BaseCAMarshaler.cs source code in C# .NET

                        Code:
                         / DotNET / DotNET / 8.0 / untmp / whidbey / REDBITS / ndp / fx / src / WinForms / Managed / System / WinForms / ComponentModel / COM2Interop / BaseCAMarshaler.cs / 1 / BaseCAMarshaler.cs
                        
                        
                            //------------------------------------------------------------------------------ 
// 
//     Copyright (c) Microsoft Corporation.  All rights reserved.
// 
//----------------------------------------------------------------------------- 

namespace System.Windows.Forms.ComponentModel.Com2Interop { 
    using System.Runtime.Remoting; 
    using System.Runtime.InteropServices;
    using System.ComponentModel; 
    using System.Diagnostics;
    using System;
    using Microsoft.Win32;
    using System.Globalization; 

 
    ///  
    /// 
    ///   This class performs basic operation for marshaling data passed 
    ///   in from native in one of the CA*** structs (CADWORD, CAUUID, etc),
    ///   which are structs in which the first word is the number of elements
    ///   and the second is a pointer to an array of such elements.
    /// 
    /// 
    internal abstract class BaseCAMarshaler { 
 
        private static TraceSwitch CAMarshalSwitch = new TraceSwitch("CAMarshal", "BaseCAMarshaler: Debug CA* struct marshaling");
 
        private IntPtr caArrayAddress;
        private int count;
        private object[] itemArray;
 
        /// 
        ///  
        ///     Base ctor 
        /// 
        protected BaseCAMarshaler(NativeMethods.CA_STRUCT caStruct) : base() { 
            if (caStruct == null) {
                count = 0;
                Debug.WriteLineIf(CAMarshalSwitch.TraceVerbose, "BaseCAMarshaler: null passed in!");
            } 

            // first 4 bytes is the count 
            count = caStruct.cElems; 
            caArrayAddress = caStruct.pElems;
            Debug.WriteLineIf(CAMarshalSwitch.TraceVerbose, "Marshaling " + count.ToString(CultureInfo.InvariantCulture) + " items of type " + ItemType.Name); 
        }

        ~BaseCAMarshaler() {
            try { 
                if (itemArray == null && caArrayAddress != IntPtr.Zero) {
                     object[] items = Items; 
                } 
            }
            catch { 
            }
        }

        protected abstract Array CreateArray(); 

        ///  
        ///  
        ///     Returns the type of item this marshaler will
        ///     return in the items array. 
        /// 
        public abstract Type ItemType {
            get;
        } 

 
        ///  
        /// 
        ///     Returns the count of items that will be or have been 
        ///     marshaled.
        /// 
        public int Count {
            get { 
                return count;
            } 
        } 

 

        /// 
        /// 
        ///     The marshaled items. 
        /// 
        public virtual object[] Items { 
            get { 
                try {
                    if (itemArray == null) { 
                        itemArray = Get_Items();
                    }
                }
                catch (Exception ex) { 
                    Debug.WriteLineIf(CAMarshalSwitch.TraceVerbose, "Marshaling failed: " + ex.GetType().Name + ", " + ex.Message);
                } 
#if DEBUG 
                if (itemArray != null) {
                    Debug.WriteLineIf(CAMarshalSwitch.TraceVerbose, "Marshaled: " + itemArray.Length.ToString(CultureInfo.InvariantCulture) + " items, array type=" + itemArray.GetType().Name); 
                }
#endif
                return itemArray;
            } 
        }
 
 
        /// 
        ///  
        ///     Override this member to perform marshalling of a single item
        ///     given it's native address.
        /// 
        protected abstract object GetItemFromAddress(IntPtr addr); 

        // Retrieve the items 
        private object[] Get_Items() { 
            // cycle through the addresses and get an item for each addr
            IntPtr addr; 
            Array items = new object[Count]; //cpb vs38262 System.Array.CreateInstance(this.ItemType,count);
            object curItem;
            for (int i = 0; i < count; i++) {
                try { 
                    addr = Marshal.ReadIntPtr(caArrayAddress, i * IntPtr.Size);
                    curItem = GetItemFromAddress(addr); 
                    if (curItem != null && ItemType.IsInstanceOfType(curItem)) { 
                        items.SetValue(curItem, i);
                    } 
                    Debug.WriteLineIf(CAMarshalSwitch.TraceVerbose, "Marshaled " + ItemType.Name + " item, value=" + (curItem == null ? "(null)" : curItem.ToString()));
                }
                catch (Exception ex) {
                    Debug.WriteLineIf(CAMarshalSwitch.TraceVerbose, "Failed to marshal " + ItemType.Name + " item, exception=" + ex.GetType().Name +", " +ex.Message); 
                }
            } 
            // free the array 
            Marshal.FreeCoTaskMem(caArrayAddress);
            caArrayAddress = IntPtr.Zero; 
            return(object[])items;
        }
    }
} 

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.
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BaseCAMarshaler.cs source code in C# .NET

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