create many DropDownListFor in foreach-loop [duplicate]

Answer 1

You should probably be using EditorTemplates. These allow you to do excatly what you're describing. If you create a strongly-typed partial view in ~/Views/Shared/EditorTemplates/Material_Select.cshtml (the view has to be named the same as the model) that looks like:

@model Material_Select

<div class="editor-label">
    @Html.LabelFor(m => m.MaterialId)
</div>
<div class="editor-field">
    @Html.DropDownListFor(m => m.MaterialId, Model.selectList)
</div>

Then in your overall form you can just call:

@Html.EditorFor(m => m.materialSelect)

Which will automatically enumerate your collection and render the editor template for each item in the collection.

Answer 2

Assuming count start in 0, and your action post method receive a parameter of type ViewModel, you can try this for bind the MaterialId for each dropdown:

foreach (var item in Model.materialSelect)
{
    count++;
    <div class="editor-label">
       Name for de dropdown
    </div>
    <div class="editor-field">
        @Html.DropDownList("materialSelect[" + count + "].MaterialId ", item.selectList)
        @Html.ValidationMessageFor(model => model.gradationId)
    </div>       
}