Question

我有一个具有int StateID字段和string StateName字段的viewmodel，如下所示：

public class DepartmentViewModel : BaseViewModel, IModelWithId
{
    // only show in edit mode
    public int StateId { get; set; }

    // only show in display mode
    public string StateName { get; set; }
}

我有一个使用DisplayForModel的只读视图和一个使用EditorForModel的更新视图。我希望DisplayForModel视图显示StateName属性，EditorForModel视图使用StateID属性（我实际上是基于此呈现下拉列表）。

我无法弄清楚如何修饰我的viewmodel属性来创建此行为。

Answer 1

对CodeGrue的回答发表评论。

使该属性继承IMetadataAware。这样您就不需要构建自己的DataAnnotationsModelMetadataProvider。

新属性将变为：

[AttributeUsage(AttributeTargets.Property, AllowMultiple = false, Inherited = true)]
public sealed class RenderModeAttribute : Attribute, IMetadataAware
{
    public RenderMode RenderMode { get; set; }

    public RenderModeAttribute(RenderMode renderMode)
    {
        RenderMode = renderMode;
    }

    public void OnMetadataCreated(ModelMetadata metadata)
    {
        switch (RenderMode)
        {
            case RenderMode.DisplayModeOnly:
                metadata.ShowForDisplay = true;
                metadata.ShowForEdit = false;
                break;

            case RenderMode.EditModeOnly:
                metadata.ShowForDisplay = false;
                metadata.ShowForEdit = true;
                break;

            case RenderMode.None:
                metadata.ShowForDisplay = false;
                metadata.ShowForEdit = false;
                break;
        }
    }
}

public enum RenderMode
{
    Any,
    EditModeOnly,
    DisplayModeOnly
}

Answer 2

我想要一个更通用的解决方案，所以我创建了一个新属性：

[AttributeUsage(AttributeTargets.Property, AllowMultiple = false, Inherited = true)]
public sealed class RenderModeAttribute : Attribute
{
    public RenderMode RenderMode { get; set; }

    public RenderModeAttribute(RenderMode renderMode)
    {
        RenderMode = renderMode;
    }
}

public enum RenderMode
{
    Any,
    EditModeOnly,
    DisplayModeOnly
}

在我的自定义DataAnnotationsModelMetadataProvider中包含以下代码：

var renderModeAttribute = attributes.OfType<RenderModeAttribute>();
if (renderModeAttribute.Any())
{
    var renderMode = renderModeAttribute.First().RenderMode;
    switch (renderMode)
    {
        case RenderMode.DisplayModeOnly:
            metadata.ShowForDisplay = true;
            metadata.ShowForEdit = false;
            break;
        case RenderMode.EditModeOnly:
            metadata.ShowForDisplay = false;
            metadata.ShowForEdit = true;
            break;
    }
}

所以我可以这样装饰我的模型：

public class DepartmentViewModel    
{     
    [RenderMode(RenderMode.EditModeOnly)]   
    public int StateId { get; set; }     

    [RenderMode(RenderMode.DisplayModeOnly)]    
    public string StateName { get; set; }     
}

Answer 3

这是我的自定义提供程序，我添加了无渲染模式

public class CustomModelMetadataProvider : DataAnnotationsModelMetadataProvider
{
    protected override ModelMetadata CreateMetadata(System.Collections.Generic.IEnumerable<System.Attribute> attributes, System.Type containerType, System.Func<object> modelAccessor, System.Type modelType, string propertyName)
    {
        var metadata = base.CreateMetadata(attributes, containerType, modelAccessor, modelType, propertyName);

        var renderModeAttribute = attributes.OfType<RenderModeAttribute>();
        if (renderModeAttribute.Any())
        {
            var renderMode = renderModeAttribute.First().RenderMode;
            switch (renderMode)
            {
                case RenderMode.DisplayModeOnly:
                    metadata.ShowForDisplay = true;
                    metadata.ShowForEdit = false;
                    break;

                case RenderMode.EditModeOnly:
                    metadata.ShowForDisplay = false;
                    metadata.ShowForEdit = true;
                    break;

                case RenderMode.None:
                    metadata.ShowForDisplay = false;
                    metadata.ShowForEdit = false;
                    break;
            }
        } 

        return metadata;
    }
}

Answer 4

覆盖模板：

在~/Shared/EditorTemplates/DepartmentViewModel.ascx put：

<%@ Control Language="C#" Inherits="System.Web.Mvc.ViewUserControl<Namespace.DepartmentViewModel>" %>
<%= Html.LabelFor(x => x.StateId) %>
<%= Html.TextBoxFor(x => x.StateId) %>

在您的~/Shared/DisplayTemplates/DepartmentViewModel.ascx：

中

<%@ Control Language="C#" Inherits="System.Web.Mvc.ViewUserControl<Namespace.DepartmentViewModel>" %>
<div><%= Html.Encode(Model.StateName) %></div>

在MVC2中的EditorForModel与DisplayForModel模式中显示不同的字段

4 个答案: