C# Fluent API:引用类型相互获取值
我目前正在为MVC编写一个网格,它是一个HtmlHelper扩展,我遇到了一个奇怪的问题 首先,这是我正在使用的构建网格的代码:C# Fluent API:引用类型相互获取值,c#,asp.net-mvc,html-helper,fluent-interface,C#,Asp.net Mvc,Html Helper,Fluent Interface,我目前正在为MVC编写一个网格,它是一个HtmlHelper扩展,我遇到了一个奇怪的问题 首先,这是我正在使用的构建网格的代码: RenderedOutput = HtmlHelper.GridFor(Model) .WithColumns(column => { column.Bind(x => x.Name) .WithCss("inline"); column.Bind(x => x.Age) .WithCss("inlin
RenderedOutput = HtmlHelper.GridFor(Model)
.WithColumns(column =>
{
column.Bind(x => x.Name)
.WithCss("inline");
column.Bind(x => x.Age)
.WithCss("inline fixed right");
})
.Render();
现在,整个fluent API是通过使用接口构建的,为了使复制过去的工作变得更小,我不在这里发布接口,但我将发布实现:
首先,HtmlHelper:
public static IGridBuilder<TEntity> GridFor<TModel, TEntity>(this HtmlHelper<TModel> htmlHelper,
IEnumerable<TEntity> dataSource)
{
return new GridBuilder<TEntity>(htmlHelper, dataSource);
}
publicstaticigridbuildergridfor(此HtmlHelper HtmlHelper,
IEnumerable数据源)
{
返回新的GridBuilder(htmlHelper,数据源);
}
这将返回一个GridBuilder,其实现如下:
#region Constructors
public GridBuilder(HtmlHelper helper, IEnumerable<TModel> data)
{
HtmlHelper = helper;
DataSource = data;
ColumnBuilders = new List<IColumnBuilder<TModel>>();
}
#endregion
#region Properties
private string Id { get; set; }
#endregion
#region IGridBuilder Members
public IList<IColumnBuilder<TModel>> ColumnBuilders { get; protected set; }
public IEnumerable<TModel> DataSource { get; private set; }
public HtmlHelper HtmlHelper { get; private set; }
public IGridBuilder<TModel> WithId(string id)
{
Id = id;
return this;
}
public IGridBuilder<TModel> WithColumns(Action<IColumnBuilder<TModel>> bindAllColumns)
{
bindAllColumns(new ColumnBuilder<TModel>(this));
return this;
}
public HtmlString Render()
{
var outputBuilder = new StringBuilder();
var headerMember = new TagBuilder("div");
headerMember.MergeAttribute("class", "gridHolder v-scroll");
if (!string.IsNullOrEmpty(Id))
{
headerMember.GenerateId(Id);
}
outputBuilder.AppendLine(headerMember.ToString(TagRenderMode.StartTag));
// Process all the available columns.
var rowBuilder = new TagBuilder("div");
rowBuilder.MergeAttribute("class", "row");
outputBuilder.AppendLine(rowBuilder.ToString(TagRenderMode.StartTag));
foreach (var column in ColumnBuilders)
{
var columnBuilder = new TagBuilder("div");
outputBuilder.AppendLine(columnBuilder.ToString(TagRenderMode.StartTag));
outputBuilder.AppendLine(columnBuilder.ToString(TagRenderMode.EndTag));
}
outputBuilder.AppendLine(rowBuilder.ToString(TagRenderMode.EndTag));
outputBuilder.AppendLine(headerMember.ToString(TagRenderMode.EndTag));
return new HtmlString(outputBuilder.ToString());
}
#endregion
#区域构造函数
公共网格生成器(HtmlHelper助手,IEnumerable数据)
{
HtmlHelper=助手;
数据源=数据;
ColumnBuilders=新列表();
}
#端区
#区域属性
私有字符串Id{get;set;}
#端区
#区域构建器成员
公共IList列生成器{get;protected set;}
公共IEnumerable数据源{get;private set;}
公共HtmlHelper HtmlHelper{get;私有集;}
id为(字符串id)的公共IGridBuilder
{
Id=Id;
归还这个;
}
带列的公共IGridBuilder(操作bindAllColumns)
{
bindAllColumns(新ColumnBuilder(this));
归还这个;
}
公共HtmlString Render()
{
var outputBuilder=新的StringBuilder();
var headerMember=新标记生成器(“div”);
headerMember.MergeAttribute(“类”、“网格持有者v形卷轴”);
如果(!string.IsNullOrEmpty(Id))
{
生成Id(Id)的校长成员;
}
outputBuilder.AppendLine(headerMember.ToString(TagRenderMode.StartTag));
//处理所有可用列。
var rowBuilder=新标记生成器(“div”);
合并属性(“类”、“行”);
