如何处理列上的转换

本文关键字：转换 处理 何处理 | 更新日期: 2023-09-27 18:05:04

我为我想要显示的网格的ActionResult设置了这个方法:

    public ActionResult ReadTransactions([DataSourceRequest] DataSourceRequest request)
    {
        var userInfo = new UserInfo(User.Identity);
        using (var ctx = new KassenautomatEntities())
        {
            var transactions = ctx.Protokoll.Where(e => e.KartenID == userInfo.CardId);
            var result = transactions.ToDataSourceResult(request);
            return Json(result);
        }
    }

这是我的视图:

@(Html.Kendo().Grid<WebInterface.Models.Protokoll>()
    .Name("Transactions")
    .Columns(columns =>
    {
        columns.Bound(o => o.Datum).Format("{0:dd.MM.yyyy HH:mm:ss}");
        columns.Bound(o => o.TransaktionTyp);
        columns.Bound(o => o.Betrag);
        columns.Bound(o => o.Client);
    })
    .Pageable()
    .Sortable()
    .Scrollable()
    .Filterable()
    .HtmlAttributes(new { style = "height:430px;" })
    .DataSource(dataSource => dataSource
        .Ajax()
        .PageSize(10)
        .Read(read => read.Action("ReadTransactions", "Transactions"))
     )
)

我遇到的问题是这一行视图:

columns.Bound(o => o.TransaktionTyp);

TransaktionTyp是一个整数，它引用了我想在这里显示的特定字符串。因此，我为它开发了以下enum:

    public enum TransactionType
    {
        Charged = 0,
        Debited = 1,
        CardBlocked = 2,
        CardEstablished = 3,
        ProtocolError = 4,
        PackageError = 5,
        CardCanceled = 6,
        CardFree = 7
    }

为了解决这个问题，我有以下方法:

    public static string TransactionTypeToDisplayName(TransactionType type)
    {
        switch (type)
        {
            case TransactionType.Charged:
                return "Aufgeladen";
            case TransactionType.Debited:
                return "Abgebucht";
            case TransactionType.CardBlocked:
                return "Karte gesperrt";
            case TransactionType.CardEstablished:
                return "Karte eingerichtet";
            case TransactionType.ProtocolError:
                return "Protokoll Fehler";
            case TransactionType.PackageError:
                return "Paket Fehler";
            case TransactionType.CardCanceled:
                return "Karte Storno";
            case TransactionType.CardFree:
                return "Karte Gratisabgabe";
            default:
                return "Unbekannte Transaktionstyp";
        }
    }

我的问题是，我如何使用我的TransactionTypeToDisplayName方法格式化我的列?

我想要的是这样的:

columns.Bound(o => TransactionTypeToDisplayName(o.TransaktionTyp))

如何处理列上的转换

好吧，这不是我想要的，但这是我最终的解决方案:

首先我写了一个扩展方法: 
using System;
using System.ComponentModel.DataAnnotations;
using System.Globalization;
using System.Linq;
using System.Linq.Expressions;
using System.Reflection;
using System.Web.Mvc;
using Kendo.Mvc.UI.Fluent;
namespace WebInterface.Core.Extension
{
    /// <summary>
    /// Erweiterungsmethoden für das KendoGrid
    /// </summary>
    public static class KendoGrid
    {
        /// <summary>
        /// Fügt der Tabelle eine Bindung mit einem Enum zu
        /// </summary>
        /// <typeparam name="TModel">Der Typ des Models</typeparam>
        /// <typeparam name="TEnum">Der Typ der Enumeration</typeparam>
        /// <param name="model">Das Model</param>
        /// <param name="expression">Die Expression</param>
        public static void Bound<TModel, TEnum>(this GridColumnFactory<TModel> model, Expression<Func<TModel, byte?>> expression)
            where TModel : class
            where TEnum : struct, IComparable, IFormattable, IConvertible
        {
            //Sicherstellen, dass es sich um einen Enum handelt
            if (!typeof(TEnum).IsEnum)
            {
                throw new ArgumentException("T must be an enumerated type");
            }
            //Die einzelnen Werte des Enums extrahieren
            var values = (TEnum[])System.Enum.GetValues(typeof(TEnum));
            //Eine Zuweisungsliste von Wert und Anzeigenamen erstellen
            var selectList = new SelectList(values.Select(value => new
            {
                value = Convert.ToInt32(value),
                displayName =
                    value.GetType()
                        .GetMember(value.ToString(CultureInfo.InvariantCulture))
                        .First()
                        .GetCustomAttribute<DisplayAttribute>()
                        .Name
            }), "value", "displayName");
            //Fügt die Spalte hinzu
            model.ForeignKey(expression, selectList);
        }
    }
}

第二部分是用Display Attributes重写枚举:

using System.ComponentModel.DataAnnotations;
namespace WebInterface.Core.Enum
{
    public class Transaction
    {
        /// <summary>
        /// Die Transaktionstypen
        /// </summary>
        public enum Type
        {
            [Display(Name = "Aufgeladen")]
            Charged = 0,
            [Display(Name = "Abgebucht")]
            Debited = 1,
            [Display(Name = "Karte Gesperrt")]
            CardBlocked = 2,
            [Display(Name = "Karte Eingerichtet")]
            CardEstablished = 3,
            [Display(Name = "Protokoll Fehler")]
            ProtocolError = 4,
            [Display(Name = "Paket Fehler")]
            PackageError = 5,
            [Display(Name = "Karte Storno")]
            CardCanceled = 6,
            [Display(Name = "Karte Gratisabgabe")]
            CardFree = 7
        }
    }
}
要绑定它，我们必须这样调用它: 
columns.Bound<Protokoll, Transaction.Type>(o => o.TransaktionTyp);

Protokoll为实体框架中的模型，Transaction.Type为枚举。

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