Editing-style methods for changing a value of the specified additional string property of the ItemNo-th item..
procedure SetItemExtraStrPropertyEd(ItemNo: Integer;
Prop: TRVExtraItemStrProperty; const Value: TRVUnicodeString;
AutoReformat: Boolean);
procedure SetItemExtraStrPropertyExEd(ItemNo, Prop: Integer;
const Value: TRVUnicodeString; AutoReformat: Boolean);
(introduced in versions 1.9 and 15; changed in version 18)
These methods set a new Value of the item property identified by Prop.
In SetItemExtraStrPropertyEd, Prop's type is TRVExtraItemStrProperty. See information about this type for the list of properties.
In SetItemExtraStrPropertyExEd, Prop's type is Integer. If Prop can be converted to TRVExtraItemStrProperty, SetItemExtraStrPropertyExEd works like SetItemExtraStrPropertyEd. In addition, it supports properties identified by rvespc*** constants
ItemNo – index of the item, from 0 to ItemCount-1.
Items of subdocuments (table cells) are not included in the items range of the main document. For items in cells, activate inplace-editor, select the proper item in the cell (SelSelectionBounds), and call SetItemExtraStrProperty[Ex]Ed of this inplace-editor. Alternatively, you can use SetCurrentItemExtraStrProperty.
If AutoReformat=True, these methods automatically reformat the document and call OnChange.
If AutoReformat=False (this can be useful if you set several properties of an item at once), call Change and reformat the document after it yourself. A reformatting depends on the property:
▪some properties do not require reformatting or repainting;
▪some properties require a local reformatting (for example, "format string" of numbered sequences) (change properties between calls of BeginItemModify and EndItemModify);
▪some properties require a complete reformatting (for example, "sequence name" of numbered sequences) (call Reformat).
Method type: 
editing-style (unlike SetItemExtraStrProperty[Ex]).
When possible, use SetCurrentItemExtraStrProperty[Ex] instead of this method.
See also methods:
▪SetCurrentItemExtraStrProperty[Ex];
▪SetItemExtraIntProperty[Ex]Ed.
See also methods of TCustomRichView: