Comparing date in Conditional Formatting

[Gourangi]

Hi,

I am having problem with conditional formatting feature of telerik reporting for windows application.

(.net framework 2.0 language visual basic 8 and operating system windows xp pro)

I am comparing a datafield and a variable date value and based on that it should filter backcolor of particular textbox which is placed dynamically in detail section of the report.

'FormattingRule1.Filters.AddRange(New Telerik.Reporting.Data.Filter() {New Telerik.Reporting.Data.Filter("=CDate(Fields.S001)", CType(Telerik.Reporting.Data.FilterOperator.GreaterThan, Telerik.Reporting.Data.FilterOperator), "=CDate(""00:07:49"")")})

This is hardcodead things which works fine but if i write these code (below), it throws me an error "Object reference not set to an instance of an object."

Here tItem is a dynamic telerik's reporting textbox
dt.Columns(i).ColumnName is a particular ColumnName which has datetime value and datatype is varchar

    Dim FormattingRule1 As Telerik.Reporting.Drawing.FormattingRule = New Telerik.Reporting.Drawing.FormattingRule
               
    FormattingRule1.Filters.AddRange(New Telerik.Reporting.Data.Filter() {New Telerik.Reporting.Data.Filter("=CDate(""" + averageTime + """)", CType(Telerik.Reporting.Data.FilterOperator.GreaterOrEqual, Telerik.Reporting.Data.FilterOperator), "=CDate(Fields." + dt.Columns(i).ColumnName + ")")})
   
    FormattingRule1.Style.BackgroundColor = System.Drawing.Color.Chocolate
   
    tItem.ConditionalFormatting.AddRange(New Telerik.Reporting.Drawing.FormattingRule() {FormattingRule1})

In short if i replace dt.Columns(i).ColumnName with hardcoaded column name like =CDate(Fields.S001) is not throwing me any error.

It should not be like this.

Help me out.

Thanks

[Gourangi]

Hi,

I found the reason why it was throwing object ref... error.
Actually that datasource which was assigned to it has some values null and there was written like CDate(" + ColumnName + ")" so it could not convert a null value to valid datetime value.

[Svetoslav]

Hello Divyesh,

It's good that you have managed to find out the reason for your troubles. I would suggest that you consider using the ISNULL built-in function:

object IsNull(value, defaultValue)

which returns the defaultValue if the value is null (Nothing in Visual Basic.NET syntax; otherwise returns the value itself).

For a default value you have to consider the most suitable one for your particular case. Since you need to format the TextBox when the current date is greater or equal to a given date, you can use #1-1-1# (January 1st, 0001) which is smaller enough or today's date that you can obtain from the Now() built-in function.

For more information please see Using Expressions.

Sincerely yours,
Svetoslav
the Telerik team

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