Defines a class which accepts a writer and uses it to write heterogeneous collections (collections that contain items of different item classes.
 Note
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This class can only read and write heterogeneous collections at the TOP level. If a heterogeneous collection contains a heterogeneous collection property, you need to DefineProperty again.
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Namespace: GStreams
TObject
GStreams.TGSpecialFiler
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Delphi
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type
TGSpecialFiler = class
end;
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Name
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Description
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Create
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Overloaded. Constructs the special Filer object
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Create(TReader)
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Overloaded. Constructs the special filer object and prepares it for reading.
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Create(TWriter)
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Overloaded. Constructs the special filer object and prepares it for writing.
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Top
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All collection item classes must be defined with RegisterClass.
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To use:
For the class that has the heterogeneous collection property:
•Make the Collection property Stored False
• Make DefineProperties, LoadXXXProperty and StoreXXXProperty methods for the class that owns the collection |
Delphi
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procedure DefineProperties(Filer: TFiler); override;
begin
inherited DefineProperties(Filer);
Filer.DefineProperty( 'HPresets',
LoadPresetsProperty, StorePresetsProperty,
Presets.Count > 0 );
end;
procedure LoadPresetsProperty(Reader: TReader);
var
Filer: TGSpecialFiler;
begin
Filer := TGSpecialFiler.Create(Reader);
try
Filer.ReadCollection(Presets);
finally
Filer.Free;
end;
end;
procedure StorePresetsProperty(Writer: TWriter);
var
Filer: TGSpecialFiler;
begin
Filer := TGSpecialFiler.Create(Writer);
try
Filer.WriteCollection(Presets);
finally
Filer.Free;
end;
end;
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