/// <summary>
/// 将7-Bit编码字节数换算成UCS2编码字符数
/// </summary>
/// <param name="source">字符串</param>
/// <param name="index">起始索引号</param>
/// <param name="septets">要换算的7-Bit编码字节数</param>
/// <returns>UCS2编码字符数</returns>
private static Int32 SeptetsToChars(String source, Int32 index, Int32 septets)
{
if (String.IsNullOrEmpty(source))
{
return(0);
}
Int32 Count = 0;
Int32 i = index;
for (; i < source.Length; i++)
{
UInt16 Code = Convert.ToUInt16(source[i]);
if (UCS2ToBIT7.ContainsKey(Code) && UCS2ToBIT7[Code] > 0xFF)
{
Count++;
}
if (++Count >= septets)
{
if (Count == septets)
{
i++;
}
break;
}
}
return(i - index);
}
/// <summary>
/// 判断字符串是否在GSM缺省字符集内
/// </summary>
/// <param name="source">要评估的字符串</param>
/// <returns>
/// true：在GSM缺省字符集内，可以使用7-Bit编码
/// false：不在GSM缺省字符集内，只能使用UCS2编码
/// </returns>
private static Boolean isGSMString(String source)
{
if (String.IsNullOrEmpty(source))
{
return(true);
}
foreach (Char Letter in source)
{
UInt16 Code = Convert.ToUInt16(Letter);
if (!(isBIT7Same(Code) || UCS2ToBIT7.ContainsKey(Code)))
{
return(false);
}
}
return(true);
}
/// <summary>
/// 将UCS2编码字符串转换成7-Bit编码字节 序列
/// </summary>
/// <param name="UDC">用户数据内容</param>
/// <param name="Septets">7-Bit编码字符数</param>
/// <returns>7-Bit编码字节序列</returns>
private static Byte[] BIT7Encoding(String UDC, out Int32 Septets)
{
Byte[] Bit7Array = new Byte[UDC.Length << 1];
Septets = 0;
foreach (Char Letter in UDC)
{
UInt16 Code = Convert.ToUInt16(Letter);
if (isBIT7Same(Code))
{ // 编码不变
Bit7Array[Septets++] = Convert.ToByte(Code);
}
else
{
if (UCS2ToBIT7.ContainsKey(Code))
{
UInt16 Transcode = UCS2ToBIT7[Code]; // 转换码
if (Transcode > 0xFF)
{ // 转义序列
Bit7Array[Septets++] = Convert.ToByte(Transcode >> 8);
Bit7Array[Septets++] = Convert.ToByte(Transcode & 0xFF);
}
else
{
Bit7Array[Septets++] = Convert.ToByte(Transcode);
}
}
else
{ // 未知字符
Bit7Array[Septets++] = Convert.ToByte('?');
}
}
}
// 重新调整大小
Array.Resize(ref Bit7Array, Septets);
return(Bit7Array);
}
/// <summary>
/// 计算字符串需要的7-Bit编码字节数
/// </summary>
/// <param name="source">字符串</param>
/// <returns>7-Bit编码字节数</returns>
private static Int32 SeptetsLength(String source)
{
if (String.IsNullOrEmpty(source))
{
return(0);
}
Int32 Length = source.Length;
foreach (Char Letter in source)
{
UInt16 Code = Convert.ToUInt16(Letter);
if (UCS2ToBIT7.ContainsKey(Code))
{
if (UCS2ToBIT7[Code] > 0xFF)
{
Length++;
}
}
}
return(Length);
}