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                                László Pétervári 06.16.2012

                                  • Hello!

                                    I have a GridView which has a number of columns bound to several numeric properties (ints, doubles, or so). In my business object I use the extremal number "-1" to represent a "null" value in these numeric properties. That means that if the value is -1, then the property is unknown, not set.

                                    How could I force my columns to treat -1 values as Null values? I need the filter mode set to Value, and SortMode set to Default as well, to let users useing the numeric specific capabilities. I use CustomDisplayText event for replacing -1 values with empty strings, however I still see the -1 in the filter popup for example, and also sorting takes -1 as it is, instead of null.

                                    Thank you,

                                    Zoltán

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                                2 Solutions

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                                László Pétervári 07.07.2012

                                In these situations using a nullable type seems to be a good solution, instead of using not nullable type and a special value to represent "null".

                                • Gosha (DevExpress Support) 07.09.2012

                                  I agree with you that the use of a nullable type is the most appropriate solution here. If it is impossible to change the type of the required field, you can use unbound columns, as I suggested above.

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                                Gosha (DevExpress Support) 06.18.2012

                                The only correct way here is to use unbound columns. I have created a small sample to illustrate this.

                                I hope this information will be helpful to you.

                                dxSample.zip
                                • László Pétervári 07.06.2012

                                  Hello Gosha, sorry for the late reply.
                                  Unfortunately using unbound columns is not an acceptable solution in my real project, because I have several grids with a lot of such numeric columns. I'm completely stuch with this (I think not so uncommon) problem. See also my other post at http://www.devexpress.com/Support/Center/Question/Details/Q414847 for further clarification of my problem.
                                  Thank you!

                                • László Pétervári 07.06.2012

                                  Just now I got an idea. Wouldn't it solve all my problems if I used "double?" instead of "double" for my underlying property? Can a GridView work with nullable types property? I mean sorting and filtering by value.

                                • László Pétervári 07.07.2012

                                  I've tested "double?" instead of using -1, and it looks fine.

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