教程：在Orchard中建设自界说字段范例(2)

　　正如前文所说，字段范例其实是一种轻量级的部件。和部件一样它也需要一个驱动器（Driver）来处理惩罚它的泛起逻辑，只是它不需要处理惩罚器（Handler）来处理惩罚它的数据存储。因为Orchard框架已经帮我们实现了这一点。我们在此项目中添加一个Drivers目次，并在该目次下建设一个LocaleFieldDriver.cs文件，输入以下代码：

LocaleFieldDriver.cs
using System;
using JetBrains.Annotations;
using Orchard;
using Orchard.ContentManagement;
using Orchard.ContentManagement.Drivers;
using MyCompany.LocaleField.ViewModels;
using Orchard.Localization;

namespace MyCompany.LocaleField.Drivers
{
public class LocaleFieldDriver : ContentFieldDriver<Fields.LocaleField>
{
/// <summary>
/// 界说模板查找法则，在Views目次下凭据Fields/MyCompany.Locale法则查找模板
/// 好比显示画面就直接查找Fields目次下MyCompany.Locale.cshtml文件。（注：aspx模板也是支持的）
/// 编辑画面会查找EditorTemplates目次下的Fields\MyCompany.Locale.cshtml文件
/// </summary>
private const string TemplateName = "Fields/MyCompany.Locale"; // EditorTemplates/Fields/MyCompany.Locale.cshtml

/// <summary>
/// 获取字段前缀
/// 可以使编辑画面中各字段的表单控件都有独一的名称，不至于呈现同名斗嘴。
/// </summary>
/// <param name="field"></param>
/// <param name="part"></param>
/// <returns></returns>
private static string GetPrefix(ContentField field, ContentPart part)
{
return part.PartDefinition.Name + "." + field.Name;
}

/// <summary>
/// 显示画面
/// </summary>
/// <param name="part"></param>
/// <param name="field"></param>
/// <param name="displayType"></param>
/// <param name="shapeHelper"></param>
/// <returns></returns>
protected override DriverResult Display(ContentPart part, Fields.LocaleField field, string displayType, dynamic shapeHelper)
{
var value = field.Locale;

var viewModel = new LocaleFieldViewModel
{
Name = field.Name,
//所在数据由都市和地点组成，都市和地点用逗号脱离，如：上海,浦东新区张杨路XXX号
City = string.IsNullOrEmpty(value) ? "" : value.Substring(0, value.IndexOf(',')),
Address = string.IsNullOrEmpty(value) ? "" : value.Substring(value.IndexOf(',') + 1)
};

return ContentShape("Fields_MyCompany_Locale", // this is just a key in the Shape Table
() =>
shapeHelper.Fields_MyCompany_Locale( // Fields_MyCompany_Locale是一个动态范例，是视图Fields/MyCompany.Locale.cshtml的module，个中的Model属性，是LocaleFieldViewModel
Model: viewModel)
);
}

/// <summary>
/// 编辑画面显示
/// </summary>
/// <param name="part"></param>
/// <param name="field"></param>
/// <param name="shapeHelper"></param>
/// <returns></returns>
protected override DriverResult Editor(ContentPart part, Fields.LocaleField field, dynamic shapeHelper)
{

var value = field.Locale;

var viewModel = new LocaleFieldViewModel
{
Name = field.Name,
City = string.IsNullOrEmpty(value) ? "" : value.Substring(0, value.IndexOf(',')),
Address = string.IsNullOrEmpty(value) ? "" : value.Substring(value.IndexOf(',') + 1)
};

return ContentShape("Fields_MyCompany_Locale_Edit", // this is just a key in the Shape Table
() => shapeHelper.EditorTemplate(TemplateName: TemplateName, Model: viewModel, Prefix: GetPrefix(field, part)));
}

/// <summary>
/// 编辑画面Post
/// </summary>
/// <param name="part"></param>
/// <param name="field"></param>
/// <param name="updater"></param>
/// <param name="shapeHelper"></param>
/// <returns></returns>
protected override DriverResult Editor(ContentPart part, Fields.LocaleField field, IUpdateModel updater, dynamic shapeHelper)
{
var viewModel = new LocaleFieldViewModel();

if(updater.TryUpdateModel(viewModel, GetPrefix(field, part), null, null))
{
field.Locale = viewModel.City + "," + viewModel.Address;
}

return Editor(part, field, shapeHelper);
}
}