You can export a crystal report to a memory pdf this way in ASP.Net:
MemoryStream oStream;
oStream = (MemoryStream)
report.ExportToStream(
CrystalDecisions.Shared.ExportFormatType.PortableDocFormat);
Response.Clear();
Response.Buffer= true;
Response.ContentType = "application/pdf";
Response.BinaryWrite(oStream.ToArray());
Response.End();
If you are using windows forms, you need to use the crystal report viewer control. Here is a tutorial on how to use that control:
http://www.aspfree.com/c/a/.NET/Using-CrystalReportViewer-to-Display-Crystal-Reports-in-Net[
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