I used iReport and i study jasper studio. How transfert iReport reports to jasper studio reports ?
All my reports in iReport
I haven't used iReport, but have you tried transferring the XML from iReport to Jasper Studio? Create a dummy report in Jasper Studio (just run through wizard, create a report using A4 page with empty source, click finish), and then copy the XML from iReport and paste it into the "Source" tab XML for Jasper Studio.
iReport is using older version of JasperReports library which is not 100% compatibility with the default Jaspersoft Studio library.
Have you tried specifying JasperReports library version in Jaspersoft Studio to match those of iReports?
From the Jaspersoft Studio menu, select "Window" - > "Preferences". Select "Jaspersoft Studio" -> "Compatibility". In "Source .jrxml Version, pull down "Version" and select the version of iReport.