.User32, SetLastError=true, ExactSpelling = true)]
        public static extern IntPtr WindowFromDC( HandleRef hDC ); 
#endif

        [DllImport(ExternDll.Gdi32, SetLastError=true, ExactSpelling=true, EntryPoint="CreateCompatibleDC", CharSet=CharSet.Auto)]
        private static extern IntPtr IntCreateCompatibleDC(HandleRef hDC); 
        public static IntPtr CreateCompatibleDC(HandleRef hDC) {
            return System.Internal.HandleCollector.Add(IntCreateCompatibleDC(hDC), SafeNativeMethods.CommonHandles.GDI); 
        } 

        [DllImport(ExternDll.Gdi32, SetLastError=true, ExactSpelling=true, CharSet=CharSet.Auto)] 
        public static extern IntPtr GetStockObject(int nIndex);

        [DllImport(ExternDll.Kernel32, SetLastError=true, CharSet=System.Runtime.InteropServices.CharSet.Auto)]
        public static extern int GetSystemDefaultLCID(); 

        [DllImport(ExternDll.User32, SetLastError=true, ExactSpelling=true, CharSet=System.Runtime.InteropServices.CharSet.Auto)] 
        public static extern int GetSystemMetrics(int nIndex); 

        [DllImport(ExternDll.User32, SetLastError=true, CharSet=CharSet.Auto, BestFitMapping=false)] 
        public static extern bool SystemParametersInfo(int uiAction, int uiParam, [In, Out] NativeMethods.NONCLIENTMETRICS pvParam, int fWinIni);

        [DllImport(ExternDll.User32, SetLastError=true, CharSet=CharSet.Auto, BestFitMapping=false)]
        public static extern bool SystemParametersInfo(int uiAction, int uiParam, [In, Out] SafeNativeMethods.LOGFONT pvParam, int fWinIni); 

        [DllImport(ExternDll.Gdi32, SetLastError=true, ExactSpelling=true, CharSet=System.Runtime.InteropServices.CharSet.Auto)] 
        public static extern int GetDeviceCaps(HandleRef hDC, int nIndex); 

        [DllImport(ExternDll.Gdi32, SetLastError=true, ExactSpelling=true, CharSet=CharSet.Auto)] 
        public static extern int GetObjectType(HandleRef hObject);

        // SECUNDONE : For some reason "PtrToStructure" requires super high permission.. put this
        //           : assert here until we can get a resolution on this. 
        //           : this is ok as long as the lparam is not obtained from external code.
        [ReflectionPermission(SecurityAction.Assert, Unrestricted=true), 
         SecurityPermission(SecurityAction.Assert, Flags=SecurityPermissionFlag.UnmanagedCode)] 
        public static object PtrToStructure(IntPtr lparam, Type cls) {
            return Marshal.PtrToStructure(lparam, cls); 
        }

        // SECUNDONE : For some reason "PtrToStructure" requires super high permission.. put this
        //           : assert here until we can get a resolution on this. 
        //           : this is ok as long as the lparam is not obtained from external code.
        [ReflectionPermission(SecurityAction.Assert, Unrestricted=true), 
         SecurityPermission(SecurityAction.Assert, Flags=SecurityPermissionFlag.UnmanagedCode)] 
        public static void PtrToStructure(IntPtr lparam, object data) {
            Marshal.PtrToStructure(lparam, data); 
        }

        [ComImport(), Guid("0000000C-0000-0000-C000-000000000046"), System.Runtime.InteropServices.InterfaceTypeAttribute(System.Runtime.InteropServices.ComInterfaceType.InterfaceIsIUnknown)]
        public interface IStream { 
             int Read(
                    [In] 
                     IntPtr buf, 
                    [In]
                     int len); 


             int Write(
                    [In] 
                     IntPtr buf,
                    [In] 
                     int len); 

            [return: MarshalAs(UnmanagedType.I8)] 
             long Seek(
                    [In, MarshalAs(UnmanagedType.I8)]
                     long dlibMove,
                    [In] 
                     int dwOrigin);
 
 
             void SetSize(
                    [In, MarshalAs(UnmanagedType.I8)] 
                     long libNewSize);

            [return: MarshalAs(UnmanagedType.I8)]
             long CopyTo( 
                    [In, MarshalAs(UnmanagedType.Interface)]
                      UnsafeNativeMethods.IStream pstm, 
                    [In, MarshalAs(UnmanagedType.I8)] 
                     long cb,
                    [Out, MarshalAs(UnmanagedType.LPArray)] 
                     long[] pcbRead);


             void Commit( 
                    [In]
                     int grfCommitFlags); 
 

             void Revert(); 


             void LockRegion(
                    [In, MarshalAs(UnmanagedType.I8)] 
                     long libOffset,
                    [In, MarshalAs(UnmanagedType.I8)] 
                     long cb, 
                    [In]
                     int dwLockType); 


             void UnlockRegion(
                    [In, MarshalAs(UnmanagedType.I8)] 
                     long libOffset,
                    [In, MarshalAs(UnmanagedType.I8)] 
                     long cb, 
                    [In]
                     int dwLockType); 


             void Stat(
                    [In] 
                     IntPtr pStatstg,
                    [In] 
                     int grfStatFlag); 

