Expression <Func <T, bool> > CreateLambdaBinary(CRLExpression expression)
{
var left = expression.Left;
var right = expression.Right;
var creater = new LambdaCreater <T>();
var type = expression.ExpressionType;
var dic = new Dictionary <string, ExpressionHandler>();
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);
//todo 更多方法解析
if (!dic.ContainsKey(type))
{
throw new CRLException("没有对应的运算方法 " + type);
}
if (left.Type == CRLExpressionType.MethodCall)//按方法运算 如 b.NameSubstring,Indexof(0,1)=="123"
{
//按属性的子方法
var left2 = CreateLambdaMethodCall2(left);
var value = ObjectConvert.ConvertObject(left2.Type, right.Data);
return(dic[type](left2, value));
}
else//按属性运算 如b.Id==1
{
var member = creater.CreatePropertyExpression(left.Data.ToString());
return(dic[type](member, right.Data));
}
}
internal MethodCallExpression CreateLambdaMethodCall2(CRLExpression expression)
{
//表示二元运算的方法
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 CRLException("没有对应的方法 " + methodName);
}
return(dic[methodName](propertyName, args.Split(',')));
}
Expression <Func <T, bool> > CreateLambdaMethodCall(CRLExpression expression)
{
//表示方法调用
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("Contains", creater.Contains);
dic.Add("StartsWith", creater.StartsWith);
dic.Add("EndsWith", creater.EndsWith);
//todo 更多方法解析
if (!dic.ContainsKey(methodName))
{
throw new CRLException("没有对应的方法 " + methodName);
}
return(dic[methodName](propertyName, args.Split(',')));
}
public CRLExpressionVisitor()
{
//由于变量作用域的问题,只实例化一次,并且不能用缓存
creater = new LambdaCreater <T>();
}