AppendLine(rowBuilder.ToString(TagRenderMode.StartTag));
foreach(ColumnBuilders中的var列)
{
var columnBuilder=新标记生成器(“div”);
AppendLine(columnBuilder.ToString(TagRenderMode.StartTag));
AppendLine(columnBuilder.ToString(TagRenderMode.EndTag));
}
AppendLine(rowBuilder.ToString(TagRenderMode.EndTag));
AppendLine(headerMember.ToString(TagRenderMode.EndTag));
返回新的HtmlString(outputBuilder.ToString());
}
#端区
}
GridBuilder执行IColumnBuilder的操作来构建列,因此如下所示:
public class ColumnBuilder<TModel> : IColumnBuilder<TModel>
{
#region Constructors
public ColumnBuilder(IGridBuilder<TModel> gridBuilder)
{
GridBuilderReference = gridBuilder;
}
#endregion
#region IColumnBuilder Members
public IGridBuilder<TModel> GridBuilderReference { get; private set; }
public string CssClass { get; private set; }
public IColumnBuilder<TModel> Bind<TItem>(Expression<Func<TModel, TItem>> propertySelector)
{
// Reset the properties. This is needed because they are not cleared automatticly. It's not a new instance which is created.
CssClass = null;
GridBuilderReference.ColumnBuilders.Add(this);
return this;
}
public IColumnBuilder<TModel> WithCss(string className)
{
CssClass = className;
return this;
}
#endregion
}
公共类ColumnBuilder:IColumnBuilder
{
#区域构造函数
公共ColumnBuilder(IGridBuilder gridBuilder)
{
GridBuilderReference=gridBuilder;
}
#端区
#区域IColumnBuilder成员
公共IGridBuilder GridBuilderReference{get;private set;}
公共字符串CssClass{get;private set;}
公共IColumnBuilder绑定(表达式属性选择器)
{
//重置属性。这是必需的,因为它们不是自动清除的。它不是创建的新实例。
CssClass=null;
GridBuilderReference.ColumnBuilders.Add(此);
归还这个;
}
带有CSS的公共IColumnBuilder(字符串类名称)
{
CssClass=className;
归还这个;
}
#端区
}
首先,这是我的第一个流畅的界面实现,所以如果这不是一个好方法,请告诉我正确的方向
情况:
- 当我构建网格时,我传递了一个绑定列的动作,这些列也很流畅(例如,我可以在列上添加一个类)。现在,为了渲染这些,我认为在我的IGridBuilder中保存对所有IColumnBuilder实例的引用是一个好主意,这样在我的GridBuilder渲染方法中,我可以执行如下操作 //在列之前进行渲染 foreach(菌落中的c型变种) { c、 Render(); } //在列之后进行渲染
但这有一个奇怪的行为(例如,包含ColumnBuilder的列表确实与上次执行的ColumnBuilder的属性匹配)。方法1
public class ColumnBuilderFactory<TModel> : IColumnBuilderFactory<TModel>
{
#region Constructors
public ColumnBuilderFactory(IGridBuilder<TModel> gridBuilder)
{
gridBuilderReference = gridBuilder;
}
#endregion
#region IColumnBuilderFactory Members
private IGridBuilder<TModel> gridBuilderReference { get; private set; }
internal IList<IColumnBuilder<TModel>> Columns {get; private set; }
public IColumnBuilder<TModel> New()
{
var column = new ColumnBuilder(gridBuilderReference);
Columns.Add(column);
return column;
}
#endregion
}
这是有用法的
RenderedOutput = HtmlHelper.GridFor(Model)
.WithColumns(columnFactory =>
{
columnFactory.New().Bind(x => x.Name)
.WithCss("inline");
columnFactory.New().Bind(x => x.Age)
.WithCss("inline fixed right");
})
.Render();
方法2
另一种方法通过欺骗和忽略这一点(使用FluentAPI替换它)实现了大致相同的效果,基本上它与您当前的用法相同,但是Bind
变得
public IGridBuilder<TModel> WithColumns(Action<IColumnBuilderFactory<TModel>> bindAllColumns)
{
var factory = new ColumnBuilderFactory<TModel>(this);
bindAllColumns(factory);
foreach(var column in factory)
{
this.ColumnBuilders.Add(column );
}
return this;
}
public IColumnBuilder<TModel> Bind<TItem>(Expression<Func<TModel, TItem>> propertySelector)
{
var builder = new ColumnBuilder<TModel>(GridBuilderReference);
GridBuilderReference.ColumnBuilders.Add(builder);
return builder;
}
显示方法2的控制台应用程序示例
using System;
using System.Collections.Generic;
using System.Linq.Expressions;
