c# - Submit form with table - how to pass the selected row number on submit

Question

Here is the Model:

public class TestModel
{
    public string Data { get; set; }
    public List<string> Datas { get; set; }
}

Here is the view:

@model InventoryWeb.Models.TestModel

@using (Html.BeginForm())
{
    @Html.DisplayFor(modelItem => Model.Data)
    @Html.HiddenFor(m => m.Data)

    <table class="table">
        <tr>
            <th>
                Data
            </th>
            <th></th>
        </tr>
        @for (int i = 0; i < Model.Datas.Count; i++)
        {
            @Html.Hidden("Datas["+ i + "]", Model.Datas[i])
            <tr>
                <td>
                    @Html.DisplayFor(modelItem => Model.Datas[i])
                </td>
                <td>
                    <input type="submit" value="Submit" formaction="SubmitTest" formmethod="post"/>
                </td>
            </tr>
        }
    </table>
}

How to pass the selected row number (the number of row on which user pressed the "Submit" button) to controller? TempData/Viewbag/whatever it is possible to use to pass this info to Controller site when Submitting.

Answer 1

The way you wrote it, it will send all the data back to server for any row.

You can insert a form in each row:

@model InventoryWeb.Models.TestModel

@Html.DisplayFor(modelItem => Model.Data)

<table class="table">
    <tr>
        <th>
            Data
        </th>
        <th></th>
    </tr>
    @for (int i = 0; i < Model.Datas.Count; i++)
    {

        <tr>
            <td>
                @Html.DisplayFor(modelItem => Model.Datas[i])
            </td>
            <td>
    @using (Html.BeginForm())
    {
        @Html.Hidden("rowNumber", i)
                <input type="submit" value="Submit" formaction="SubmitTest" formmethod="post"/>
    }
            </td>
        </tr>
    }
</table>

But I prefer using javascript in this situations.

Edit

With JavaScript:

@using (Html.BeginForm("SubmitTest"))
{
    @Html.DisplayFor(modelItem => Model.Data)
    @Html.HiddenFor(m => m.Data)
    <input type="hidden" id="rowNumber" name="rowNumber" />

    <table class="table">
        <tr>
            <th>
                Data
            </th>
            <th></th>
        </tr>
        @for (int i = 0; i < Model.Datas.Count; i++)
        {
            @Html.Hidden("Datas["+ i + "]", Model.Datas[i])
            <tr>
                <td>
                    @Html.DisplayFor(modelItem => Model.Datas[i])
                </td>
                <td>
                    <input type="button" value="Submit" onclick="SubmitForm(@i, this);"/>
                </td>
            </tr>
        }
    </table>
}

<script>
function SubmitForm(i, btn){
    $("#rowNumber").val(i);
    var form = $(btn).closest("form");
    form.submit();
}
</script>