I am trying to write an application that allows me to dynamically load
selected Crystal Report files, read the parameters from the report file,
give the user a chance to enter relevant data in a user friendly manner and
then run the report in a report viewer.

I can find bits and pieces of the instructions for doing this, but I don't
seem to be able to put it all together. For now I have some code that will
show a file Open dialog and let me select the report file. The next step I
believe is to load that file into a Report document. Once the document is
loaded, then I should be able to access its parameterFieldInfo. Here is
code I have cobbled together so far:
// I open the dialog by clicking a command button
private void button1_Click(object sender, System.EventArgs e)

{

// Displays an OpenFileDialog so the user can select a Cursor.

OpenFileDialog openFileDialog1 = new OpenFileDialog();

openFileDialog1.Filter = "Report Files (*.rpt)|*.rpt";

openFileDialog1.Title = "Select a Report File";

// Show the Dialog.

// If the user clicked OK in the dialog and a .RPT file was selected, then
open it.

if (openFileDialog1.ShowDialog() == DialogResult.OK)

{

// I thought the next line of code would load the file into the Report
Dcoument, but I get the error below.

//An unhandled exception of type 'System.NullReferenceException' occurred in
ReportManager.exe

ReportDocument1.Load(openFileDialog1.FileName);

//I am not quite sure how to access the values in the parameter fields They
are part of the Crystal Report Engine DataDefinition object, and so is the
Report document, but I don't understand the link..

for( int i =0 ;i< dataDef1.ParameterFields.Count;i++)

{

listBox1.Items.Add(dataDef1.ParameterFields.Current.ToString());

dataDef1.ParameterFields.MoveNext();

}

}

}

Hi
look at this sample in this link that describes How to create a Dynamic
report using C#. I would say this could be all what you need to know
<http://support.crystaldecisions.com/...es/csharp_win_
dynamic_report_formula.exe.asp>
If you are using The Microsoft SQL server Database these also are very good
samples

<http://support.crystaldecisions.com/...es/csharp_web_
simplelogonviewer.exe.asp>
<http://support.crystaldecisions.com/...es/csharp_win_
dbengine.exe.asp>
Mohamed M .Mahfouz
Developer Support Engineer
ITWorx on behalf of Microsoft EMEA GTSC

Please, when you post code to newsgroups, try to make it as complete as
possible.

Somewhere in your code you declare:

ReportDocument ReportDocument1.

apparently you are missing the following:

ReportDocument1 = new ReportDocument();

(I can't really tell because you didn't post the declaration.) After
you've done this, then you can say:

ReportDocument1.Load(openFileD*ialog1.FileName);

and it should work.

As for the parameter definitions, you should be able to say:

foreach (ParameterFieldDefinition parm in
ReportDocument1.DataDefinition.ParameterFields)
{
listBox1.Items.Add(parm.Name);
// ...or do whatever you like with the parameter here...
}