我要评论 private static void getexpression<t2>(expression expression)
{
if (expression.nodetype != expressiontype.constant)
{
var _expression = expression as binaryexpression;
if (_expression == null || expression.nodetype == expressiontype.lambda)
{
_expression = getbinaryexpression(expression);
}
if (anybinaryoperator(_expression.nodetype))
{
var _leftexpression = _expression.left;
getexpression<t2>(_leftexpression);
var _rightexpression = _expression.right;
getexpression<t2>(_rightexpression);
}
else
{
results.add(getexpressionresult<t2>(_expression));
}
}
}
/// <summary>
/// escape to the lambda
/// </summary>
private static binaryexpression getbinaryexpression(expression expression)
{
lambdaexpression lambda = expression as lambdaexpression;
var lambdaexpression = lambda.body;
return lambdaexpression as binaryexpression;
}
/// <summary>
/// get result
/// </summary>
private static expressionresult getexpressionresult<t2>(binaryexpression expression)
{
var left_name = getleftexpression<t2>(expression);
var right_name = getrightexpression(expression);
return new expressionlambdaresult()
{
expressiontype = expression.nodetype,
propertyname = left_name,
propertyvalue = right_name
};
}
/// <summary>
/// get dto attribute
/// </summary>
private static string getleftexpression<t2>(binaryexpression expression)
{
var leftexpression = expression.left as memberexpression;
var ps = typeof(t2).getproperties(bindingflags.declaredonly | bindingflags.public | bindingflags.nonpublic | bindingflags.static | bindingflags.instance);
var first = ps.where(x => x.getcustomattribute<entitydatanameattribute>(true) != null && x.name.tolower() == leftexpression.member.name.tolower()).firstordefault();
return first != null ? first.getcustomattribute<entitydatanameattribute>(true).entitydataname : leftexpression.member.name;
}
/// <summary>
/// get constant value
/// </summary>
private static object getrightexpression(binaryexpression expression)
{
var rootexpression = expression.right as memberexpression;
var constexpr = rootexpression.expression as constantexpression;
if (constexpr == null)
{
object value = expression.lambda(expression.right).compile().dynamicinvoke();
if (value == null) return value = string.empty;
if (getpropertytype(value.gettype()) == typeof(nullable))
{
var ps = value.gettype().getproperties(bindingflags.declaredonly | bindingflags.public | bindingflags.nonpublic | bindingflags.static | bindingflags.instance);
var first = ps.where(x => x.getcustomattribute<entitydatanameattribute>(true) != null).firstordefault();
if (first == null)
{
throw new exception(" attribute is empty ");
}
value = value.gettype().getproperty(first.name).getvalue(value, null);
}
else if (getpropertytype(value.gettype()) == typeof(listclass))
{
}
return value;
}
else
{
var memberinfos = new stack<memberinfo>();
memberinfos.push(rootexpression.member);
object objreference = constexpr.value;
var mi = memberinfos.pop();
var objfield = objreference.gettype().getfield(mi.name);
return objfield.getvalue(objreference);
}
}
/// <summary>
/// any binary operator
/// </summary>
/// <param name="expressiontype"></param>
/// <returns></returns>
private static bool anybinaryoperator(expressiontype expressiontype)
{
bool any = true;
switch (expressiontype)
{
case expressiontype.andalso: break;
case expressiontype.and: break;
case expressiontype.orelse: break;
case expressiontype.or:break;
default:
any = !any;
break;
}
return any;
}
public class expressionlambdaresult: expressionresult
{
public string propertyname { get; set; }
public object propertyvalue { get; set; }
}
public class expressionresult
{
public expressiontype expressiontype { get; set; }
}
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