Hi Stefan,

Thanks for your answer. I've taken a look at the links, but they don't provide a clear answer. Let me describe my context better:

Suppose I have a class which contains only a Value property:

public class ItemValue

{

  public decimal Value {get;set;}

}

and a view model class:

public class ViewModel

{

 public ItemValue A {get;set;}

 public ItemValue B {get;set;}

 public ItemValue Result {get;set;}

 private XamCalculationManager calcManager = new XamCalculationManager();

 public ViewModel()

 {

   // how do I configure calcaManager to compute A.Value + B.Value and store the result automatically in Result.Value.

  // ItemValue also implements INotifyPropertyChanged, but I left it out from the example for simplicity.

 }

}

Thanks,

Alex

Hi Dyan,

I've read the help pages, but they didn't help me solve my specific issue, like how to write the formula in my case or how to set-up the references.

I'd like to compute "A.Value + B.Value" and store the result automatically in Result.Value.

Here is my code:

public class CellValue : INotifyPropertyChanged
{
private decimal _value;

public decimal Value

{
get
{
return _value;
}
set
{
_value = value;

if (PropertyChanged != null)
{
PropertyChanged(this, new PropertyChangedEventArgs("Value"));
}
}
}

public event PropertyChangedEventHandler PropertyChanged;
}

public class TestVM
{
public CellValue A { get; set; }
public CellValue B { get; set; }

public CellValue Result { get; set; }

XamCalculationManager cm = new XamCalculationManager();

ItemCalculator icResult;

public TestVM()
{
A = new CellValue();
B = new CellValue();
Result = new CellValue();

A.PropertyChanged += new System.ComponentModel.PropertyChangedEventHandler(obj_PropertyChanged);
B.PropertyChanged += new System.ComponentModel.PropertyChangedEventHandler(obj_PropertyChanged);
Result.PropertyChanged += new System.ComponentModel.PropertyChangedEventHandler(obj_PropertyChanged);

cm.CalculationsCompleted += new EventHandler<EventArgs>(cm_CalculationsCompleted);

//ItemCalculator icA = new ItemCalculator();
//icA.CalculationManager = cm;
//icA.Item = A;
////icA.PropertiesToInclude = "Value";
//icA.ReferenceId = "A";

//ItemCalculation calcA = new ItemCalculation();
//calcA.ReferenceId = "AValue";
//calcA.Formula = "[A.Value] + [B.Value]";
//calcA.TreatAsType = typeof(decimal);
//icA.Calculations.Add(calcA);

//ItemCalculator icB = new ItemCalculator();
//icB.CalculationManager = cm;
//icB.Item = B;
////icB.PropertiesToInclude = "Value";
//icB.ReferenceId = "B";

//ItemCalculation calcB = new ItemCalculation();
//calcB.ReferenceId = "BValue";
//calcB.Formula = "[Value]";
//calcB.TreatAsType = typeof(decimal);
//icB.Calculations.Add(calcB);

icResult = new ItemCalculator();
icResult.CalculationManager = cm;
icResult.Item = this;
icResult.ReferenceId = "Result";

ItemCalculation calcResult = new ItemCalculation();
calcResult.Formula = "[A.Value] + [B.Value]";
calcResult.ReferenceId = "CResult";
//calcResult.TargetProperty = "Value";
calcResult.TreatAsType = typeof(decimal);
icResult.Calculations.Add(calcResult);

}

void cm_CalculationsCompleted(object sender, EventArgs e)
{
CalculationResult result = icResult.Results.FirstOrDefault().Value;

//put a breakpoint above to check the result variable
}

}

Thanks,

Alex

Hi Alex,

Here is a sample code that sums the Values of A and B:

public class TestVM
    {
        public CellValue A { get; set; }
        public CellValue B { get; set; }
        public CellValue Result { get; set; }
 
        XamCalculationManager cm = new XamCalculationManager();
        ItemCalculator icA;
        ItemCalculator icB;
        ItemCalculator icResult;
 
        public TestVM()
        {
            A = new CellValue { Value = 1m };
            B = new CellValue { Value = 2m };
            Result = new CellValue();
 
            icA = new ItemCalculator();
            icA.CalculationManager = cm;
            icA.Item = A;
            icA.ReferenceId = "refA";
 
            icB = new ItemCalculator();
            icB.CalculationManager = cm;
            icB.Item = B;
            icB.ReferenceId = "refB";
 
            icResult = new ItemCalculator();
            icResult.CalculationManager = cm;
            icResult.Item = Result;
 
            ItemCalculation calcResult = new ItemCalculation();
            calcResult.Formula = "[refA/Value] + [refB/Value]";
            calcResult.TargetProperty = "Value";
            calcResult.TreatAsType = typeof(decimal);
            icResult.Calculations.Add(calcResult);
 
            cm.CalculationsCompleted += new EventHandler<EventArgs>(cm_CalculationsCompleted);
        }
        void cm_CalculationsCompleted(object sender, EventArgs e)
        {
            CalculationResult result = icResult.Results.FirstOrDefault().Value;
            //put a breakpoint above to check the result variable
        }
 
    }

Hope this helps!

Thanks,

Diyan Dimitrov

Hi Diyan,

Thanks for your answer ! It works perfectly and this was what I needed. 

One more question:

I saw you are using '/' instead of '.' as property accessor. What if I'd like to access indexed properties or collection items ? What syntax should I use ?

Thanks,

Alex

Hi Alex,

Here is a code snippet of using the ListCalculator and indices:

    public class TestVM
    {
        public CellValue Result { get; set; }
        public List<CellValue> CellValueList { get; set; }
 
        XamCalculationManager cm = new XamCalculationManager();
        ItemCalculator icResult;
        ListCalculator lcCellValueList;
 
        public TestVM()
        {
            Result = new CellValue();
            CellValueList = new List<CellValue> { new CellValue { Value = 1m }, new CellValue { Value = 2m }, new CellValue { Value = 3m } };
 
            lcCellValueList = new ListCalculator();
            lcCellValueList.CalculationManager = cm;
            lcCellValueList.ItemsSource = CellValueList;
            lcCellValueList.ReferenceId = "ListCellValues";
 
            icResult = new ItemCalculator();
            icResult.CalculationManager = cm;
            icResult.Item = Result;
 
            ItemCalculation calcResult = new ItemCalculation();
            calcResult.Formula = "[ListCellValues/Value(0)] + [ListCellValues/Value(2)]";
            calcResult.TargetProperty = "Value";
            calcResult.TreatAsType = typeof(decimal);
            icResult.Calculations.Add(calcResult);
 
            cm.CalculationsCompleted += new EventHandler<EventArgs>(cm_CalculationsCompleted);
        }
        void cm_CalculationsCompleted(object sender, EventArgs e)
        {
            CalculationResult result = icResult.Results.FirstOrDefault().Value;
            //put a breakpoint above to check the result variable
        }
 
    }

Thanks,

Diyan