TdxCustomDashboardControl.Parameters Property

Provides access to the collection of dashboard parameters.

Declaration

property Parameters: TdxDashboardParameters read;

Property Value

Type	Description
TdxDashboardParameters	A dashboard parameter collection.

Remarks

The collection accessible through the Parameters property is populated automatically with dashboard parameters stored within dashboard layout definition.

Note

The Parameters property provides access to a read-only dashboard parameter collection. If the list of parameters changes within the dashboard layout definition, the collection is updated automatically the next time you access it in code.

Available Options

You can use the ParamByName property to access a stored parameter by name. In addition, you can use the Parameters.Items property to access all parameters stored in the collection.

Refer to the TdxDashboardParameters class description for detailed information on all available options.

BeginUpdate/EndUpdate and Batch Parameter Changes

Every time you modify a parameter stored within the Parameters collection, the State property value is updated and the TdxDashboardControl component redraws content to reflect the change. Enclose multiple parameter changes between Parameters.BeginUpdate and Parameters.EndUpdate procedure calls to avoid UI flickering due to excessive redraw operations and to improve performance.

Code Examples

List Dashboard Parameter Labels

Delphi

uses
  dxDashboard.Control,      // Declares the TdxDashboardControl class
  dxDashboard.Parameters,   // Declares the TdxDashboardParameter class
  dxMessageDialog,          // Declares the TdxMessageDialogForm class
  System.StrUtils;          // Provides advanced string management routines

procedure TForm1.cxButton1Click(Sender: TObject);
var
  AList: TStringList;
  AParameter: TdxDashboardParameter;
begin
  // Create a TStringList instance
  AList := TStringList.Create;
  try
    // Iterate through dashboard parameters
    for AParameter in dxDashboardControl1.Parameters do
      AList.Add(Format('- %s', [
        // Use the parameter Name if Description is missing
        IfThen(AParameter.Description <> '', AParameter.Description, AParameter.Name)
      ]));
    // Display the parameter list or a notification message if the list is empty
    if AList.Count > 0 then
      dxShowMessage(AList.Text)
    else
      dxShowMessage('The dashboard has no parameters.');
  finally
    AList.Free;
  end;
end;

C++

#include "dxDashboard.Control.hpp"      // Declares the TdxDashboardControl class
#include "dxDashboard.Parameters.hpp"   // Declares the TdxDashboardParameter class
#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) {
  TStringList* AList = new TStringList();
  try {
    // Iterate through dashboard parameters
    for (int i = 0; i < dxDashboardControl1->Parameters->Count; i++) {
      TdxDashboardParameter* AParameter = dxDashboardControl1->Parameters->Items[i];
      UnicodeString ALabel;
      // Use the parameter Name if Description is missing
      if (AParameter->Description.IsEmpty())
        ALabel = AParameter->Name;
      else
        ALabel = AParameter->Description;
      AList->Add(Format(L"- %s", ARRAYOFCONST((ALabel))));
    }
    // Display the parameter list or a notification message if the list is empty
    if (AList->Count > 0)
      dxShowMessage(AList->Text);
    else
      dxShowMessage(L"The dashboard has no parameters.");
  }
  __finally {
    delete AList;
  }
}

Related GitHub-Hosted Example Projects

View Example: Pass a Hidden Dashboard Parameter to a SQL Query