iOS混排计算中英文个数，中午算一个字符，英文和符号算半个字符
-(int)convertToInt:(NSString*)strtemp { int strlength = 0; char* p = (char*)[strtemp cStringUsingEncoding:NSUnicodeStringEncoding]; for (int i=0 ; i<[strtemp lengthOfBytesUsingEncoding:NSUnicodeStringEncoding] ;i++) { if (*p) { p++; strlength++; } else { p++; } } return (strlength+1)/2; }