常用数字处理小技巧

说明: 平时编程中总会遇到数字处理问题, 这里将自己平时总结的一些数字处理小技巧结合MSDN上相关的介绍, 列举一些常用的数字处理技术.

 原理非常简单, 不再细说, 只图自己和大家引用或参考时方便.

1.对计算结果四舍五入(d:数,i小数位数)

 效果: 233.8763

 -->  233.88

        //d: 表示四舍五入的数字;  i: 保留的小数位数 
        public static double Round(double d, int i)
        {
            if (d >= 0)
            {
                d += 5 * Math.Pow(10, -(i + 1));
            }
            else
            {
                d += -5 * Math.Pow(10, -(i + 1));
            }
            string str = d.ToString();
            string[] strs = str.Split('.');
            int idot = str.IndexOf('.');
            string prestr = strs[0];
            string poststr = strs[1];
            if (poststr.Length > i)
            {
                poststr = str.Substring(idot + 1, i);//截取需要位数
            }
            if (poststr.Length <= 2)
            {
                poststr = poststr + "0";
            }
            string strd = prestr + "." + poststr;
            d = Double.Parse(strd);//将字符串转换为双精度实数 
            return d;
        }

2.将商品金额小写转换成大写

 效果: 1234566789

    -->壹拾贰亿叁仟肆佰伍拾陆万陆仟柒佰捌拾玖元

        private void Convert_Click(object sender, EventArgs e)
        {
            String[] Scale = { "分", "角", "元", "拾", "佰", "仟", "万", "拾", "佰", "仟", "亿", "拾", "佰", "仟", "兆", "拾", "佰", "仟" };
            String[] Base = { "零", "壹", "贰", "叁", "肆", "伍", "陆", "柒", "捌", "玖" };
            String Temp = textBox1.Text.ToString();
            String Info = null;
            int index = Temp.IndexOf(".", 0, Temp.Length);//判断是否有小数点
            if (index != -1)
            {
                Temp = Temp.Remove(Temp.IndexOf("."), 1);
                for (int i = Temp.Length; i > 0; i--)
                {
                    int Data = Convert.ToInt16(Temp[Temp.Length - i]);
                    Info += Base[Data - 48];
                    Info += Scale[i - 1];
                }
            }
            else
            {
                for (int i = Temp.Length; i > 0; i--)
                {

                    int Data = Convert.ToInt16(Temp[Temp.Length - i]);
                    Info += Base[Data - 48];
                    Info += Scale[i + 1];
                }

            }

            textBox2.Text = Info;
        }

3.设置货币值中使用的小数位数

 

       System.Globalization.NumberFormatInfo GN = new         System.Globalization.CultureInfo("zh-CN", false).NumberFormat;
        Int64 myInt = 12345;
        private void SetLL_Click(object sender, EventArgs e)
        {
            GN.CurrencyDecimalDigits = 4;
            MessageBox.Show(myInt.ToString("C", GN), "保留四位小数");
        }

4.自定义货币值中的小数点

System.Globalization.NumberFormatInfo GN = new System.Globalization.CultureInfo("zh-CN", false).NumberFormat;
        Int64 myInt = 123456789;
        private void button1_Click(object sender, EventArgs e)
        {
            GN.CurrencyDecimalSeparator = "$";
            MessageBox.Show("定义前:" + myInt.ToString("C") + "\n" + "定义后:" + myInt.ToString("C", GN), "自定义小数点为$符");
        }

5.自定义货币值中小数点左边每一组的位数 

System.Globalization.NumberFormatInfo CN = new System.Globalization.CultureInfo("en-US", false).NumberFormat;
            Int64 myInt = 123456789012345;
            int[] mySizes1 = { 2, 3, 1 };
            int[] mySizes2 = { 2, 3, 2 };
            CN.CurrencyGroupSizes = mySizes1;
            MessageBox.Show("定义前：" + myInt.ToString("C") + "\n" + "定义后：" + myInt.ToString("C", CN), "{ 2, 3, 1 }格式");
            CN.CurrencyGroupSizes = mySizes2;
            MessageBox.Show("定义前：" + myInt.ToString("C") + "\n" + "定义后：" + myInt.ToString("C", CN), "{ 2, 3, 2 }格式");

