> What is the difference between User Mask and Mask String and

"User Mask" allows you define your own mask characters. Look at the
Hex Entry sample. It has a "User Mask" of:
X[0-9A-F]

which defines "x" or "X" as a user defined mask character which will
accept any characters from the set 0..9 and A..F. "x" is for
optional, "X" is for mandatory.

> what EditMaskMode should I use with IBO ?

Whatever one suits your purpose. Each mode has its own prefix string
which allows the mask processor to determine how it should be handled.

eg.

FieldsEditMask
CurrencyField=::NM::!\$-999],999],990!.00;0;0;0
TextField=::EM::["ccc[-ccc[-ccc]";0;_


A mask is made up of sections. The standard VCL masks have only three
sections, Enh masks have upto five sections (six if you count the
prefix definition).

The first section is the mask string itself.
The second section is either 0 or 1 to indicate whether literals are
saved
The third section indicates what characters represent unfilled
positions in the edit control
the forth section indicates what chaacters represent unfilled
positions in the saved text
the fifth section can define user mask characters

You could also say that there is a "zero section" for IBO masks, which
is the prefix indicating the mask mode to be used.

The dialog that you show from the TEditEnh.EditMask property editor
splits each of those sections into separate controls to make it easy
to see and manage. The "SetEditMaskEx" control on the dialog shows
all the sections joined back together as required for use in the
FieldsEditmask property.


hth

--
Geoff Worboys
Telesis Computing