EncoderParameters.cs source code in C# .NET

Source code for the .NET framework in C#

                        
Code:

                         / 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / CommonUI / System / Drawing / Advanced / EncoderParameters.cs / 1305376 / EncoderParameters.cs
                        

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

namespace System.Drawing.Imaging { 
    using System.Text; 
    using System.Runtime.InteropServices;
 
    using System.Diagnostics;
    using System.Diagnostics.CodeAnalysis;

    using System; 
    using System.Drawing.Internal;
    using Marshal = System.Runtime.InteropServices.Marshal; 
    using System.Drawing; 

    //[StructLayout(LayoutKind.Sequential)] 
    /// 
    /// 
    ///    [To be supplied.]
    ///  
    public sealed class EncoderParameters : IDisposable {
        EncoderParameter[] param; 
 
        /// 
        ///  
        ///    [To be supplied.]
        /// 
        public EncoderParameters(int count) {
             param = new EncoderParameter[count]; 
        }
 
        ///  
        /// 
        ///    [To be supplied.] 
        /// 
        public EncoderParameters() {
             param = new EncoderParameter[1];
        } 

        ///  
        ///  
        ///    [To be supplied.]
        ///  
        public EncoderParameter[] Param {
            //

            get { 
                return param;
            } 
            set { 
                param = value;
            } 
        }

        /// 
        ///     Copy the EncoderParameters data into a chunk of memory to be consumed by native GDI+ code. 
        ///
        ///     We need to marshal the EncoderParameters info from/to native GDI+ ourselve since the definition of the managed/unmanaged classes 
        ///     are different and the native class is a bit weird. The native EncoderParameters class is defined in GDI+ as follows: 
        ///
        ///      class EncoderParameters { 
        ///          UINT Count;                      // Number of parameters in this structure
        ///          EncoderParameter Parameter[1];   // Parameter values
        ///      };
        /// 
        ///     We don't have the 'Count' field since the managed array contains it. In order for this structure to work with more than one
        ///     EncoderParameter we need to preallocate memory for the extra n-1 elements, something like this: 
        /// 
        ///         EncoderParameters* pEncoderParameters = (EncoderParameters*) malloc(sizeof(EncoderParameters) + (n-1) * sizeof(EncoderParameter));
        /// 
        ///     Also, in 64-bit platforms, 'Count' is aligned in 8 bytes (4 extra padding bytes) so we use IntPtr instead of Int32 to account for
        ///     that (See VSW#451333).
        /// 
        internal IntPtr ConvertToMemory() { 
            int size = Marshal.SizeOf(typeof(EncoderParameter));
 
            IntPtr memory = Marshal.AllocHGlobal(param.Length * size  + Marshal.SizeOf(typeof(IntPtr))); 

            if (memory == IntPtr.Zero){ 
                throw SafeNativeMethods.Gdip.StatusException(SafeNativeMethods.Gdip.OutOfMemory);
            }

            Marshal.WriteIntPtr(memory, (IntPtr) param.Length); 

            long arrayOffset = (long) memory + Marshal.SizeOf(typeof(IntPtr)); 
 
            for (int i=0; i 
        ///     Copy the native GDI+ EncoderParameters data from a chunk of memory into a managed EncoderParameters object. 
        ///     See ConvertToMemory for more info.
        ///  
        [SuppressMessage("Microsoft.Performance", "CA1808:AvoidCallsThatBoxValueTypes")]
        internal static EncoderParameters ConvertFromMemory(IntPtr memory) {
            if (memory == IntPtr.Zero) {
                throw SafeNativeMethods.Gdip.StatusException(SafeNativeMethods.Gdip.InvalidParameter); 
            }
 
            int count = Marshal.ReadIntPtr(memory).ToInt32(); 

            EncoderParameters p = new EncoderParameters(count); 
            int size = Marshal.SizeOf(typeof(EncoderParameter));
            long arrayOffset = (long)memory + Marshal.SizeOf(typeof(IntPtr));

            for (int i=0; i 
        public void Dispose() {
            foreach (EncoderParameter p in param) { 
                if( p != null ){
                    p.Dispose();
                }
            } 
            param = null;
        } 
    } 
}
 

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.

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