LoadPrepared throws ArgumentOutOfRangeException

obulix · October 2024

i have a very simple report created using FastReport .NET v 2024.2.0 community edition.

When i try to generate the below code it throws error at report.LoadPrepared method.

Exception details

System.AggregateException: 'One or more errors occurred. (startIndex cannot be larger than length of string. (Parameter 'startIndex'))'

ArgumentOutOfRangeException: startIndex cannot be larger than length of string. (Parameter 'startIndex')

Here is the code.

string epcdJsonString = File.ReadAllText(".\\ReportTemplate\\SampleJson.json");

RegisteredObjects.AddConnection(typeof(JsonDataConnection));

JsonDataSourceConnection jsonDataSourceConnection = new JsonDataSourceConnection();

jsonDataSourceConnection.ConnectionString = epcdJsonString;

jsonDataSourceConnection.CreateAllTables();

Report report = new Report();

report.LoadPrepared(".\\ReportTemplate\\TestReport.frx");

report.Dictionary.Connections.Add(jsonDataSourceConnection);

report.RegisterData(jsonDataSourceConnection.DataSet);

report.Prepare();

What am i missing here.. the json structure is same as what i have used in the designer.

Note : I am able to preview the report properly in the designer.

Plus Validate Report does not show any error.

stg · 9:19AM

Hello!

The cause of the error in the line `report.LoadPrepared(‘.\\ReportTemplate\\TestReport.frx’);` is that the `LoadPrepared(...)` method is intended only for report files that have already been prepared (.fpx – `SavePrepared`), not for .frx templates.

To load a .frx template and populate it with JSON data via JsonDataSourceConnection, use report.Load(...) and call RegisterData after the template has been loaded:

string json = File.ReadAllText(@‘.\ReportTemplate\SampleJson.json’);
RegisteredObjects.AddConnection(typeof(JsonDataSourceConnection));

var conn = new JsonDataSourceConnection { ConnectionString = json };
conn.CreateAllTables();

using var report = new Report();
report.Load(@‘.\ReportTemplate\TestReport.frx’);
report.Dictionary.Connections.Add(conn);
report.RegisterData(conn.DataSet);
report.Prepare();

LoadPrepared throws ArgumentOutOfRangeException

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