title: How can i use listDictionary?
body: <p>i can fill my listdictinary but, if running error returns to me in "   foreach (string ky in ld.Keys)"(invalid operation Exception was unhandled)</p>
  
  <p><b>Error Detail : After creating a pointer to the list of sample collection has been changed. C# </b></p>
  
  <pre><code>       ListDictionary ld = new ListDictionary();
              foreach (DataColumn dc in dTable.Columns)
              {
                  MessageBox.Show(dTable.Rows[0][dc].ToString());
                  ld.Add(dc.ColumnName, dTable.Rows[0][dc].ToString());
              }
  
              foreach (string ky in ld.Keys)
                  if (int.TryParse(ld[ky].ToString(), out QuantityInt))
                      ld[ky] = "integer";
                  else if(double.TryParse(ld[ky].ToString(), out QuantityDouble))
                      ld[ky]="double";
                  else
                      ld[ky]="nvarchar";</code></pre>