关于DBGRID的问题

Question

判断字段的类型,如为INT型,则判断是否小于0

Answer 1

try
  if DBGrid1.DataSource.DataSet.FieldByName('').asFloat<0 then
    showmessage('>0');
except
    showmessage('不是数字');
end;

Answer 2

try
  if DBGrid1.DataSource.DataSet.FieldByName('').asFloat<0 then
    showmessage('<0');//上面这儿写错了！sorry!
except
    showmessage('不是数字');
end; 
 

Answer 3

IF VarIsNumeric(dbgrid1.SelectedField.Value) Then
IF dbgrid1.SelectedField.Value>0 Then

Answer 4

就写在DBGrid的onkeypress事件中即可。