1定义一个结构

PItemData

 

Type //节点信息

  PItemData=^_ItemData;

    _ItemData=packed record

      S:shortstring;

      i:integer;

      f:double;

      B:boolean;

      P:Pointer;

      Next:PItemData;

end;

2初始化combobox

 ComboBox2.Items.Clear;//清空combobox项

  if SetRule.GetMemType>0 then//从数据库中读出记录

  begin

    Global.DM.Q_Select.First;

    while not Global.DM.Q_Select.Eof do

    begin

      p:=AllocMem(SizeOf(p));//分配内存

      p^.S:=Global.DM.Q_Select.fieldbyname('cardtype').AsString;//复值

      ComboBox2.Items.AddObject(Global.DM.Q_Select.fieldbyname('typename').AsString,TObject(p));//初始化combobox

      Global.DM.Q_Select.Next;

    end;

3 运用combobox的value

SetRule.FenRiseType:=PItemData(ComboBox2.Items.Objects[ComboBox2.ItemIndex])^.s;//给属性复值

得到text 值

ComboBox2.Text

3进行比较

 for i:=0 to ComboBox2.Items.Count-1 do

    begin

      if PItemData(ComboBox2.Items.Objects[i])^.S=SetRule.RiseType  then   //强制转换成PitemData类型

        ComboBox2.ItemIndex:=i;

    end;