            [return: MarshalAs(UnmanagedType.Interface)] 
              UnsafeNativeMethods.IStream Clone();
        }

        internal class ComStreamFromDataStream : IStream { 
            protected Stream dataStream;
 
            // to support seeking ahead of the stream length... 
            long virtualPosition = -1;
 
            internal ComStreamFromDataStream(Stream dataStream) {
                if (dataStream == null) throw new ArgumentNullException("dataStream");
                this.dataStream = dataStream;
            } 

            private void ActualizeVirtualPosition() { 
                if (virtualPosition == -1) return; 

                if (virtualPosition > dataStream.Length) 
                    dataStream.SetLength(virtualPosition);

                dataStream.Position = virtualPosition;
 
                virtualPosition = -1;
            } 
 
            public virtual IStream Clone() {
                NotImplemented(); 
                return null;
            }

            public virtual void Commit(int grfCommitFlags) { 
                dataStream.Flush();
                // Extend the length of the file if needed. 
                ActualizeVirtualPosition(); 
            }
 
            public virtual long CopyTo(IStream pstm, long cb, long[] pcbRead) {
                int bufsize = 4096; // one page
                IntPtr buffer = Marshal.AllocHGlobal(bufsize);
                if (buffer == IntPtr.Zero) throw new OutOfMemoryException(); 
                long written = 0;
                try { 
                    while (written < cb) { 
                        int toRead = bufsize;
                        if (written + toRead > cb) toRead  = (int) (cb - written); 
                        int read = Read(buffer, toRead);
                        if (read == 0) break;
                        if (pstm.Write(buffer, read) != read) {
                            throw EFail("Wrote an incorrect number of bytes"); 
                        }
                        written += read; 
                    } 
                }
                finally { 
                    Marshal.FreeHGlobal(buffer);
                }
                if (pcbRead != null && pcbRead.Length > 0) {
                    pcbRead[0] = written; 
                }
 
                return written; 
            }
 
            public virtual Stream GetDataStream() {
                return dataStream;
            }
 
            public virtual void LockRegion(long libOffset, long cb, int dwLockType) {
            } 
 
            protected static ExternalException EFail(string msg) {
                throw new ExternalException(msg, SafeNativeMethods.E_FAIL); 
            }

            protected static void NotImplemented() {
                throw new ExternalException(SR.GetString(SR.NotImplemented), SafeNativeMethods.E_NOTIMPL); 
            }
 
            public virtual int Read(IntPtr buf, /* cpr: int offset,*/  int length) { 
                //        System.Text.Out.WriteLine("IStream::Read(" + length + ")");
                byte[] buffer = new byte[length]; 
                int count = Read(buffer, length);
                Marshal.Copy(buffer, 0, buf, length);
                return count;
            } 

            public virtual int Read(byte[] buffer, /* cpr: int offset,*/  int length) { 
                ActualizeVirtualPosition(); 
                return dataStream.Read(buffer, 0, length);
            } 

            public virtual void Revert() {
                NotImplemented();
            } 

            public virtual long Seek(long offset, int origin) { 
                // Console.WriteLine("IStream::Seek("+ offset + ", " + origin + ")"); 
                long pos = virtualPosition;
                if (virtualPosition == -1) { 
                    pos = dataStream.Position;
                }
                long len = dataStream.Length;
                switch (origin) { 
                    case SafeNativeMethods.StreamConsts.STREAM_SEEK_SET:
                        if (offset <= len) { 
                            dataStream.Position = offset; 
                            virtualPosition = -1;
                        } 
                        else {
                            virtualPosition = offset;
                        }
                        break; 
                    case SafeNativeMethods.StreamConsts.STREAM_SEEK_END:
                        if (offset <= 0) { 
                            dataStream.Position = len + offset; 
                            virtualPosition = -1;
                        } 
                        else {
                            virtualPosition = len + offset;
                        }
                        break; 
                    case SafeNativeMethods.StreamConsts.STREAM_SEEK_CUR:
                        if (offset+pos <= len) { 
                            dataStream.Position = pos + offset; 
                            virtualPosition = -1;
                        } 
                        else {
                            virtualPosition = offset + pos;
                        }
                        break; 
                }
                if (virtualPosition != -1) { 
                    return virtualPosition; 
                }
                else { 
                    return dataStream.Position;
                }
            }
 
            public virtual void SetSize(long value) {
                dataStream.SetLength(value); 
            } 

            public virtual void Stat(IntPtr pstatstg, int grfStatFlag) { 
                // GpStream has a partial implementation, but it's so partial rather
                // restrict it to use with GDI+
                NotImplemented();
            } 

            public virtual void UnlockRegion(long libOffset, long cb, int dwLockType) { 
            } 

            public virtual int Write(IntPtr buf, /* cpr: int offset,*/ int length) { 
                byte[] buffer = new byte[length];
                Marshal.Copy(buf, buffer, 0, length);
                return Write(buffer, length);
            } 

            public virtual int Write(byte[] buffer, /* cpr: int offset,*/ int length) { 
                ActualizeVirtualPosition(); 
                dataStream.Write(buffer, 0, length);
                return length; 
            }
        }

    } 
}
 
 
// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.

Link Menu

Network programming in C#, Network Programming in VB.NET, Network Programming in .NET
This book is available now!
Buy at Amazon US or
Buy at Amazon UK