private CatalogItem[] ReadNameList(IStream catalogHeaderStream, CatalogHeader header)
{
// 在Windows中，文件名最长好像只有256个Unicode字符
// 所以1K的缓存应该很足够了
var buffer = new byte[1024];
var cbRead = Marshal.AllocCoTaskMem(4);
var results = new CatalogItem[header.ThumbCount];
var builder = new StringBuilder();
try
{
for (int i = 0; i < header.ThumbCount; ++i)
{
catalogHeaderStream.Read(buffer, 16, cbRead);
if (Marshal.ReadInt32(cbRead) != 16)
throw new InvalidDataException("文件夹的Thumb.db已经损坏！");
results[i].Reserved1 = BitConverter.ToInt32(buffer, 0);
results[i].ItemId = BitConverter.ToInt32(buffer, 4);
results[i].Modified = DateTime.FromFileTime(
BitConverter.ToInt64(buffer, 8));
Array.Clear(buffer, 0, 16);
do
{
catalogHeaderStream.Read(buffer, 2, cbRead);
builder.Append(BitConverter.ToChar(buffer, 0));
} while (buffer[0] != 0 || buffer[1] != 0);
builder.Length -= 1;
results[i].FileName = builder.ToString();
builder.Remove(0, builder.Length);
catalogHeaderStream.Read(buffer, 2, cbRead);
results[i].Reserved2 = BitConverter.ToInt16(buffer, 0);
Array.Clear(buffer, 0, 2);
}
}
finally
{
Marshal.FreeCoTaskMem(cbRead);
}
return results;
}
private CatalogItem[] InitialThumbNameList(IStorage m_IStorage)
{
IStream catalogHeaderStream;
m_IStorage.OpenStream(CATALOG_HEADER_NAME,
IntPtr.Zero,
(uint)(Win32.STGM.READWRITE | Win32.STGM.SHARE_EXCLUSIVE),
0,
out catalogHeaderStream);
var header = new CatalogHeader();
var size = Marshal.SizeOf(typeof(CatalogHeader));
var buffer = new byte[size];
var cbRead = Marshal.AllocCoTaskMem(4);
try
{
catalogHeaderStream.Read(buffer, size, cbRead);
if (size != Marshal.ReadInt32(cbRead))
throw new InvalidOperationException("在从Thumb.db读取CatalogHeader失败！");
}
finally
{
Marshal.FreeCoTaskMem(cbRead);
}
using (var reader = new BinaryReader(new MemoryStream(buffer)))
{
header.Reserved1 = reader.ReadInt16();
header.Reserved2 = reader.ReadInt16();
header.ThumbCount = reader.ReadInt32();
header.ThumbHeight = reader.ReadInt32();
header.ThumbWidth = reader.ReadInt32();
}
ThumbHeight = header.ThumbHeight;
ThumbWidth = header.ThumbWidth;
return ReadNameList(catalogHeaderStream, header);
}
