TdxBackendCustomParameter.IsMultiValueParameter Property

Identifies if the Report or Dashboard parameter can have multiple values.

Declaration

property IsMultiValueParameter: Boolean read;

Property Value

Type	Default	Description
Boolean	False	False Default. Single-value mode. Only the first value within the Values collection is used. Alternatively, you can use the Value property. True Multi-value mode. You can use all values stored in the Values collection.

Remarks

This property corresponds to the Allow multiple values option in the Report Designer or the Allow Multiselect option in the Dashboard Designer:

Report

Dashboard

Code Examples

The following code snippets check if the report parameter is a multi-value parameter and read its default values.

Note

The IsMultiValueParameter property is common to report and dashboard parameters. These examples perform the same operation but use component-specific APIs.

Read Report Parameter Values

Delphi

uses
  dxReport.Control,       // Declares the TdxReportControl class
  dxReport.Parameters,    // Declares the TdxReportParameter class
  dxBackend.Parameters,   // Declares the TdxBackendParameterValue class
  dxMessageDialog;        // Declares the TdxMessageDialogForm class

procedure TForm1.cxButton1Click(Sender: TObject);
var
  AParameter: TdxReportParameter;
  AValue: TdxBackendParameterValue;
  AResponse: TStringBuilder;
begin
  // Find the report parameter with the specified name
  AParameter := dxReportControl1.Parameters.FindParam('countryParameter');
  if AParameter <> nil then
  begin
    // Check if the parameter is a multi-value parameter
    if AParameter.IsMultiValueParameter then
    begin
      AResponse := TStringBuilder.Create;
      try
        AResponse.AppendLine('Multi-value parameter:');
        // List default parameter values
        for AValue in AParameter.Values do
          AResponse.AppendLine('- ' + VarToStr(AValue.Value));
        dxShowMessage(AResponse.ToString);
      finally
        AResponse.Free;
      end;
    end
    else
      dxShowMessage('Single-value parameter: ' + VarToStr(AParameter.Value));
  end
  else
    dxShowMessage('"countryParameter" not found.');
end;

C++

#include "dxReport.Control.hpp"  // Declares the TdxReportControl class
#include "dxReport.Parameters"   // Declares the TdxReportParameter class
#include "dxMessageDialog.hpp"   // Declares the TdxMessageDialogForm class

// Add the following linker directives to the corresponding CPP source file:
#pragma link "dxReport.Control"   // Required to use dxReport.Control.hpp declarations

void __fastcall TForm1::cxButton1Click(TObject* Sender) {
  // Find the report parameter with the specified name
  TdxReportParameter* AParameter =
    dxReportControl1->Parameters->FindParam(L"countryParameter");
  if (AParameter != nullptr) {
    // Check if the parameter is a multi-value parameter
    if (AParameter->IsMultiValueParameter) {
      TStringBuilder* AResponse = new TStringBuilder();
      try {
        AResponse->AppendLine(L"Multi-value parameter:");
        // List default parameter values
        for (int i = 0; i < AParameter->Values->Count; i++)
          AResponse->AppendLine(L"- " + VarToStr(AParameter->Values->Items[i]->Value));
        dxShowMessage(AResponse->ToString());
      }
      __finally {
        delete AResponse;
      }
    }
    else
      dxShowMessage(L"Single-value parameter: " + VarToStr(AParameter->Value));
  }
  else
    dxShowMessage(L"\"countryParameter\" not found.");
}

Read Dashboard Parameter Values

Delphi

uses
  dxDashboard.Control,      // Declares the TdxDashboardControl class
  dxDashboard.Parameters,   // Declares the TdxDashboardParameter class
  dxBackend.Parameters;     // Declares the TdxBackendParameterDataType enum
  dxMessageDialog;          // Declares the TdxMessageDialogForm class

procedure TForm1.cxButton1Click(Sender: TObject);
var
  AParameter: TdxDashboardParameter;
  AValue: TdxBackendParameterValue;
  AResponse: TStringBuilder;
begin
  // Find the dashboard parameter with the specified name
  AParameter := dxDashboardControl1.Parameters.FindParam('countryParameter');
  if AParameter <> nil then
  begin
    // Check if the parameter is a multi-value parameter
    if AParameter.IsMultiValueParameter then
    begin
      AResponse := TStringBuilder.Create;
      try
        AResponse.AppendLine('Multi-value parameter:');
        // List default parameter values
        for AValue in AParameter.Values do
          AResponse.AppendLine('- ' + VarToStr(AValue.Value));
        dxShowMessage(AResponse.ToString);
      finally
        AResponse.Free;
      end;
    end
    else
      dxShowMessage('Single-value parameter: ' + VarToStr(AParameter.Value));
  end
  else
    dxShowMessage('"countryParameter" not found.');
end;

C++

#include "dxDashboard.Control.hpp"      // Declares the TdxDashboardControl class
#include "dxDashboard.Parameters.hpp"   // Declares the TdxDashboardParameter class
#include "dxBackend.Parameters.hpp"     // Declares the TdxBackendParameterDataType enum
#include "dxMessageDialog.hpp"          // Declares the TdxMessageDialogForm class

// Add the following linker directives to the corresponding CPP source file:
#pragma link "dxDashboard.Control"   // Required to use dxDashboard.Control.hpp declarations

void __fastcall TForm1::cxButton1Click(TObject* Sender) {
  // Find the dashboard parameter with the specified name
  TdxDashboardParameter* AParameter =
    dxDashboardControl1->Parameters->FindParam(L"countryParameter");
  if (AParameter != nullptr) {
    // Check if the parameter is a multi-value parameter
    if (AParameter->IsMultiValueParameter) {
      TStringBuilder* AResponse = new TStringBuilder();
      try {
        AResponse->AppendLine(L"Multi-value parameter:");
        // List default parameter values
        for (int i = 0; i < AParameter->Values->Count; i++)
          AResponse->AppendLine(L"- " + VarToStr(AParameter->Values->Items[i]->Value));
        dxShowMessage(AResponse->ToString());
      }
      __finally {
        delete AResponse;
      }
    }
    else
      dxShowMessage(L"Single-value parameter: " + VarToStr(AParameter->Value));
  }
  else
    dxShowMessage(L"\"countryParameter\" not found.");
}