Question

我有一个绑定到视图的对象。该对象具有一个带有布尔字段的项目列表。我使用此布尔值字段绑定到表单上的复选框。我希望用户选择他们想要的项目，然后提交。问题是，当它提交并传递到后期操作时，项目列表为空。

这是传递给视图的视图模型。

public class ReAssignVM
{
    public string ToUsername { get; set; }

    public string FromUsername { get; set; }

    public IEnumerable<ReAssignTaskVM> Tasks { get; set; }
}  // End of Class

这是视图：

    @model SRM.ClassLibrary.V1.ViewModels.TaskViewModels.ReAssignVM

@{
    ViewData["Title"] = "Re-Assign Tasks";
}

<h2>Re-Assign Tasks</h2>

<br />

<div class="row">
    <div class="col-md-1 alignRight">
        <b>From:</b>
    </div>
    <div class="col-md-3">
        @Model.FromUsername
    </div>
    <div class="col-md-1 alignRight">
        <b>To:</b>
    </div>
    <div class="col-md-3">
        @Model.ToUsername
    </div>
</div>

<br />

<form asp-action="ReAssignTasks">
    <input type="hidden" asp-for="FromUsername" />
    <input type="hidden" asp-for="ToUsername" />

    <div include-if="@Model.Tasks != null && Model.Tasks.Count() > 0">
        <table class="table table-hover">
            <thead class="thead-light">
                <tr>
                    <th></th>
                    <th>
                        Status
                    </th>
                    <th>
                        Date
                    </th>
                    <th>
                        Student
                    </th>
                    <th>
                        Description
                    </th>
                </tr>
            </thead>
            <tbody>
                @foreach (var task in Model.Tasks.OrderBy(n => n.TaskDate))
                {
                    <tr>
                        <td>
                            @Html.HiddenFor(item => task.TaskID)
                            @Html.CheckBoxFor(item => task.Assign)
                        </td>
                        <td>
                            @Html.DisplayFor(item => task.TaskStatus)
                        </td>
                        <td>
                            @task.TaskDate.ToLocalTime().ToString("M/d/yyyy")
                        </td>
                        <td>
                            @Html.DisplayFor(item => task.StudentUsername)
                        </td>
                        <td>
                            @Html.DisplayFor(item => task.Description)
                        </td>
                    </tr>
                }
            </tbody>
        </table>

        <br />

        <div class="row">
            <div class="col-md-12 alignRight">
                <button type="button" class="btn btn-primary" data-toggle="modal" data-target="#assignment">
                    Re-Assign
                </button>
            </div>
        </div>
    </div>

    <div class="modal fade" id="assignment" tabindex="-1" role="dialog" aria-labelledby="assignmentLabel" aria-hidden="true">
        <div class="modal-dialog" role="document">
            <div class="modal-content">
                <div class="modal-header">
                    <h5 class="modal-title" id="assignmentLabel">Confirm Re-Assignment of Tasks?</h5>
                    <button class="close" type="button" data-dismiss="modal" aria-label="Close">
                        <span aria-hidden="true">×</span>
                    </button>
                </div>
                <div class="modal-body">Selected tasks will be re-assigned from @Model.FromUsername to @Model.ToUsername</div>
                <div class="modal-footer">
                    <button class="btn btn-secondary" type="button" data-dismiss="modal">Cancel</button>
                    <input type="submit" value="Confirm" class="btn btn-primary" />
                </div>
            </div>
        </div>
    </div>
</form>

<div exclude-if="@Model.Tasks != null && Model.Tasks.Count() > 0">
    <div class="alert alert-info">
        There are no tasks to re-assign.
    </div>
</div>

有人可以帮助我了解如何正确执行此操作吗？

Answer 1

您将需要为您的Collection项目提供索引，以将其回发到模型中，因为Model活页夹将使用那些将对象绑定回行动。因此，您应该在视图中使用For循环和IList<T>作为模型：

@for(int i=0; i< Model.Tasks.Count(); i++)
{

     @Html.HiddenFor(item => Model.Tasks[i].TaskID)
     @Html.CheckBoxFor(item => Model.Tasks[i].Assign)

     ............
     ............
}

，然后在模型中将其更改为IList<T>，因为您在IEnumerable<T>上没有索引器：

public class ReAssignVM
{
    public string ToUsername { get; set; }

    public string FromUsername { get; set; }

    public IList<ReAssignTaskVM> Tasks { get; set; }
}  // End of Class

带有复选框的绑定列表并回发

1 个答案: