说明: { if (flag < 0) return; if (flag == 0) sum = sum + Convert.ToDouble(textBox.Text); if(flag==1) sum = sum - Convert.ToDouble(textBox.Text); if(flag==2) sum = sum * Convert.ToDouble(textBox.Text); if(flag==3) sum = sum / Convert.ToDouble(textBox.Te <wg610> 上传 | 大小:60kb