如何将对象添加到CComboBox

我已声明我的CComboBox如下:

     final CCombo combobox= new CCombo(shell, SWT.BORDER);
     combobox.setBounds(30, 22, 88, 21);

     ResultSet result = statement.executeQuery();

我想将类myCombo的对象添加到combobox

     while(result.next())
     {
          String ProName=result.getString(1);
          String ProId=result.getString(2);
          myCombo comboItem=new myCombo(ProId,ProName); //OBJECT comboItem
          combobox.addElement(comboItem); //ERROR The method addElement(myCombo)  
                                             is undefined for the type CCombo
      } 

组合框中出错。 add元素 (组合项)。。。。但addElement()已在CCombo中定义。

这是类myCombo

class myCombo{
               private String ProId;
               private String ProName;


               public myCombo(String ProId, String ProName) {
                   this.ProId=ProId;
                   this.ProName=ProName;

               }

               public String getProductName() {
                      return ProName;
                   }

               public String getProductId() {
                      return ProId;
                   }

                   @Override
               public String toString() {
                      return ProName;
               }
        }

如何取回选定的数据。
将ERROR显示为铁路超高

combobox.addSelectionListener(new SelectionAdapter() {
            @Override
            public void widgetSelected(SelectionEvent e) {



    myCombo item = (myCombo) combo.getItem(getSelectionIndex()) ; //ERROR

                    if (item!=null) {
                       System.out.printf("You've selected Product Name: %s, Product ID: %s%n", 
                             item.getProductName(), item.getProductId());
                    }

            }
        });