学步园

z，jz : 进制，只取2,8,10，16

 1.十进制-多进制     

（无小数)      

 string str= mResult.ToString();
     TextBoxResult.Text= Convert.ToString(int.Parse(str),z);

(有小数）

//进制转换。十进制-多进制字符串
    public string change_d(double num,int jz)
    {
        char[] y = new Char[30];
        char[] y0 = new Char[20];
        int numb1 = (int)num;//num的整数位
        double numb2 = num - (double)numb1;//num的小数位
        int i = 0;
        for (i = 0; numb1 != 0; i++)
        {
            if ((numb1 % jz) <= 9 && (numb1 % jz) >= 0)
                y0[i] = Convert.ToChar((numb1 % jz) + '0');
            else
                y0[i] = Convert.ToChar((numb1 % jz) + 'a' - 10);
            numb1 /= jz;
        }
        for (int u = 0; u < i; u++)
        {
            y[u] = y0[i - u - 1];
        }
        if (numb2 > 0.0000001)
        {
            y[i] = '.';

            for (int j = i + 1; numb2 != 0 && j - i <= 10; j++)
            {

                if ((numb2 * jz) <= 9 && (numb2 * jz) >= 0)
                    y[j] = Convert.ToChar((int)(numb2 * jz) + '0');
                else
                    y[j] = Convert.ToChar((int)(numb2 * jz) + 'a' - 10);
                double z = (int)(numb2 * jz);
                numb2 = numb2 * jz - z;
            }
        }
        string str = new string(y);
        return str;
    }

 2.多进制-十进制    (允许小数）

public double change_s(int jz)
    {
        double dot = 0;
        double y = 0;
        char[] x = TextBoxResult.Text.ToCharArray();
        int w = 0;
        int m = 0;
        for (int i = TextBoxResult.Text.Length - 1; i >= 0; i--)
        {

            if (x[i] != '.')
            {
                m = 1;
                for (int j = 0; j < w; j++)
                {
                    m *= jz;
                }
                if (x[i] - '0' <= 9) y += m * (x[i] - '0');
                else { y += m * (x[i] - '0' - 39); };
                w++;
                m *= jz;

            }//end of  --if (x[i] != '.')
            else
            {
                dot = m;
            }
        }//end of ---for
        if (dot != 0) y /= dot;
        return y;
    }

不足：

精度有问题，并且代码还不够精炼规范。

希望有更好的算法