字节 汉字判断

• XE7

TMbcsByteType : unsigned char { mbSingleByte, mbLeadByte, mbTrailByte };

TMbcsByteType __fastcall ByteType _DEPRECATED_ATTRIBUTE1("Moved to the AnsiStrings unit") (const System::AnsiString S, int Index)/* overload */;
TMbcsByteType __fastcall ByteType(const System::UnicodeString S, int Index)/* overload */;

System.UnicodeString.IsLeadSurrogate

bool IsLeadSurrogate(int index)

Tests whether the element is a lead surrogate.

IsLeadSurrogate returns true if the indexed element is a lead surrogate and false otherwise. Note that index is an element index into the string, not a character or byte index. 

System.UnicodeString.IsTrailSurrogate

bool         IsTrailSurrogate(int index)

Tests whether the element is a trail surrogate.

IsTrailSurrogate returns True if the indexed element is a trail surrogate and False, otherwise. Note that index is an element index into the string, not a character or byte index. 

• c6

IsLeadByte

IsTrailByte

Returns true if the specified byte is a lead byte.

bool __fastcall IsLeadByte(int index) const;

Description

IsLeadByte returns true if the byte indicated by index (counting from 0) is the lead byte in a multi-byte character. If the byte is a trailing byte, or not part of a multi-byte character, IsLeadByte returns false.

Returns true if the specified byte is of type mbTrailByte.

bool __fastcall IsTrailByte(int index) const;

Description

IsTrailByte returns true if the byte indicated by index (counting from 0) is the trailing byte in a multi-byte character. If the byte is a lead byte, or not part of a multi-byte character, IsTrailByte returns false.

System.SysUtils.TMbcsByteType

TMbcsByteType = (mbSingleByte, mbLeadByte, mbTrailByte);

TMbcsByteType represents the use of a single byte in a string that uses a multi-byte character set (MBCS).

TMbcsByteType represents the possible return values of the ByteType and StrByteType functions. Possible values are as follows. 

mbSingleByte	The char is used to represent an entire character in the string. The value of Char cannot be included in the LeadBytes set.
mbLeadByte	The char is used to represent the first byte of a multi-byte character. The value of Char must be included in the LeadBytes set.
mbTrailByte	The char is used to represent one of the trailing bytes in a multi-byte character. There are no a priori restrictions on the value of char.

判断是否数字数值

IsDigit

判断是否