通过 RouteValueDictionary 发送单个值

Question

我的 ViewModel 的一个属性是一个数组，不幸的是，每次我发回控制器时它都是 null。我想出了一个简单的技巧，将值放入逗号分隔的字符串中。

这对我们的分页插件非常有用，它使用RouteValueDictionary 回发到我们的Index 方法。但是，它在Html.BeginForm 帮助器中不起作用，该帮助器回发到不同的控制器操作（Update 方法）。

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@*Since we can't send arrays or complex objects break array down into string for RouteValueDictionary*@
var channelCodes = "";
for (int i = 0; i < Model.searchChannelCode.Length; i++)
{
    channelCodes += Model.searchChannelCode[i];

    if (i + 1 < Model.searchChannelCode.Length)
    {
        channelCodes += ",";
    }
}  

@*The 'searchChannelCodesPagin' variable from this RouteValueDictionary always posts back as null
using (Html.BeginForm("Update", "ZipCodeTerritory", new RouteValueDictionary()
    {
        {"searchChannelCodesPaging", channelCodes }
    }, FormMethod.Post, new {id = "UpdateForm"}))
{
    @Html.HiddenFor(model => model.searchZip)
    @Html.HiddenFor(model => model.searchTerritory)
    @Html.HiddenFor(model => model.searchState)
    @Html.HiddenFor(model => model.searchActiveOnly)
    @Html.HiddenFor(model => model.zipCodeTerritory)

    <div id="cloneBox">
        <div id="rw1">
            @Html.LabelFor(model => model.newTerritory)
            @Html.TextBoxFor(model => model.newTerritory, new { style = "width: 30px;padding-left:10px;", maxLength = 3 })
            @Html.LabelFor(model => model.newDescription)
            @Html.TextBoxFor(model => model.newDescription, new { style = "width: 250px;padding-left:10px;", maxLength = 30 })  
            @Html.LabelFor(model => model.newEffectiveDate)     
            @Html.TextBoxFor(model => model.newEffectiveDate, new { style = "width: 80px;padding-left:10px;" }) 
            <div id="rw2" style="padding-top: 10px;">
                @Html.LabelFor(model => model.newChannelCode)
                @Html.DropDownListFor(model => model.newChannelCode, Model.ChannelCodes, " ")
                @Html.LabelFor(model => model.newStateCode)
                @Html.DropDownListFor(model => model.newStateCode, Model.StateCodes, "  ")
                @Html.LabelFor(model => model.newEndDate)
                @Html.TextBoxFor(model => model.newEndDate, new { style = "width: 80px;" })
            </div>                                 
        </div>
    </div>
    <br/>
    <div id="buttonDiv">
        <button type="submit" id="CloneButton" name="button" value="clone">Apply New Data</button>
        <button type="submit" id="deleteButton" name="button" value="delete">Delete Selected Items</button> 
        <button type="submit" id="removeButton" name="button" value="removeErrors">Remove Selected Errors</button>           
    </div>

}

控制器

上面的形式发布到这个控制器动作。 searchChannelCodePaging 变量每次都为空。

    [HttpPost]
    public ActionResult Update(ZipCodeIndex updateZip, string button, string searchChannelCodesPaging)
    {

Answer 1

由于您正在发布帖子，因此将其发送到后端的最简单方法是添加隐藏字段：

@Html.HiddenFor("searchChannelCodesPaging", searchChannelCodesPaging);

作为路由值，您可能需要通过以下两种方法之一在控件中显式获取它。这些对象可以在 Controller 类中直接访问。

RouteData.Values("searchChannelCodesPaging")
Request.QueryString.Get("searchChannelCodesPaging");

Answer 2

您不必将数组类型模型参数序列化为 CSV 字符串即可将其发布到您的控制器。你可以这样做：

@for (var i = 0; i < Model.searchChannelCode.Length; i++)
{
    @Html.HiddenFor(m => m.searchChannelCode[i]);
}