combobox的级联问题(100分)

数据库设计这样 <br>中东 &nbsp;沙特 <br>中东 &nbsp;科威特 <br>亚洲 &nbsp;中国 <br>亚洲 &nbsp;日本 <br>用两个combobox,第一个combobox1中可以选择的是中东和亚洲，若combobox1选中中东，则combobox2才可用并只能出现沙特、科威特 &nbsp;<br>如何实现？ <br>我自己写的在combobox1中选择中东后，在combobox2中只出现一条记录，不知是什么原因？

用ComboBox的onchange事件<br>procedure TForm1.ComboBox1Change(Sender: TObject);<br>begin<br>&nbsp; with adq do<br>&nbsp; begin<br>&nbsp; &nbsp; Close;<br>&nbsp; &nbsp; sql.clear;<br>&nbsp; &nbsp; sql.add('查询语句');<br>&nbsp; &nbsp; Open;<br>&nbsp; &nbsp; if isempty then<br>&nbsp; &nbsp; &nbsp; showmessage('该数据为空')<br>&nbsp; &nbsp; else<br>&nbsp; &nbsp; &nbsp; while not eof do<br>&nbsp; &nbsp; &nbsp; begin<br>&nbsp; &nbsp; &nbsp; &nbsp; ComboBox2.Items.Add(查询的数据);<br>&nbsp; &nbsp; &nbsp; end;<br>&nbsp; end;<br>end;

来晚了

呵呵 还不一定他能看懂呢

我来对上面代码进行下补充：<br>用ComboBox的onchange事件<br>procedure TForm1.ComboBox1Change(Sender: TObject);<br>begin<br>&nbsp; with adq do<br>&nbsp; begin<br>&nbsp; &nbsp; Close;<br>&nbsp; &nbsp; sql.clear;<br>&nbsp; &nbsp; sql.add('查询语句');<br>&nbsp; &nbsp; Open;<br>&nbsp; &nbsp; if isempty then<br>&nbsp; &nbsp; &nbsp; showmessage('该数据为空')<br>&nbsp; &nbsp; else<br>&nbsp; &nbsp; //--add by lngdtommy　<br>&nbsp; &nbsp; begin<br>&nbsp; &nbsp; &nbsp; ComboBox2.Items.Clear; //这需要将ComboBox2清空。。。 <br>&nbsp; &nbsp; //--end add...<br>&nbsp; &nbsp; &nbsp; while not eof do<br>&nbsp; &nbsp; &nbsp; begin<br>&nbsp; &nbsp; &nbsp; &nbsp; ComboBox2.Items.Add(查询的数据);<br>&nbsp; &nbsp; &nbsp; &nbsp; Next; &nbsp;//这也需要，否则死循环。。。<br>&nbsp; &nbsp; &nbsp; end;<br>&nbsp; &nbsp; //--add by lngdtommy<br>&nbsp; &nbsp; end;<br>&nbsp; &nbsp; //--end add....<br>&nbsp; end;<br>end;

我说呢，原来没写next