Using Multiple Columns in Custom Summaries in GridGrouping Control

[Administrator]

Hi,

I''m trying to create a custom summary that provides a weighted average. In the ISummary:CreateSummaryMethod() of my custom summary implementation I need way of accessing a field that isn''t the field being summarized. Is it possible to do this?

Thanks,

Ben.

[Administrator]

Hi Ben,

you can access any field (or multiple fields) from the record.

See this example:

		public static ISummary CreateSummaryMethod(SummaryDescriptor sd, Record record)
		{
			object obj = record.ParentTableDescriptor.Fields["Weight"].GetValue(record);
			// -or -
			// you could also access values from outside the table here, e.g. a external table 
			// of weights. You only need to make sure then that if you change values in the external table
			// that you then call InvalidateSummariesTopDown on the grids Table object.

			bool isNull = (obj == null || obj is DBNull);
			if (isNull)
				return Empty;
			else
			{
				double val = Convert.ToDouble(obj);
				return new TotalSummary(val);
			}
		}

Stefan

[Administrator]

Hi Stefan,

Implemented this and it does exactly what I need.

Many thanks,

Ben.

[Mohammed Sharikh]

Hi,

Could you please post the implementation of the weighted average custom summary? I am having problems getting it to work because the docs don''t describe how to use custom summary delegates..

>Hi Stefan,
>
>Implemented this and it does exactly what I need.
>
>Many thanks,
>
>Ben.

[Administrator]

Hi Mohammed, I am sorry for the delay in responding. Attached is a sample that implements the Weighted Mean Custom Summary. Let us know if you have any further queries. Regards, Calvin.

17230.zip