C#小数点格式化
1.ToString()方法
double d=12345678.2334; Console.WriteLine(d.ToString("F2")); //1234.23 Console.WriteLine(d.ToString("###,###.00")); //12,345,678.23
2.Math.Round()方法
Math.Round(3.44, 1); //Returns 3.4. Math.Round(3.45, 1); //Returns 3.4. Math.Round(3.46, 1); //Returns 3.5. Math.Round(3.445, 1); //Returns 3.4. Math.Round(3.455, 1); //Returns 3.5. Math.Round(3.465, 1); //Returns 3.5. Math.Round(3.450, 1); //Returns 3.4.(补0是无效的) Math.Round(3.4452, 2); //Returns 3.45. Math.Round(3.4552, 2); //Returns 3.46. Math.Round(3.4652, 2); //Returns 3.47.
"四舍六入五考虑,五后非零就进一,五后皆零看奇偶,五前为偶应舍 去,五前为奇要进一"
短一点的口诀叫“四舍、六入、五凑偶”
3.double.Parse()方法
double d=1.12345; d=double.Parse(d.ToString("0.00")); //1.12
4.String.Format()方法
string str1 = String.Format("{0:N1}",56789); //result: 56,789.0 string str2 = String.Format("{0:N2}",56789); //result: 56,789.00 string str3 = String.Format("{0:N3}",56789); //result: 56,789.000 string str8 = String.Format("{0:F1}",56789); //result: 56789.0 string str9 = String.Format("{0:F2}",56789); //result: 56789.00 string str11 =(56789 / 100.0).ToString("#.##"); //result: 567.89 string str12 =(56789 / 100).ToString("#.##"); //result: 567
原文链接:http://qubernet.blog.163.com/blog/static/17794728420121102123822/