public static IQueryable <T> ThenInclude <T>(this IQueryable <T> source, IncludeExpressionInfo info)
{
_ = info ?? throw new ArgumentNullException(nameof(info));
_ = info.PreviousPropertyType ?? throw new ArgumentNullException(nameof(info.PreviousPropertyType));
var exp = source.Expression as MethodCallExpression;
var arg = exp.Arguments[0] as ConstantExpression;
string previousPropertyName;
if (arg.Value is string)
{
previousPropertyName = arg.Value.ToString();
}
else
{
// System.Data.Entity.Core.Objects.Span is an internal class, so here's some reflection to get to the previous property.
var propertyInfo = arg.Value.GetType().GetProperty("SpanList", BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance);
var spanList = propertyInfo.GetValue(arg.Value);
// Get the first item of the span list
propertyInfo = propertyInfo.PropertyType.GetProperty("Item");
var spanPath = propertyInfo.GetValue(spanList, new object[] { 0 });
var fieldInfo = spanPath.GetType().GetField("Navigations", BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance);
var navigations = fieldInfo.GetValue(spanPath) as List <string>;
previousPropertyName = string.Join(".", navigations);
}
var propertyName = GetPropertyName(info.LambdaExpression);
return(QueryableExtensions.Include(source, $"{previousPropertyName}.{propertyName}"));
}
public static IQueryable <T> Include <T>(this IQueryable <T> source, IncludeExpressionInfo info)
{
_ = info ?? throw new ArgumentNullException(nameof(info));
var propertyName = GetPropertyName(info.LambdaExpression);
return(QueryableExtensions.Include(source, propertyName));
}
/// <summary>
/// Include
/// </summary>
/// <typeparam name="T"></typeparam>
/// <typeparam name="TProperty"></typeparam>
/// <param name="specificationBuilder"></param>
/// <param name="includeExpression"></param>
/// <returns></returns>
public static IIncludableSpecificationBuilder <T, TProperty> Include <T, TProperty>(this ISpecificationBuilder <T> specificationBuilder, Expression <Func <T, TProperty> > includeExpression)
{
var info = new IncludeExpressionInfo(includeExpression, typeof(T), typeof(TProperty));
((List <IncludeExpressionInfo>)specificationBuilder.Specification.IncludeExpressions).Add(info);
var includeBuilder = new IncludableSpecificationBuilder <T, TProperty>(specificationBuilder.Specification);
return(includeBuilder);
}
/// <summary>
///
/// </summary>
/// <typeparam name="TEntity"></typeparam>
/// <typeparam name="TPreviousProperty"></typeparam>
/// <typeparam name="TProperty"></typeparam>
/// <param name="previousBuilder"></param>
/// <param name="thenIncludeExpression"></param>
/// <returns></returns>
public static IIncludableSpecificationBuilder <TEntity, TProperty> ThenInclude <TEntity, TPreviousProperty, TProperty>(
this IIncludableSpecificationBuilder <TEntity, IEnumerable <TPreviousProperty> > previousBuilder,
Expression <Func <TPreviousProperty, TProperty> > thenIncludeExpression)
where TEntity : class
{
var info = new IncludeExpressionInfo(thenIncludeExpression, typeof(TEntity), typeof(TProperty), typeof(TPreviousProperty));
((List <IncludeExpressionInfo>)previousBuilder.Specification.IncludeExpressions).Add(info);
var includeBuilder = new IncludableSpecificationBuilder <TEntity, TProperty>(previousBuilder.Specification);
return(includeBuilder);
}
/// <summary>
/// 加载导航属性
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="source"></param>
/// <param name="info"></param>
/// <returns></returns>
public static IQueryable <T> Include <T>(this IQueryable <T> source, IncludeExpressionInfo info)
{
_ = info ?? throw new ArgumentNullException(nameof(info));
var queryExpr = Expression.Call(
typeof(EntityFrameworkQueryableExtensions),
"Include",
new Type[] {
info.EntityType,
info.PropertyType
},
source.Expression,
info.LambdaExpression
);
return(source.Provider.CreateQuery <T>(queryExpr));
}
