学用 ASP.Net 之 System.Collections.BitArray 类

常用成员:

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/* 属性 */

Count    //只读

Length   //同 Count, 但可读写



/* 方法 */

And()    //与

Get()    //取值

Not()    //取反

Or()     //或

Set()    //赋值

SetAll() //全部设定为指定值

Xor()    //异或

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练习:

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//(items)[]、Get()、Set()

protected void Button1_Click(object sender, EventArgs e)

{

    BitArray bits = new BitArray(new bool[3] { true, false, true });



    bool b1 = bits[0];       //True

    bool b2 = bits[1];       //False

    //bool b1 = bits.Get(0);

    //bool b2 = bits.Get(1);

    

    bits[0] = false;

    bits[1] = true;

    //bits.Set(0, false);

    //bits.Set(1, true);



    bool b11 = bits[0]; //False

    bool b22 = bits[1]; //True



    TextBox1.Text = string.Concat(b1, "\n", b2, "\n", b11, "\n", b22);

} 



//SetAll() 及遍历

protected void Button2_Click(object sender, EventArgs e)

{

    BitArray bits = new BitArray(5);



    string str1 = "";

    foreach (bool b in bits)

    {

        str1 += b.ToString() + " "; //False False False False False 

    }



    bits.SetAll(true);

    string str2 = "";

    foreach (bool b in bits)

    {

        str2 += b.ToString() + " "; //True True True True True 

    }

    TextBox1.Text = str1 + "\n" + str2;

}



//Count、Length

protected void Button3_Click(object sender, EventArgs e)

{

    BitArray bits = new BitArray(5);



    int n1 = bits.Count; //5



    bits.Length = 3;

    int n2 = bits.Count; //3



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

}



//Not()

protected void Button4_Click(object sender, EventArgs e)

{

    BitArray bits = new BitArray(new bool[4] { true, false, true, false });

    bits.Not();                             // False,True,  False,True

    TextBox1.Text = string.Format("{0},{1},{2},{3}", bits[0], bits[1], bits[2], bits[3]);

}



//And()

protected void Button5_Click(object sender, EventArgs e)

{

    BitArray bits1 = new BitArray(new bool[4] { true, false, true,  false });

    BitArray bits2 = new BitArray(new bool[4] { true, true,  false, false });



    bits1.And(bits2);                        // True, False, False, False

    TextBox1.Text = string.Format("{0},{1},{2},{3}", bits1[0], bits1[1], bits1[2], bits1[3]);

}



//Or()

protected void Button6_Click(object sender, EventArgs e)

{

    BitArray bits1 = new BitArray(new bool[4] { true, false, true,  false });

    BitArray bits2 = new BitArray(new bool[4] { true, true,  false, false });



    bits1.Or(bits2);                        // True,  True,  True,   False

    TextBox1.Text = string.Format("{0},{1},{2},{3}", bits1[0], bits1[1], bits1[2], bits1[3]);

}



//Xor()

protected void Button7_Click(object sender, EventArgs e)

{

    BitArray bits1 = new BitArray(new bool[4] { true, false, true,  false });

    BitArray bits2 = new BitArray(new bool[4] { true, true,  false, false });



    bits1.Xor(bits2);                        // False,True,  True,  False

    TextBox1.Text = string.Format("{0},{1},{2},{3}", bits1[0], bits1[1], bits1[2], bits1[3]);

}



//其它建立方法

protected void Button8_Click(object sender, EventArgs e)

{

    //对象包含 3 个 true

    BitArray bits1 = new BitArray(3, true);



    //以 byte[] 为参数时, 将把其每个 byte 的 8 个位分别映射为一个元素

    BitArray bits2 = new BitArray(new byte[3] { byte.MaxValue, byte.MinValue, byte.MaxValue });



    //以 int[] 为参数时, 将把其每个 int 的 32 个位分别映射为一个元素

    BitArray bits3 = new BitArray(new int[3] { int.MaxValue, int.MinValue, int.MaxValue });



    int n1 = bits1.Length; //3

    int n2 = bits2.Length; //24

    int n3 = bits3.Length; //96



    string s1, s2, s3;

    s1 = s2 = s3 = "";



    foreach (bool b in bits1) { s1 = string.Concat(s1, Convert.ToByte(b)); } //111



    foreach (bool b in bits2) { s2 = string.Concat(s2, Convert.ToByte(b)); } //11111111

                                                                             //00000000

                                                                             //11111111



    foreach (bool b in bits3) { s3 = string.Concat(s3, Convert.ToByte(b)); } //11111111111111111111111111111110

                                                                             //00000000000000000000000000000001

                                                                             //11111111111111111111111111111110

    TextBox1.Text = string.Concat(n1, "\n", n2, "\n", n3, "\n", s1, "\n", s2, "\n", s3);

}

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