LMD VCL - LMD Packs
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LMD ShellPack
Using Paste/Copy commands at runtime
LMD RichPack
Which MS RichEdit DLL Version can I expect on a specific operating system?
Please check list of different RichEdit versions.
Searching for specific attributes
Q: I was trying out the LMD RTF wrapper (using BCB 6) and wanted to know what would be the best way to search for words or characters with a specific attribute.
A:
- Use FindTextEx
- Check SelAttributes
if attrs not ok then FindTextEx again.
LMD WebPack
[Linker Error] Unresolved external "InternetCloseHandle" referenced from
Simply add wininet.lib to your project (file can be found in \lib directory of your C++ Builder / BDS / CRS installation). In recent IDEs you can also add
#pragma link "wininet.lib"
in your code.
NG Serialization
How to serialize collections
Serializing collections, including custom or standard collections (like TList) requires writing custom converters. For example, lets consider the folowing collection declaration:
type TItem = class public X: Integer; Y: Integer; end; TItems = class(TObjectList<TItem>);
To be able to serialize it, we need to declare a converter class, and associate this class with our collection using Converter attribute:
type TItemsConverter = class(TConverter) public function GetReadMode: TReadMode; override; procedure Write(S: TSerializer; const V); override; procedure Read(D: TDeserializer; var V); override; end; [Converter(TItemsConverter)] TItems = class(TObjectList<TItem>);
The converter can be implemented like this:
function TItemsConverter.GetReadMode: TReadMode; begin Result := rmFillRead; // Indicate fill-read mode. end; procedure TItemsConverter.Read(D: TDeserializer; var V); var lst: TItems; begin lst := TItems(V); // Since we work in fill-read mode, // V already contains a reference to // TItems instance; we should not // create it here. lst.Clear; D.BeginArray; while D.HasNext do lst.Add(D.Value<TItem>); D.EndArray; end; procedure TItemsConverter.Write(S: TSerializer; const V); var lst: TItems; i: Integer; begin S.BeginArray; lst := TItems(V); for i := 0 to lst.Count - 1 do S.Value(lst[i]); S.EndArray; end;
As can be seen, GetReadMode returns rmFillRead, which indicates that de-serializer should use fill-read mode. This means that no new TItems instance is created during de-serialization. This mode is especially usefull for collection like classes, because they usually owned by some other objects. For example, lets look at the following class:
type TOwner = class private FItems: TItems; public constructor Create; destructor Destroy; override; property Items: TItems read FItems; end; constructor TOwner.Create; begin inherited Create; FItems := TItems.Create; end; destructor TOwner.Destroy; begin FItems.Free; inherited; end;
As can be seen, TItems collection is oqned by TOwner class. TOwner expose Items as read-only property, and thus, there no way to replace collection as a whole. Only collection content can be changed.
But, fortunately, TOwner class can be serialized and de-serialized, because TItems collection has fill-read mode converter:
var src, dst: TOwner; stream: TStream; s: TBinarySerializer; d: TBinaryDeserializer; begin stream := TMemoryStream.Create; try src := TOwner.Create; src.Items.Add(TItem.Create); src.Items.Add(TItem.Create); src.Items.Add(TItem.Create); s := TBinarySerializer.Create(stream); s.Value(src); s.Free; stream.Position := 0; d := TBinaryDeserializer.Create(stream); dst := d.Value<TOwner>; d.Free; finally stream.Free; end; end;
Please use the following link for more information about fill-read mode: Fill-Read Mode