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TAdsStringField Advantage TDataSet Descendant |
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TAdsStringField Advantage TDataSet Descendant |
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The TAdsStringField is a descendant of TStringField, and contains Advantage-specific properties and methods.
Unit
AdsData
Description
TAdsStringField is the default field class used for fields of the type ftString. It is a descendant of the TStringField class, so all existing TDataSet functionality specific to TStringField is still possible when using a TAdsStringField.
You do not have to explicitly choose to use a TAdsStringField. When a table with string fields is opened a TAdsStringField object is created for each string field automatically.
The only exception to this rule is if you are using persistent fields. If you are using persistent fields, and your string field is defined as a TStringField, then you will not automatically be using a TAdsStringField. If you need access to TAdsStringField-specific properties or methods change the persistent field definition to declare the field as a TAdsStringField.
Example
The following example shows how a TField object from the dataset’s Fields collection can be cast to a TAdsStringField in order to access a TAdsStringField-specific property.
for i := 0 to ( CodeTable.Fields.Count - 1 ) do
begin
if ( CodeTable.Fields[i] is TAdsStringField ) and
( TAdsStringField( CodeTable.Fields[i] ).CaseInsensitive ) then
begin
Result := TRUE;
exit;
end;
end;
The as operator could be used as well. For example:
(adstable1.fields[1] as TAdsStringField).CaseInsensitive