protected override Expression VisitMethodCall(MethodCallExpression node)
{
if (node.Method.DeclaringType == typeof(WhereType))
{
if (node.Arguments.Count == 3 && node.Method.Name.Contains("Between"))
{
WhereExpression.Append("(");
Operator = WhereType.GetOperator(node.Method.Name);
Visit(node.Arguments[0]);
WhereExpression.AppendFormat(" {0} ", Operator);
Visit(node.Arguments[1]);
WhereExpression.AppendFormat(" AND ");
Visit(node.Arguments[2]);
WhereExpression.Append(")");
}
else if (node.Arguments.Count == 2)
{
WhereExpression.Append("(");
Visit(node.Arguments[0]);
Operator = WhereType.GetOperator(node.Method.Name);
WhereExpression.AppendFormat(" {0} ", Operator);
Visit(node.Arguments[1]);
WhereExpression.Append(")");
}
else if (node.Arguments.Count == 1)
{
WhereExpression.Append("(");
Visit(node.Arguments[0]);
Operator = WhereType.GetOperator(node.Method.Name);
WhereExpression.AppendFormat(" {0} ", Operator);
WhereExpression.Append(")");
}
}
else if (node.Method.GetCustomAttributes(typeof(FunctionAttribute), true).Length > 0)
{
WhereExpression.Append(new FunVisitor <T>().Build(Param, node, false));
SetName("", node.Method.Name);
}
else
{
var value = Expression.Lambda(node).Compile().DynamicInvoke();
SetValue(value);
}
return(node);
}
/// <summary>
/// 构建表达式
/// </summary>
/// <param name="param"></param>
/// <param name="expressionList"></param>
/// <returns></returns>
internal string Build(Dictionary <string, object> param, List <WhereExpression> expressionList)
{
Param = param;
foreach (var item in expressionList)
{
if ((!item.Equals(expressionList.First())))
{
WhereExpression.AppendFormat(" {0} ", WhereType.GetOperator(item.ExpressType));
}
if (!string.IsNullOrEmpty(item.StringWhere))
{
WhereExpression.Append(item.StringWhere);
continue;
}
Visit(item.LambdaWhere);
}
return(WhereExpression.ToString());
}
protected override Expression VisitUnary(UnaryExpression node)
{
if (node.NodeType == ExpressionType.Not)
{
WhereExpression.Append(WhereType.GetOperator(node.NodeType));
Visit(node.Operand);
}
else if (node.Operand.NodeType == ExpressionType.New)
{
var value = Expression.Lambda(node).Compile().DynamicInvoke();
SetValue(value);
}
else
{
Visit(node.Operand);
}
return(node);
}