6.自定义货币值中小数点左边数字分组字符

 System.Globalization.NumberFormatInfo GN = new System.Globalization.CultureInfo("en-US", false).NumberFormat;
            Int64 myInt = 123456789;
            GN.CurrencyGroupSeparator = "、";
            MessageBox.Show("定义前： " + myInt.ToString("C") + "\n" + "定义后： " + myInt.ToString("C", GN), "分组字符用、号");

7.自定义百分比符号

效果: 默认符号： 10,257,865.84%
自定义符号&： 10,257,865.84&
自定义符号*： 10,257,865.84*
自定义符号#： 10,257,865.84#

 System.Globalization.NumberFormatInfo GN = new System.Globalization.CultureInfo("zh-CN", false).NumberFormat;
            double intPrecnt = 102578.6584;
            string strPrecnt = null;
            GN.PercentSymbol = "%";
            strPrecnt += "默认符号： " + intPrecnt.ToString("p", GN);
            GN.PercentSymbol = "&";
            strPrecnt += "\n自定义符号&： " + intPrecnt.ToString("p", GN);
            GN.PercentSymbol = "*";
            strPrecnt += "\n自定义符号*： " + intPrecnt.ToString("p", GN);
            GN.PercentSymbol = "#";
            strPrecnt += "\n自定义符号#： " + intPrecnt.ToString("p", GN);
            MessageBox.Show(strPrecnt, "设置效果", MessageBoxButtons.OK, MessageBoxIcon.Information);

8.自定义数字小数点右边的保留位数

效果: 原始数字: 4458524.2568412547

默认小数位数：4,458,524.26
保留三位小数：4,458,524.257
保留五位小数：4,458,524.25684
保留五位小数：4,458,524.2568413

System.Globalization.NumberFormatInfo GN = new System.Globalization.CultureInfo("zh-CN", false).NumberFormat;
            double intNumber = 4458524.2568412547;
            string strNumber = "";
            strNumber += "默认小数位数：" + intNumber.ToString("N");
            GN.NumberDecimalDigits = 3;
            strNumber += "\n保留三位小数：" + intNumber.ToString("N", GN);
            GN.NumberDecimalDigits = 5;
            strNumber += "\n保留五位小数：" + intNumber.ToString("N", GN);
            GN.NumberDecimalDigits = 7;
            strNumber += "\n保留五位小数：" + intNumber.ToString("N", GN);
            MessageBox.Show(strNumber, "设置效果", MessageBoxButtons.OK, MessageBoxIcon.Information);

9.自定义数字小数点左边分组位数(从小数点开始向左)

 效果: 默认格式：711,413,414,517.12

{ 1, 3, 4 }格式：7114,1341,451,7.12
{ 2, 3, 0 }格式：7114134,145,17.12
{ 2, 6, 2 }格式：71,14,134145,17.12

System.Globalization.NumberFormatInfo GN = new System.Globalization.CultureInfo("zh-CN", false).NumberFormat;
            double intNumber = 711413414517.12;
            string strNumber = null;
            strNumber += "默认格式：" + intNumber.ToString("N", GN);
            int[] MySizes1 = { 1, 3, 4 };
            GN.NumberGroupSizes = MySizes1;
            strNumber += "\n{ 1, 3, 4 }格式：" + intNumber.ToString("N", GN);
            int[] MySizes2 = { 2, 3, 0 };
            GN.NumberGroupSizes = MySizes2;
            strNumber += "\n{ 2, 3, 0 }格式：" + intNumber.ToString("N", GN);
            int[] MySizes3 = { 2, 6, 2 };
            GN.NumberGroupSizes = MySizes3;
            strNumber += "\n{ 2, 6, 2 }格式：" + intNumber.ToString("N", GN);
            MessageBox.Show(strNumber, "设置效果", MessageBoxButtons.OK, MessageBoxIcon.Information);

10.格式化输入数据为货币格式

效果: 输入: 12345

        输出: ￥12 345.00

            try
            {
                System.Globalization.NumberFormatInfo nfi = new System.Globalization.CultureInfo("zh-CN", false).NumberFormat;
                nfi.CurrencyGroupSeparator = " ";
                textBox2.Text = Convert.ToDouble(textBox1.Text).ToString("c", nfi);
            }
            catch (Exception ee)
            {
                MessageBox.Show(ee.Message);
            }