private static IOrderedQueryable <T> Sort <T>(this IQueryable <T> queryable, LambdaExpression lambdaExpression, MethodInfo methodInfo)
{
var exp = lambdaExpression.CheckNotNull(nameof(lambdaExpression)).Body;
var resultType = exp.Type;
var funcType = typeof(Func <,>).MakeGenericType(typeof(T), resultType);
var lambdaExpressionMethodInfo = MethodInfos.Expression.Lambda.MakeGenericMethod(funcType);
var funcExpression = lambdaExpressionMethodInfo.Invoke(null, new object[] { exp, lambdaExpression.Parameters.ToArray() });
var method = methodInfo.MakeGenericMethod(typeof(T), resultType);
var result = method.Invoke(null, new object[] { queryable, funcExpression });
return((IOrderedQueryable <T>)result);
}
/// <summary>
/// 提取成员信息
/// </summary>
/// <param name="expression">表达式</param>
public static MemberInfo ExtractMemberInfo(this LambdaExpression expression)
{
expression.CheckNotNull(nameof(expression));
MemberInfo info;
try
{
var lambda = expression;
var operand = lambda.Body is UnaryExpression body
? body.Operand as MemberExpression
: lambda.Body as MemberExpression;
var member = operand.Member;
info = member;
}
catch (Exception e)
{
throw new ArgumentNullException("属性或字段访问器表达式不是 “ o => o.Property” 格式", e);
}
return(info);
}
public static TPath BuildTPath(this LambdaExpression expr)
{
expr.CheckNotNull(nameof(expr));
return(TPath.Builder.Build(expr));
}