使用SelectList进行模型绑定 [英] Modelbinding with SelectList

问题描述

我使用Html.DropDownList(string NameSelectListInViewData)方法创建一个DropDown. 这将生成具有正确值的有效选择"输入.一切都很好.

I create a DropDown with the Html.DropDownList(string NameSelectListInViewData) method. This generates a valid Select input with the correct values. And all is well.

但是，提交后，源SelectList中的值未绑定.

Upon submit however, the value in the source SelectList is not bound.

案例: ViewData.SearchBag.FamilyCodes:

Case: ViewData.SearchBag.FamilyCodes:

public SelectList FamilyCodes { get; set; }

生成下拉列表的HTML

Html that generates the dropdown:

<%=Html.DropDownList("SearchBag.FamilyCodes")%>

生成的html:

<select id="SearchBag.FamilyCodes" name="SearchBag.FamilyCodes">
    <option value=" ">Any</option>
    <option value="A">BLUE</option>
    <option value="B">BLACK</option>
    <option value="C">BEIGE</option>
    <option value="G">GREEN</option>
    <option value="O">ORANGE</option>
    <option value="P">PURPLE</option>
    <option value="R">RED</option>
    <option value="S">GRAY</option>
    <option value="U">BROWN</option>
    <option value="W">WHITE</option>
    <option value="Y">YELLOW</option>
</select>

在我的控制器中，我有一个带有参数searchBag的动作.

In my controller I have an action with a parameter searchBag.

public ActionResult AdvancedSearch(SearchBag searchBag) { 
    //Do Stuff with parameters in searchBag
    return View("AdvancedSearch", searchViewData);
}

所有其他字段都可以绑定，只有选择框不可以. 有什么想法吗?

All other fields bind just fine, only the selection boxes don't. Any ideas?

更新
对于将来的读者，值得阅读此博客文章:

UPDATE
For future readers it might be worth it to read this blog post: http://haacked.com/archive/0001/01/01/model-binding-to-a-list.aspx

推荐答案

昨天在选择列表中遇到了类似的问题，该列表会生成很好的列表，只是在UpdateModel上会失败=-未绑定?

Had a similar issue yesterday with select lists, the list would generate fine, just that on UpdateModel- would fail =- not bound?

然后我在参数列表中找到了答案...

And i found the answer in the parameters list...

SelectList (
Collection - items to use in the  drop down,
ValueField - ie the primarykey as a String,
NameField  - ie the name of the thing as a String,
SelectedValue -  which is the passed in current objects FK relationship)

所以对我来说...

Country = new SelectList(db.Countries，"pkCountry"，"CountryName"，address.fkCountry);

Country = new SelectList(db.Countries, "pkCountry", "CountryName",address.fkCountry);

我使用ViewModel方法-并将其包含在视图模型的构造函数中...

I use the ViewModel approach - and have this in the constructor of the view Model...

public AddressCountryViewModel(){
public SelectList Countrys {get; private set;}
public AddressCountryViewModel(Address address)
{
     Countrys = new SelectList(db.Countries, "pkCountry", "CountryName",address.fkCountry);
}

然后我在控制器 Edit Action 中获取值，并分配回要更新的对象...

I then grab the values in the controllers Edit Action and assign back to the object that is updating...

address.fkCountry = Convert.ToInt32(collection["fkCountry"]);

这篇关于使用SelectList进行模型绑定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！