转：C# 小数位数保留的方法集锦

System.Globalization.NumberFormatInfo provider = new System.Globalization.NumberFormatInfo();
provider.NumberDecimalDigits =intDecLength; //要设定的小数位数
double strCashAmt=Convert.ToDouble(this.txtCashAmt.Text); //先把控件內的值转成double
this.txtCashAmt.Text = strCashAmt.ToString("N",provider); //再利用ToString函数格式化小数位数

decimal d= decimal.Round(decimal.Parse("0.55555"),2);

Math.Round(0.55555,2)

double dbdata = 0.55555;
string str1 = dbdata.ToString("f2");//fN 保留N位，四舍五入

string result = String.Format("{0:N2}", 0.55555);//2位
string result = String.Format("{0:N3}", 0.55555);//3位

double s=0.55555;
result=s.ToString("#0.00");//点后面几个0就保留几位