从打开窗口里面选择路径,打开了一个数据库,在打开一个就成这样了,ADOcon,ADOquery,ADOTable全放到DataMoudel里了 procedure TMainForm.FileOpen1Execute(Sender: TObject); begin if(self.MDIChildCount<3) then begin if OpenDialog.Execute then begin ADM.ADODataModule.ADOCon.ConnectionString:='Provider=Microsoft.Jet.OLEDB.4.0;User ID=Admin;Data Source='+self.OpenDialog.FileName+';'; try if(ADODataModule.Connected) then ADODataModule.ADOCon.Close; CreateMDIChild(OpenDialog.FileName); Except ADODataModule.ADOCon.Close end; end; end else Application.MessageBox('33333,'!',0); end;