学用 ASP.Net 之 System.Random 类

成员:

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Next();       //获取 0 .. int.MaxValue 的 int 随机数; 可指定范围
NextBytes();  //获取 0 .. 255 的随机数并填充字节数组
NextDouble(); //获取 0 .. 1 的 double 随机数

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构造函数:

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//不指定随机种子, 则默认有系统时钟生成种子
protected void Button1_Click(object sender, EventArgs e)
{
    Random r = new Random();
    int n1 = r.Next();
    int n2 = r.Next();

    TextBox1.Text = string.Concat(n1, "\n", n2);
}

//种子值相同时, 其随机序列也相同
protected void Button2_Click(object sender, EventArgs e)
{
    Random r1 = new Random(1);
    Random r2 = new Random(1);
    Random r3 = new Random(2);

    byte[] bs1 = new byte[10];
    byte[] bs2 = new byte[10];
    byte[] bs3 = new byte[10];

    r1.NextBytes(bs1);
    r2.NextBytes(bs2);
    r3.NextBytes(bs3);

    string s1 = string.Join(", ", bs1); //70, 208, 134, 130, 64, 151, 228, 163, 149, 207
    string s2 = string.Join(", ", bs2); //70, 208, 134, 130, 64, 151, 228, 163, 149, 207
    string s3 = string.Join(", ", bs3); //113, 147, 198, 149, 36, 185, 227, 111, 124, 56

    TextBox1.Text = string.Concat(s1, "\n", s2, "\n", s3);
}

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练习:

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protected void Button1_Click(object sender, EventArgs e)
{
    Random r = new Random(0);

    int n1 = r.Next();           //1559595546
    int n2 = r.Next(10);         //8
    int n3 = r.Next(1000, 2000); //1768

    TextBox1.Text = string.Concat(n1, "\n", n2, "\n", n3);
}

protected void Button2_Click(object sender, EventArgs e)
{
    Random r = new Random(0);

    double f;
    string str = "";
    for (int i = 0; i < 10; i++)
    {
        f = r.NextDouble();
        str += f.ToString("0.00 "); //0.73 0.82 0.77 0.56 0.21 0.56 0.91 0.44 0.98 0.27
    }
    TextBox1.Text = str;
}

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