再问：如何判断variant类型的值是否为空？(100分)

代码如下：<br>with DataSet do<br>&nbsp; if VarIsEmpty(DieldByName('iCode').Value) <br>&nbsp; &nbsp; or VarIsEmpty(DieldByName('cText').Value) then<br>&nbsp; begin<br>&nbsp; &nbsp; ShowMessage('请输入代码');<br>&nbsp; &nbsp; abort;<br>&nbsp; end<br>&nbsp; else<br>&nbsp; &nbsp; ShowMessage(inttostr(FieldByName('iCode').Value)+' &nbsp;'<br>&nbsp; &nbsp; &nbsp; +FieldByName('iCode').Value;<br>为什么当cText没有内容时，两个ShowMessage都不执行，而iCode没有内容时会出错：Could not convert variant of type (Null) into<br>type (Integer)?

VarIsNull

DieldByName('iCode').isNull 也可以判断

with DataSet do<br>&nbsp; if VarIsEmpty(FieldByName('iCode').Value) <br>&nbsp; &nbsp; or VarIsEmpty(FieldByName('cText').Value) <br>&nbsp; &nbsp; or (trim(FieldByName('cText').AsString)='') then<br>&nbsp; begin<br>&nbsp; &nbsp; ShowMessage('请输入代码');<br>&nbsp; &nbsp; abort;<br>&nbsp; end<br>&nbsp; else<br>&nbsp; &nbsp; ShowMessage(inttostr(FieldByName('iCode').Value)+' &nbsp;'<br>&nbsp; &nbsp; &nbsp; +FieldByName('cText').AsString;

本问题属重复问题，不好意思