コード例 #1
0
    internal static GifPropertyItem[] ConvertFromMemory(IntPtr propdata, int count)
    {
        var props = new GifPropertyItem[count];

        for (var i = 0; i < count; i++)
        {
            GifPropertyItemInternal propcopy = null;
            try
            {
                propcopy = (GifPropertyItemInternal)InteropMethods.PtrToStructure(propdata,
                                                                                  typeof(GifPropertyItemInternal));

                props[i] = new GifPropertyItem
                {
                    Id    = propcopy.id,
                    Len   = propcopy.len,
                    Type  = propcopy.type,
                    Value = propcopy.Value
                };

                // this calls Marshal.Copy and creates a copy of the original memory into a byte array.

                propcopy.value = IntPtr.Zero; // we dont actually own this memory so dont free it.
            }
            finally
            {
                propcopy?.Dispose();
            }

            propdata = (IntPtr)((long)propdata + Marshal.SizeOf(typeof(GifPropertyItemInternal)));
        }

        return(props);
    }
コード例 #2
0
    internal static GifPropertyItemInternal ConvertFromPropertyItem(GifPropertyItem propItem)
    {
        var propItemInternal = new GifPropertyItemInternal
        {
            id   = propItem.Id,
            len  = 0,
            type = propItem.Type
        };

        var propItemValue = propItem.Value;

        if (propItemValue != null)
        {
            var length = propItemValue.Length;
            propItemInternal.len   = length;
            propItemInternal.value = Marshal.AllocHGlobal(length);
            Marshal.Copy(propItemValue, 0, propItemInternal.value, length);
        }

        return(propItemInternal);
    }