private void Freg_Load(object sender, EventArgs e)
{
    this.label2.Visible = false;
    this.Text1.Text = this.getCpu() + this.GetDiskVolumeSerialNumber();
    this.Text1.Text = this.Text1.Text.Substring(2, 7) + this.Text1.Text.Substring(15, 8);
    string text = "";
    text = this.Text1.Text;
    string[] strArray = new string[0x19];
    string str2 = "";
    for (int i = 5; i < 14; i++)
    {
        strArray[i] = text.Substring(i, 1);
        if (strArray[i] == "0")
        {
            strArray[i] = "0";
        }
        else if (strArray[i] == "1")
        {
            strArray[i] = "1";
        }
        else if (strArray[i] == "2")
        {
            strArray[i] = "2";
        }
        else if (strArray[i] == "3")
        {
            strArray[i] = "3";
        }
        else if (strArray[i] == "4")
        {
            strArray[i] = "4";
        }
        else if (strArray[i] == "5")
        {
            strArray[i] = "5";
        }
        else if (strArray[i] == "6")
        {
            strArray[i] = "6";
        }
        else if (strArray[i] == "7")
        {
            strArray[i] = "7";
        }
        else if (strArray[i] == "8")
        {
            strArray[i] = "8";
        }
        else if (strArray[i] == "9")
        {
            strArray[i] = "9";
        }
        else if (strArray[i] == "A")
        {
            strArray[i] = "0";
        }
        else if (strArray[i] == "B")
        {
            strArray[i] = "1";
        }
        else if (strArray[i] == "C")
        {
            strArray[i] = "2";
        }
        else if (strArray[i] == "D")
        {
            strArray[i] = "3";
        }
        else if (strArray[i] == "E")
        {
            strArray[i] = "4";
        }
        else if (strArray[i] == "F")
        {
            strArray[i] = "5";
        }
        else if (strArray[i] == "G")
        {
            strArray[i] = "6";
        }
        else if (strArray[i] == "H")
        {
            strArray[i] = "7";
        }
        else if (strArray[i] == "I")
        {
            strArray[i] = "8";
        }
        else
        {
            strArray[i] = "9";
        }
        str2 = str2 + strArray[i];
    }
    double num2 = Convert.ToDouble(str2) * 13567.0;
    this.textBox1.Text = Convert.ToString(num2).Substring(4, 8);
    this.textBox1.Visible = false;
}

希望得到讲解。

这个运算我有点糊涂了，希望高人指点下。

谢谢大神解答。。。虽然不够详细让我理解，不过也挺好了。。。呵呵！！我还是c#知识太薄弱不懂哦。