在ASP.NET中使用Lambda进行主/明细下拉过滤 [英] Master/Detail dropdown filtering using Lambda in ASP.NET

问题描述

我想根据上一个字段中选择的内容填充一个下拉列表.

I'd like to populate a dropdown list based on the selection chosen in the previous field.

目前，我的 ViewModel 中有2个列表，如下所示:

Currently I have 2 Lists from my ViewModel like so:

Manufacturers = context.ManufacturersTable.OrderBy(x => x.ManufacturerName).ToList(),
Models = context.ModelsTable.OrderBy(x => x.ModelName).ToList(),

两个列表都使用具有自己数据模型的SQL表填充.

Both lists are populated using a SQL Table with their own data model.

在 Models 表中，我有一个 ManufacturerID 列，该列与 Manufacturers 中的 ManufacturerID 匹配.>表格.

In the Models table, I have a column for ManufacturerID which matches that of the ManufacturerID in the Manufacturers table.

我想根据对 Manufacturers 列表的选择来填充 Models 列表，以便仅显示与所选制造商关联的模型.

I'd like to populate the Models list based on the selection of the Manufacturers list so that only models associated with the selected manufacturer are displayed.

我该如何使用 Lambda ?

我一直在玩哪里"和选择"，但还没完全能够到达那里.

I've been playing with Where and Select but haven't quite been able to get there.

这是桌子

MANUFACTURER   |   MANUFACTURER_ID
Manufacturer 1     GUID1
Manufacturer 2     GUID2

MODEL   |    MODEL_ID    |    MANUFACTURER_ID
Model 1 | GUID1          |    GUID1
Model 2 | GUID2          |    GUID2
Model 3 | GUID3          |    GUID1
Model 4 | GUID4          |    GUID1

推荐答案

context.ModelsTable.Where(x => x.ManufacturerId == value).OrderBy(x => x.ModelName).ToList()

这行不通吗?将ManufactureId作为 value 传递.此处关键字过滤数据，但返回表中的所有列.使用 Select ，您可以选择要返回的列.您可以一起使用这些关键字.

This doesn't work? Pass ManufactureId as value. Where keyword filter data but returns all columns from the table. With Select you can select which columns you want to return. You can use these keywords together.

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