CRLExpression BinaryExpressionHandler(Expression left, Expression right, ExpressionType type, int level = 1)
{
var types = new ExpressionType[] { ExpressionType.Equal, ExpressionType.GreaterThan, ExpressionType.GreaterThanOrEqual, ExpressionType.LessThan, ExpressionType.LessThanOrEqual, ExpressionType.NotEqual };
var leftPar = RouteExpressionHandler(left);
var isRight = types.Contains(type);
var rightPar = RouteExpressionHandler(right, isRight, level);
var e = new CRLExpression()
{
ExpressionType = type.ToString(), Left = leftPar, Right = rightPar, Type = isRight ? CRLExpressionType.Binary : CRLExpressionType.Tree
};
return(e);
}
Expression <Func <T, bool> > CreateLambdaTree(CRLExpression expression)
{
var expression1 = CreateLambda(expression.Left);
var expression2 = CreateLambda(expression.Right);
if (expression.ExpressionType == "AndAlso")
{
return(expression1.Compose(expression2, Expression.AndAlso));
}
else
{
return(expression1.Compose(expression2, Expression.OrElse));
}
return(null);
}
/// <summary>
/// 转换为Lambda表达式
/// </summary>
/// <param name="expression"></param>
/// <returns></returns>
public Expression <Func <T, bool> > CreateLambda(CRLExpression expression)
{
if (expression.Type == CRLExpressionType.Tree)
{
return(CreateLambdaTree(expression));
}
else if (expression.Type == CRLExpressionType.MethodCall)
{
return(CreateLambdaMethodCall(expression));
}
else
{
return(CreateLambdaBinary(expression));
}
}
internal MethodCallExpression CreateLambdaMethodCall2(CRLExpression expression)
{
var creater = new LambdaCreater <T>();
var arry = expression.Data.ToString().Split('|');
var propertyName = arry[0];
var methodName = arry[1];
var args = expression.Data.ToString().Substring(propertyName.Length + methodName.Length + 2);
var dic = new Dictionary <string, MethodResultHandler>();
dic.Add("Substring", creater.Substring);
dic.Add("IndexOf", creater.IndexOf);
if (!dic.ContainsKey(methodName))
{
throw new Exception("没有对应的方法 " + methodName);
}
return(dic[methodName](propertyName, args.Split(',')));
}
Expression <Func <T, bool> > CreateLambdaMethodCall(CRLExpression expression)
{
var creater = new LambdaCreater <T>();
var arry = expression.Data.ToString().Split('|');
var propertyName = arry[0];
var methodName = arry[1];
var args = expression.Data.ToString().Substring(propertyName.Length + methodName.Length + 2);
var dic = new Dictionary <string, MethodHandler>();
dic.Add("Like", creater.Contains);
dic.Add("Contains", creater.Contains);
dic.Add("StartsWith", creater.StartsWith);
dic.Add("EndsWith", creater.EndsWith);
if (!dic.ContainsKey(methodName))
{
throw new Exception("没有对应的方法 " + methodName);
}
return(dic[methodName](propertyName, args.Split(',')));
}
Expression <Func <T, bool> > CreateLambdaBinary(CRLExpression expression)
{
var left = expression.Left;
var right = expression.Right;
var creater = new LambdaCreater <T>();
var type = expression.ExpressionType;
if (left.Type == CRLExpressionType.MethodCall)//按方法 如 Substring,Indexof
{
var dic = new Dictionary <string, BinaryMethodHandler>();
dic.Add("Equal", creater.Equal);
dic.Add("NotEqual", creater.NotEqual);
dic.Add("Greater", creater.Greater);
dic.Add("Less", creater.Less);
dic.Add("GreaterThan", creater.GreaterThan);
dic.Add("LessThan", creater.LessThan);
if (!dic.ContainsKey(type))
{
throw new Exception("没有对应的运算方法 " + type);
}
var left2 = CreateLambdaMethodCall2(left);
var value = ObjectConvert.ConvertObject(left2.Type, right.Data);
return(dic[type](left2, value));
}
else
{
var dic = new Dictionary <string, BinaryHandler>();
dic.Add("Equal", creater.Equal);
dic.Add("NotEqual", creater.NotEqual);
dic.Add("Greater", creater.Greater);
dic.Add("Less", creater.Less);
dic.Add("GreaterThan", creater.GreaterThan);
dic.Add("LessThan", creater.LessThan);
if (!dic.ContainsKey(type))
{
throw new Exception("没有对应的运算方法 " + type);
}
return(dic[type](left.Data.ToString(), right.Data));
}
}