title: Expression of type 'System.Decimal' cannot be used for parameter of type 'System.Object' of
body: <p>I'm getting the below error messagE:</p>
  
  <pre><code>Expression of type 'System.Decimal' cannot be used for parameter of type 'System.Object' of method 'System.String Format(System.String, System.Object)'
  </code></pre>
  
  <p>When using the below expression:</p>
  
  <pre><code>var expression = "iif({0}.HasValue, String.Format('{0:0.00}%', {0}.Value), 'NA')";
  </code></pre>
  
  <p>This is used for setting Expression property of GridCalculatedColumn which will be added to my GridTableView:</p>
  
  <pre><code>var calculatedColumn = new GridCalculatedColumn
              {
                  DataFields = dataFields,               
                  Expression = expression,                
              };
  </code></pre>
  
  <p>How to convert decimal expression to object expression here?</p>
  
  <p>Thanks</p>