Passing Multiple Parameters to a Crystal Report Programmatically

Passing a parameter to a Crystal Report is easy; all you need to do is drop a ready-made parameter field from the Field Explorer to your report and when the report is loaded, the user is asked for the parameter's value automatically.

Passing multiple parameter values to a report programmatically is a bit trickier.

First, you have to use the correct parameter type. In the Field Explorer, add a new parameter and make sure that Allow multiple values and Discrete value(s) are selected. Next, drag the parameter from the Field Explorer on your report. Then open the Select Expert (right-click your report and choose Report | Select Expert...), double-click the field you're setting the parameter for (Country in this example), choose is equal to from the first drop-down, choose your parameter (?Country) from the second drop-down and click OK.

The next step is to add the code that passes the values for the parameters at run-time. The example below uses hard-coded values for a parameter that filters the report based on the country name, but in reality you can substitute these hard-coded values with any values you like. For example, you can retrieve them from a database, a user preference stored in the registry, or retrieve them from text boxes placed on a Windows form. Just make sure that the ParameterFieldName matches the name of the parameter in the Field Explorer (minus the question mark). Don't forget to import the CrystalDecisions.Shared namespace.

Add the following code to the click handler of a button, the load handler of a form, or any other method that is applicable in your situation:

using CrystalDecisions.Shared;
...
private void ParamButton_Click(object sender, System.EventArgs e)
{
  // Create parameter objects
  ParameterFields myParams = new ParameterFields();
  ParameterField myParam = new ParameterField();
  ParameterDiscreteValue myDiscreteValue = new ParameterDiscreteValue();

  // Set the ParameterFieldName to the name of the parameter
  // created in the Field Explorer
  myParam.ParameterFieldName = "Country";
			
  // Add first country
  myDiscreteValue.Value = "USA";
  myParam.CurrentValues.Add(myDiscreteValue);
			
  // Reuse myDiscreteValue, and assign second country
  myDiscreteValue = new ParameterDiscreteValue();
  myDiscreteValue.Value = "Netherlands";
  myParam.CurrentValues.Add(myDiscreteValue);
				
  // Add param object to params collection
  myParams.Add(myParam);
		
  // Assign the params collection to the report viewer
  myCrystalReportViewer.ParameterFieldInfo = myParams;
		
  // Assign the Report to the report viewer.
  // This method uses a strongly typed report,
  // but other methods are possible as well.
  myCrystalReportViewer.ReportSource = MyReportObject;
}

Assigning the ParameterFields object to the ParameterFieldInfo of the CrystalReportViewer object programmatically will also suppress the default dialog asking for parameters that normally appears when you open a report with parameters.


Where to Next?

Wonder where to go next?

Doc ID 310
Full URL https://imar.spaanjaars.com/310/passing-multiple-parameters-to-a-crystal-report-programmatically
Short cut https://imar.spaanjaars.com/310/
Written by Imar Spaanjaars
Date Posted 07/07/2004 02:16
Date Last Updated 11/02/2020 15:48
Date Last Reviewed 06/06/2006 22:35
Listened to when writing Korea by Deftones (Track 8 from the album: White Pony)

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