namespace ConsoleApplication3
{
class Program
{
static void Main(string[] args)
{
var master = FluentHelper.GridFor(new Model())
.WithColumns(column =>
{
column.Bind(x => x.Name)
.WithCSS("inline");
column.Bind(x => x.Age)
.WithCSS("inline fixed right");
});
foreach(var c in master.children)
{
Console.WriteLine(c.Binding.ToString());
Console.WriteLine(c.CSS);
}
Console.ReadKey(true);
}
}
class Model
{
public string Name { get; set; }
public string Age { get; set; }
}
class GridBuilder<T>
{
public GridBuilder<T> WithColumns(Action<ColumnBuilder<T>> bindAllColumns)
{
bindAllColumns(new ColumnBuilder<T>(this));
return this;
}
public List<ColumnBuilder<T>> children = new List<ColumnBuilder<T>>();
}
class ColumnBuilder<T>
{
private GridBuilder<T> grid;
public string Binding;
public string CSS;
public ColumnBuilder(GridBuilder<T> grid)
{
// TODO: Complete member initialization
this.grid = grid;
}
public void WithCSS(string css)
{
this.CSS = css;
}
public ColumnBuilder<T> Bind<TItem>(Expression<Func<T, TItem>> propertySelector)
{
var builder = new ColumnBuilder<T>(grid);
builder.Binding = (propertySelector.Body as MemberExpression).Member.Name;
grid.children.Add(builder);
return builder;
}
}
static class FluentHelper
{
internal static GridBuilder<T> GridFor<T>(T model)
{
return new GridBuilder<T>();
}
}
}
使用系统;
使用System.Collections.Generic;
使用System.Linq.Expressions;
命名空间控制台应用程序3
{
班级计划
{
静态void Main(字符串[]参数)
{
var master=FluentHelper.GridFor(新模型())
.WithColumns(列=>
{
column.Bind(x=>x.Name)
.WithCSS(“内联”);
column.Bind(x=>x.Age)
.WithCSS(“内联固定权利”);
});
foreach(主辅变量c)
{
Console.WriteLine(c.Binding.ToString());
Console.WriteLine(c.CSS);
}
Console.ReadKey(true);
}
}
类模型
{
公共字符串名称{get;set;}
公共字符串年龄{get;set;}
}
类网格生成器
{
带列的公共GridBuilder(操作bindAllColumns)
{
bindAllColumns(新ColumnBuilder(this));
归还这个;
}
public List children=new List();
}
类列生成器
{
私有网格生成器网格;
公共字符串绑定;
公共字符串CSS;
公共列生成器(GridBuilder网格)
{
//TODO:完成成员初始化
using System;
using System.Collections.Generic;
using System.Linq.Expressions;
namespace ConsoleApplication3
{
class Program
{
static void Main(string[] args)
{
var master = FluentHelper.GridFor(new Model())
.WithColumns(column =>
{
column.Bind(x => x.Name)
.WithCSS("inline");
column.Bind(x => x.Age)
.WithCSS("inline fixed right");
});
foreach(var c in master.children)
{
Console.WriteLine(c.Binding.ToString());
Console.WriteLine(c.CSS);
}
Console.ReadKey(true);
}
}
class Model
{
public string Name { get; set; }
public string Age { get; set; }
}
class GridBuilder<T>
{
public GridBuilder<T> WithColumns(Action<ColumnBuilder<T>> bindAllColumns)
{
bindAllColumns(new ColumnBuilder<T>(this));
return this;
}
public List<ColumnBuilder<T>> children = new List<ColumnBuilder<T>>();
}
class ColumnBuilder<T>
{
private GridBuilder<T> grid;
public string Binding;
public string CSS;
public ColumnBuilder(GridBuilder<T> grid)
{
// TODO: Complete member initialization
this.grid = grid;
}
public void WithCSS(string css)
{
this.CSS = css;
}
public ColumnBuilder<T> Bind<TItem>(Expression<Func<T, TItem>> propertySelector)
{
var builder = new ColumnBuilder<T>(grid);
builder.Binding = (propertySelector.Body as MemberExpression).Member.Name;
grid.children.Add(builder);
return builder;
}
}
static class FluentHelper
{
internal static GridBuilder<T> GridFor<T>(T model)
{
return new GridBuilder<T>();
}
}
}