/// <summary>
/// 重新构造二叉树
/// </summary>
/// <param name="strExpression">表达式</param>
public void ChangeExpression(string strExpression)
{
_Expression = strExpression;
_Tree = null;
_Position = 0;
_Identifiers = null;
_CurrentIdentifier = null;
_ParentIdentifier = null;
if (strExpression != string.Empty)
{
try
{
_ExpressionChars = new Char[strExpression.Length + 1];
strExpression.CopyTo(0, _ExpressionChars, 0, strExpression.Length);
_ExpressionChars[strExpression.Length] = '\0';
_Tree = DoExpression();
if (_ExpressionChars[_Position] != '\0')
{
throw ParsingException.NewParsingException(Parse_Error.peSyntaxError, _Position);
}
}
finally
{
_CurrentIdentifier = null;
_ParentIdentifier = null;
}
}
}
//私有方法
/// <summary>
/// 顺序输出标识符
/// </summary>
/// <param name="oID"></param>
/// <param name="strID"></param>
/// <param name="nPos"></param>
private void OutputID(Operation_IDs oID, string strID, int nPos)
{
if (OutputIdentifiers)
{
ParseIdentifier pi = new ParseIdentifier(oID, strID, nPos, _CurrentIdentifier);
if (_CurrentIdentifier == null)
{
if (_ParentIdentifier == null)
{
_Identifiers = pi;
}
else
{
_ParentIdentifier._SubIdentifier = pi;
}
}
else
{
_CurrentIdentifier._NextIdentifier = pi;
}
pi._ParentIdentifier = _ParentIdentifier;
_CurrentIdentifier = pi;
}
}
public ParseIdentifier(Operation_IDs oID, string strID, int nPos, ParseIdentifier prev)
{
_OperationID = oID;
_Identifier = strID;
_Position = nPos;
_PrevIdentifier = prev;
}
private void OutputIDToParentLevel()
{
if (_ParentIdentifier != null)
{
_CurrentIdentifier = _ParentIdentifier;
_ParentIdentifier = _ParentIdentifier._ParentIdentifier;
}
}
private void OutputIDToSubLevel()
{
_ParentIdentifier = _CurrentIdentifier;
_CurrentIdentifier = null;
}