DisplayControl property on a field using DAO in C#

[Guest]

Hello,

I am trying to set the DisplayControl property on a field using DAOin
C#. I've found lots of sample code for VB and am trying to adapt it
for use in C#.

This is the code I'm running now:

DAO.Field f = db.TableDefs[TableName].Fields­[ColumnName];

//110 is list box
DAO.Property p1 = f.CreateProperty("DisplayContr­ol", Type.Missing ,
110, Type.Missing);
f.Properties.Append( p1 );

This is the error:

[COMException (0x800a0d3a): Property 'Value' must be set before using
this method.] DAO.Properties.Append(Object Object) +0

The third parameter in the CreateProperty method is the value, so I
don't know why it's not being set.

Any help figuring this out would be greatly appreciated.

 

[Paul Overway]

You're not likely to get much help with C# in this forum....VBA? Yes.

Even though the error says Value, I'd suspect the Type parameter. Try
passing a 3 for the Type parameter.

 

[Guest]

Thanks for the tip. Unfortunately, using 3 for the type causes another
runtime exception:
[COMException (0x800a0d5d): Data type conversion error.]
DAO.FieldClass.CreateProperty(Object Name, Object Type, Object Value,
Object DDL) +0

I tried a few other values including
System.Type.GetType("System.Int32")
System.Type.GetTypeCode(System.Type.GetType("System.Int32"))

This is the line of code:
DAO.Property p1 = f.CreateProperty("DisplayControl",
System.Type.GetTypeCode(System.Type.GetType("System.Int32")) , 110,
Type.Missing);
f.Properties.Append( p1 );


Does anyone know what this parameter is expecting to recieve or have
recomendations about where to look to find info on this question?

Thanks!

You're not likely to get much help with C# in this forum....VBA? Yes.

Even though the error says Value, I'd suspect the Type parameter. Try
passing a 3 for the Type parameter.

--
Paul Overway
Logico Solutions
http://www.logico-solutions.com

Hello,

I am trying to set the DisplayControl property on a field using DAOin
C#. I've found lots of sample code for VB and am trying to adapt it
for use in C#.

This is the code I'm running now:

DAO.Field f = db.TableDefs[TableName].Fields­[ColumnName];

//110 is list box
DAO.Property p1 = f.CreateProperty("DisplayContr­ol", Type.Missing ,
110, Type.Missing);
f.Properties.Append( p1 );

This is the error:

[COMException (0x800a0d3a): Property 'Value' must be set before using
this method.] DAO.Properties.Append(Object Object) +0

The third parameter in the CreateProperty method is the value, so I
don't know why it's not being set.

Any help figuring this out would be greatly appreciated.

 

[Mark Burns via AccessMonster.com]

The problem appears to be with the CreateProperty call.
A few key points from The Access 2002 help for this read:
(Comments inline below denoted thus: <*** my stuff ***>)
<quote>
CreateProperty Method

Creates a new user-defined Property object (Microsoft Jet workspaces only).

Syntax

Set property = object.CreateProperty (name, type, value, DDL)

The CreateProperty method syntax has these parts.

Part Description
name Optional. A Variant (String subtype) that uniquely names the new
Property object.

type Optional. A constant that defines the data type of the new Property
object. See the Type property for valid data types.
<*** this will need to be a type as defined in the DAO .DLL, a DataTypeEnum
- not a .net system.(whatever) framework type ***>

value Optional. A Variant containing the initial property value. See the
Value property for details.

DDL Optional. A Variant (Boolean subtype) that indicates whether or not the
Property is a DDL object. The default is False. If DDL is True, users can't
change or delete this Property object unless they have dbSecWriteDef
permission.
<*** Shouldn't you be setting this TRUE for your purposes here? ***>

Remarks
<snip>
Note If you omit the DDL argument, it defaults to False (non-DDL). Because
no corresponding DDL property is exposed, you must delete and re-create a
Property object you want to change from DDL to non-DDL.
</quote>

 

[Guest]

Thank you so much! That was exactly the information I needed.