数据类型转换byteushotint64(long)

/**
* 64 00 64 00
77 BE 9F 1A 2F DD 5E 40
equipnum = 6553700
equipnum = 6553700
equipnum = 6553700
equipnum = 6553700
*
* */
private void button4_Click(object sender, EventArgs e)
{
//int i = 123;
int i = 6553700;
byte[] intBuff = BitConverter.GetBytes(i); // 将 int 转换成字节数组
foreach (byte b in intBuff)
{
richTextBox1.AppendText(string.Format("{0} ", b.ToString("X2")));
}
i = BitConverter.ToInt32(intBuff, 0); // 从字节数组转换成 int
richTextBox1.AppendText(" ");

        double x = 123.456;
        byte[] doubleBuff = BitConverter.GetBytes(x);  // 将 double 转换成字节数组
        foreach (byte b in doubleBuff)
        {
            richTextBox1.AppendText(string.Format("{0} ", b.ToString("X2")));
        }
        x = BitConverter.ToDouble(doubleBuff, 0);       // 从字节数组转换成 double

        // ushort数组 转 long(int64)
        // 1、移位
        ushort[] arr = new ushort[] { 100, 100, 0, 0 };
        Int64 equipNum = 0;
        for (int m = 0; m < 4; m++)
        {
            equipNum = equipNum | (arr[m] << m * 16);
        }
        richTextBox1.AppendText(string.Format("equipnum = {0}
", equipNum));

        // 2、使用BitConverter，先转为字节，在转为long
        byte[] by = new byte[8];
        for (int m = 0; m < 4; m++)
        {
            byte[] b = BitConverter.GetBytes(arr[m]);
            by[2*m] = b[0];
            by[2*m+1] = b[1];
        }
        equipNum = BitConverter.ToInt64(by, 0);
        richTextBox1.AppendText(string.Format("equipnum = {0}
", equipNum));

        byte[] bys = new byte[8];
        for (int m = 0; m < 4; m++)
        {
            byte[] b = BitConverter.GetBytes(arr[m]);
            Array.Copy(b, 0, bys, 2 * m, 2);
        }
        equipNum = BitConverter.ToInt64(bys, 0);
        richTextBox1.AppendText(string.Format("equipnum = {0}
", equipNum));

        byte[] bya = new byte[8];
        int k = 0;
        foreach (var a in arr)
        {
            byte[] b = BitConverter.GetBytes(a);
            Array.Copy(b, 0, bya, 2 * k, 2);
            k += 1;
        }
        equipNum = BitConverter.ToInt64(bya, 0);
        richTextBox1.AppendText(string.Format("equipnum = {0}
", equipNum));
    }