Custom Report Item CustomData evaluation problem in a subreport loop

Question

Came across a strange problem with the custom report item CustomData property evaluation when using a sub report loop.
I have a master report, which contains a sub report component within a List. The List is bound to a dataset from which a numeric value is passed on to a sub report's report parameter, and from there further down as an argument to a sub report dataset. The sub
report contains our custom image CRI, which is bound to the said dataset. This dataset outputs a base64 encoded image data value, which the CRI then renders.
Now the problem is that only the first sub report iteration gets evaluated correctly, rest of them seem to get their CRI CustomData from the first iteration. So essentially the loop just outputs the same first sub report over and over again.
However, if I make the List component do a page break after each sub report, then all the sub reports start getting rendered correctly. 
Here's how the CustomData gets initialized in the CRI designer class:
this.CustomData = new CustomData();
this.CustomData.DataRowHierarchy = newDataHierarchy();
this.CustomData.DataRowHierarchy.DataMembers.Add(newDataMember());
this.CustomData.DataRowHierarchy.DataMembers[0].Group = newGroup();
this.CustomData.DataRowHierarchy.DataMembers[0].Group.Name = this.Name + "_SingleGrouping";
this.CustomData.DataRowHierarchy.DataMembers[0].Group.GroupExpressions.Add(new ReportExpression());
this.CustomData.DataColumnHierarchy = new DataHierarchy();
this.CustomData.DataColumnHierarchy.DataMembers.Add(new DataMember());
DataRow row = new DataRow();
DataValue value = new DataValue();
value.Name = "Base64";
value.Value = ""; 
DataCell cell = new DataCell();
cell.Add(value);
row.Add(cell);
this.CustomData.DataRows.Add(row);
The CRI also exposes the CustomData's DataSetName and a Base64 property.
Has anyone else seen something like this happen? Not sure if this could be an issue with our CustomData configuration/usage, the API documentation is pretty much non-existent as usual. Seems more like bug to
me.
Leo Wartinen, Predisys Inc.

Answer 1

Hi WarLe,
If I understand correctly, you are using a list control to contain the subreport in the master report. The dataset of the list contains the field which is passed as the parameter values of the subreport. When you render the report, only the first subreport
gets evaluated correctly, rest of them seem to get their CRI CustomData from the first iteration, right?
If in this scenario, it seems that you haven’t add a group in the list. We can try to add a group grouped on the field which is passed as the parameter values of the subreport to check the issue again. Besides, could you mind post the sample data for the
dataset of the list and tell us the settings for the list control? Then we can make further analysis.
If there are any misunderstanding, please elaborate the issue for further investigation.
Thanks,
Katherine Xiong
Katherine Xiong
TechNet Community Support