Question

我想创建扩展方法

static IUpdatable<T> Set<T>(this IUpdatable<T> list, T item) where T : class

将崩溃：

db.Orders
.Where(o => o.OrderId == order.OrderId)
.Where(o => o.RowVersion == order.RowVersion)
.Set(o => o.AvgDeliveryTime, order.AvgDeliveryTime)
.Set(o => o.AvgSellerTime, order.AvgSellerTime)
.Set(o => o.BuyerId, order.BuyerId)
// There are other properties
.Set(o => o.ProductName, order.ProductName)
.Set(o => o.QuantityLot, order.QuantityLot)
.Set(o => o.SellerOrderId, order.SellerOrderId)
.Update();

到此：

db.Orders
.Where(o => o.OrderId == order.OrderId)
.Where(o => o.RowVersion == order.RowVersion)
.Set(o => o, order)
.Update();

它应该能够为每个属性添加Set-method。如何实现这种方法？

UPD：像这样：

    public static IUpdatable<T> Set<T>(this IUpdatable<T> list, T item) where T : class 
    {
        PropertyInfo[] props = typeof (T).GetProperties();

        var result = list;

        foreach (PropertyInfo prop in props)
        {
            result = result.Set(i=>prop.GetSetMethod(false), prop.GetValue(item, prop.Name) ); // This is wrong
        }

        return result;
    }

UPD2： Set-method的重载：

    public static IUpdatable<T> Set<T, TV>(this IQueryable<T> source, Expression<Func<T, TV>> extract, Expression<Func<T, TV>> update);
    public static IUpdatable<T> Set<T, TV>(this IQueryable<T> source, Expression<Func<T, TV>> extract, Expression<Func<TV>> update);
    public static IUpdatable<T> Set<T, TV>(this IQueryable<T> source, Expression<Func<T, TV>> extract, TV value);
    public static IUpdatable<T> Set<T, TV>(this IUpdatable<T> source, Expression<Func<T, TV>> extract, Expression<Func<T, TV>> update);
    public static IUpdatable<T> Set<T, TV>(this IUpdatable<T> source, Expression<Func<T, TV>> extract, Expression<Func<TV>> update);
    public static IUpdatable<T> Set<T, TV>(this IUpdatable<T> source, Expression<Func<T, TV>> extract, TV value);

创建扩展方法以设置所有属性

0 个答案: