public static IQueryable <T> OrderBy <T>(this IQueryable <T> source, string sortProperty, ListSortDirection sortOrder)
{
var type = typeof(T);
var property = type.GetProperty(sortProperty);
var parameter = Expression.Parameter(type, "p");
var propertyAccess = Expression.MakeMemberAccess(parameter, property);
var orderByExp = Expression.Lambda(propertyAccess, parameter);
var typeArguments = new[] { type, property.PropertyType };
var methodName = sortOrder == ListSortDirection.Ascending ? "OrderBy" : "OrderByDescending";
var resultExp = Expression.Call(typeof(Queryable), methodName, typeArguments, source.Expression, Expression.Quote(orderByExp));
return(source.Provider.CreateQuery <T>(resultExp));
}
/// <summary>
/// 动态组合多排序字段
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="query"></param>
/// <param name="orderByExpression"></param>
/// <returns></returns>
public static IQueryable <T> ExpressionOrderBy <T>(this IQueryable <T> query, params Qian.Models.OrderModelField[] orderByExpression)
{
var parameter = Expression.Parameter(typeof(T), "o");
if (orderByExpression != null && orderByExpression.Length > 0)
{
for (int i = 0; i < orderByExpression.Length; i++)
{
//根据属性名获取属性
var property = typeof(T).GetProperty(orderByExpression[i].propertyName);
//创建一个访问属性的表达式
var propertyAccess = Expression.MakeMemberAccess(parameter, property);
var orderByExp = Expression.Lambda(propertyAccess, parameter);
string OrderName = orderByExpression[i].isAsc ? "OrderBy" : "OrderByDescending";
if (i > 0)
{
OrderName = orderByExpression[i].isAsc ? "ThenBy" : "ThenByDescending";
}
else
{
OrderName = orderByExpression[i].isAsc ? "OrderBy" : "OrderByDescending";
}
MethodCallExpression resultExp = Expression.Call(typeof(Queryable), OrderName, new Type[] { typeof(T), property.PropertyType }, query.Expression, Expression.Quote(orderByExp));
query = query.Provider.CreateQuery <T>(resultExp);
}
}
return(query);
}
public static IQueryable <TEntity> OrderBy <TEntity>(this IQueryable <TEntity> source, string orderByProperty,
string orderAs) where TEntity : class
{
if (string.IsNullOrWhiteSpace(orderByProperty))
{
orderByProperty = "Id";
}
string command = "desc".Equals(orderAs) ? "OrderByDescending" : "OrderBy";
var type = typeof(TEntity);
var property = type.GetProperty(orderByProperty);
var parameter = Expression.Parameter(type, "p");
var propertyAccess = Expression.MakeMemberAccess(parameter, property);
var orderByExpression = Expression.Lambda(propertyAccess, parameter);
var resultExpression = Expression.Call(typeof(Queryable), command, new Type[] { type, property.PropertyType }, source.Expression, Expression.Quote(orderByExpression));
return(source.Provider.CreateQuery <TEntity>(resultExpression));
}
