Filter Descriptor on Nullable fields

[Tony]

Using this  example as our template......
http://demos.telerik.com/silverlight/#GridView/Search

we are having an issue --- if the database field is defined as 'nullable' an exception is occurring

on the line 

 convertedValue = Convert.ChangeType(FilterValue, descriptor.MemberType, CultureInfo.CurrentCulture);

The exception is:
cannot convert string to Nullable<Decimal>

How do we fix this issue? (Entire function is listed below)
Tony



private void UpdateCompositeFilterValues()
       {
           foreach (FilterDescriptor descriptor in _compositeFilterDesriptor.FilterDescriptors)
           {
               if (descriptor.MemberType == null) continue;

               var convertedValue = DefaultValue(descriptor.MemberType);

               try
               {
                   convertedValue = Convert.ChangeType(FilterValue, descriptor.MemberType, CultureInfo.CurrentCulture);
                  ********************************************************************
                   Exception here: cannot convert string to Nullable<Decimal>
                    ********************************************************************************************************
               }
               catch (Exception e)
               {
                   Logger.Error("CreateFilterExpression " + e.Message);
               }

               if (descriptor.MemberType.IsAssignableFrom(typeof(DateTime)))
               {
                   DateTime date;
                   if (DateTime.TryParse(FilterValue, out date))
                   {
                       convertedValue = date;
                   }

               }

               descriptor.Value = convertedValue;

           }
       }

[Rossen Hristov]

Hello Tony,

Could you please send us a runnable sample project that exhibits this behavior. This will save a lot of time.

All the best,
Ross
the Telerik team

[Peter Huisman]

Has this been followed up / solved?

I am getting the same error.

[Rossen Hristov]

Hi Tony,

You can add a check that if the string is null or empty you should assign null to the convertedValue variable. Maybe this will help. When do you get the exception, i.e. what are the values of all variables on the line where the exception is thrown? You can use the debugger, see their values and add the appropriate check.

Greetings,
Ross
the Telerik team

[Bastien]

Same error... any solution found?

I try to put something like that, but it doesn't work:

if(descriptor.MemberType.Equals(typeof(string)))
    convertedValue = Convert.ChangeType(this.FilterValue, descriptor.MemberType, CultureInfo.CurrentCulture);

[Bastien]

no workaround yet?

[Rossen Hristov]

Hi,

Unfortunately, I cannot tell what is going on in your project, unless I have something that I can actually debug. 

If you send me a small sample dummy project that exhibits the behavior you are faced with, I can take a look at it to see what is going on.

Best wishes,

Ross
the Telerik team

[Steven]

Hi,

Convert.ChangeType does not support Nullable thus you get an exception on your column of Nullable values.

Does anyone have a fix?

Regards,
S