Difference between revisions of "LMD VCL - LMD Packs"

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===Using Paste/Copy commands at runtime===
 
===Using Paste/Copy commands at runtime===
 
Copy:
 
Copy:
−
<delphi>
+
<syntaxhighlight lang="delphi">
 
if assigned(LMDShellList1.selected) then
 
if assigned(LMDShellList1.selected) then
−
LMDDoContextMenuVerb( LMDShellList1, (LMDShellList1.Selected as TLMDShellListItem).ShellItem, 'copy');
+
  LMDShellDoContextMenuVerb( LMDShellList1, (LMDShellList1.Selected as TLMDShellListItem).ShellItem, 'copy');
−
</delphi>
+
</syntaxhighlight>
 
Paste:
 
Paste:
−
<delphi>
+
<syntaxhighlight lang="delphi">
−
LMDDoContextMenuVerb( LMDShellList2, LMDShellFolder2.ActiveFolder,'paste');
+
LMDShellDoContextMenuVerb( LMDShellList2, LMDShellFolder2.ActiveFolder,'paste');
−
</delphi>
+
</syntaxhighlight>
  
 
==LMD RichPack==
 
==LMD RichPack==
Line 27: Line 27:
 
===[Linker Error] Unresolved external "InternetCloseHandle" referenced from===
 
===[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<br>  
 
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<br>  
−
<code>#pragma link "wininet.lib"</code><br> in your code.
+
<syntaxhighlight lang="cpp">
−
 
+
#pragma link "wininet.lib"
−
==NG Serialization==
+
</syntaxhighlight> in your code.
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===How to serialize collections===
 
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Serializing collections, including custom or standard collections (like TList) requires writing custom converters. For example, lets consider the folowing collection declaration:
 
−
 
 
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<pre class="brush:delphi">
 
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type
 
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  TItem = class
 
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  public
 
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    X: Integer;
 
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    Y: Integer;
 
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  end;
 
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  TItems = class(TObjectList<TItem>);
 
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</pre>
 
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To be able to serialize it, we need to declare a converter class, and '''associate''' this class with our collection using Converter attribute:
 
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<pre class="brush:delphi">
 
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type 
 
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  TItemsConverter = class(TConverter)
 
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  public
 
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    function  GetReadMode: TReadMode; override;
 
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    procedure Write(S: TSerializer; const V); override;
 
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    procedure Read(D: TDeserializer; var V); override;
 
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  end;
 
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  [Converter(TItemsConverter)]
 
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  TItems = class(TObjectList<TItem>);
 
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</pre>
 
−
 
 
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The converter can be implemented like this:
 
−
 
 
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<pre class="brush:delphi">
 
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function TItemsConverter.GetReadMode: TReadMode;
 
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begin
 
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  Result := rmFillRead; // Indicate fill-read mode.
 
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end;
 
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procedure TItemsConverter.Read(D: TDeserializer; var V);
 
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var
 
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  lst: TItems;
 
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begin
 
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  lst := TItems(V); // Since we work in fill-read mode,
 
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                    // V already contains a reference to
 
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                    // TItems instance; we should not
 
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                    // create it here.
 
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  lst.Clear;
 
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  D.BeginArray;
 
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  while D.HasNext do
 
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    lst.Add(D.Value<TItem>);
 
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  D.EndArray;
 
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end;
 
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procedure TItemsConverter.Write(S: TSerializer; const V);
 
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var
 
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  lst: TItems;
 
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  i:  Integer;
 
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begin
 
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  S.BeginArray;
 
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  lst := TItems(V);
 
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  for i := 0 to lst.Count - 1 do
 
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    S.Value(lst[i]);
 
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  S.EndArray;
 
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end;
 
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</pre>
 
−
 
 
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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:
 
−
 
 
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<pre class="brush:delphi">
 
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type 
 
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  TOwner = class
 
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  private
 
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    FItems: TItems;
 
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  public
 
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    constructor Create;
 
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    destructor  Destroy; override;
 
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    property    Items: TItems read FItems;
 
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  end;
 
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constructor TOwner.Create;
 
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begin
 
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  inherited Create;
 
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  FItems := TItems.Create;
 
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end;
 
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destructor TOwner.Destroy;
 
−
begin
 
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  FItems.Free;
 
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  inherited;
 
−
end;
 
−
</pre>
 
−
 
 
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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:
 
−
 
 
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<pre class="brush:delphi">
 
−
var
 
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  src, dst: TOwner;
 
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  stream:  TStream;
 
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  s:        TBinarySerializer;
 
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  d:        TBinaryDeserializer;
 
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begin
 
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  stream := TMemoryStream.Create;
 
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  try
 
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    src := TOwner.Create;
 
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    src.Items.Add(TItem.Create);
 
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    src.Items.Add(TItem.Create);
 
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    src.Items.Add(TItem.Create);
 
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    s := TBinarySerializer.Create(stream);
 
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    s.Value(src);
 
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    s.Free;
 
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    stream.Position := 0;
 
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    d  := TBinaryDeserializer.Create(stream);
 
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    dst := d.Value<TOwner>;
 
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    d.Free;
 
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  finally
 
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    stream.Free;
 
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  end;
 
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end;
 
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</pre>
 
−
 
 
−
Please use the following link for more information about fill-read mode:
 
−
[http://www.lmd.de/downloads/tutorials/serialization/index.html?fill-read_mode.htm Fill-Read Mode]
 

Latest revision as of 13:09, 28 April 2022

[edit]

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LMD ShellPack

Using Paste/Copy commands at runtime

Copy: 

if assigned(LMDShellList1.selected) then
  LMDShellDoContextMenuVerb( LMDShellList1, (LMDShellList1.Selected as TLMDShellListItem).ShellItem, 'copy');

Paste: 

LMDShellDoContextMenuVerb( LMDShellList2, LMDShellFolder2.ActiveFolder,'paste');

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.
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