p; return -1;
for( int i = start ; i <= len - substr.Len() ; i++ )
{
  if( str[i] == substr.GetAt(0) )
  {
   bool flag = true;
   int j;
   for( j = 0 ; flag && j < substr.Len() && (i + j < len) ; j++ )
   {
    if( str[i+j] != substr.GetAt(j) )
     flag = false;
   }
   if( j >= substr.Len() && flag )
   {
    return i;
   }
  }
}
return -1;
}
//
//判断字符串substr是否字符串的子串
bool string::InStr( string substr )
{
if( FindFirstSub( substr ) < 0 )
  return false;
else
  return true;
}
//
//去前导、后导空格
string string::Trim( int part = TRIM_BOTH )
{
string s = *this;
char *temp = new char(Len()+1);
int i , j , k;

if( part == TRIM_LEFT || part == TRIM_BOTH )
{
  j = 0;
  while( s.GetAt(j) == '''' '''' && j < s.Len() )
   j++;
  k = s.Len();
  i = 0;
  while( j <= k )
   temp[i++] = s.GetAt(j++);
  s = (string)temp;
}

if( part == TRIM_RIGHT || part == TRIM_BOTH )
{
  j = s.Len() - 1;
  while( s.GetAt(j) == '''' '''' )
   j--;
  for( i = 0 ; i <= j ; i++ )
   temp[i] = s.GetAt(i);
  temp[i] = 0;
  s = (string)temp;
}
return s;
}
//
//字符串左部长度为sublen的子串
string string::Left( int sublen )
{
if( sublen > len )
  sublen = len;
char *substr = new char(sublen+1);
for( int i = 0 ; i < sublen ; i++ )
  substr[i] = str[i];
substr[sublen] = 0;
string sub(substr);
return sub;
}
//
//字符串右部长度为sublen的子串
string string::Right( int sublen )
{
if( sublen > len )
  sublen = len;
char *substr = new char(sublen+1);
for( int i = 0 ; i < sublen ; i++ )
  substr[i] = str[len-sublen+i];
substr[sublen] = 0;
string sub(substr);
return sub;
}
//
//字符串中间从start开始长度为sublen的子串
string string::Mid( int start , int sublen )
{
if( start > len || sublen <= 0 )
{
  string sub("");
  return sub;
}

if( start + sublen > len )
  sublen = len - start;

char *substr = new char(sublen+1);
for( int i = 0 ; i < sublen ; i++ )
  substr[i] = str[start+i];
substr[sublen] = 0;
string sub(substr);
return sub;
}
//
//将字符串中所有形如strNeedReplaced的子串替换为strReplace
void string::Replace( string strNeedReplaced , string strReplace )
{
string temp;
int start = 0;
int index = FindFirstSub( strNeedReplaced , start );
while( index >= 0 )
{
  temp = temp + Mid( start , index - start ) + strReplace;

  start = index + strNeedReplaced.Len();
  index = FindFirstSub( strNeedReplaced , start );
}

temp = temp + Right( len - start );
len = temp.Len();
str = new char(len+1);
strcpy( str , (char*)temp );
}
// string类结束
/////////////////////