直接用数值表示string.Format("F",YourFloatNum)详细参考:
ms-help://MS.VSCC/MS.MSDNVS.2052/cpguide/html/cpconstandardnumericformatstrings.htm
ms-help://MS.VSCC/MS.MSDNVS.2052/cpguide/html/cpconstandardnumericformatstrings.htm
MessageBox.Show(a.ToString("F")); decimal a = 1112222333333333333.55567357467654M;
MessageBox.Show(a.ToString("F"));