在创建新视图时的SelectList价值DropDownListFor不设置 [英] DropDownListFor value not setting when creating new SelectList in view

问题描述

【举例】＃1（这个工作）

Example #1 (this one works)

@Html.DropDownListFor(m => m.State.Id, Model.States)

我的控制器中像这样的第一个例子创建选择列表。

I'm creating the SelectList in the controller for the first example like this.

var states = Repository.GetStates();
var statesSelectList = new SelectList(states, "Id", "Name");

//model.States is a SelectList
model.States = statesSelectList;

例2（这不设置负载所选值）

Example #2 (this doesn't set the selected value on load)

@Html.DropDownListFor(m => m.State.Id, new SelectList(Model.States, "Id", "Name"))

我创建在第二个例子中的视图选择列表，以及控制器看起来是这样的。

I'm creating the SelectList in the view for the second example, and the controller looks like this.

//model.States is a List<State>.
model.States = Repository.GetStates();

这似乎必须有一些简单的我失踪。让我知道如果我需要澄清任何东西。谢谢你。

It seems there must be something simple that I'm missing. Let me know if I need to clarify anything else. Thanks.

推荐答案

属性添加到您的视图模型：

Add a property to your view model:

private int? stateId;
public int StateId
{
    get { return stateId ?? State.Id; }
    set { stateId = value; }
}

然后在您的Razor视图：

Then in your Razor view:

@Html.DropDownListFor(m => m.StateId, new SelectList(Model.States, "Id", "Name"))

最后在你的控制器POST操作：

And finally in your controller POST action:

model.State = Repository.GetState(model.StateId);

这篇关于在创建新视图时的SelectList价值DropDownListFor不设置的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！