/// <summary>
/// 遍历绑定所有子元素
/// </summary>
/// <param name="element">要绑定子元素的元素</param>
private void BindChilds(IHtmlElement element)
{
foreach (var child in element.Elements().ToArray())
{
BindElement(child);
}
}
/// <summary>
/// 对元素进行数据绑定
/// </summary>
/// <param name="element">要进行数据绑定的元素</param>
protected virtual void DataBind(IHtmlElement element, BindingContext context)
{
var bindings = FindBindings(element).OrderBy(b => b.Priority);
context.Enter(element);
bindings.ForAll(b => b.DataBind(context));
element.Elements().ForAll(e => DataBind(e, context));
context.Exit(element);
}
public HtmlList( IHtmlElement element )
{
if ( element == null )
throw new ArgumentNullException( "element" );
if ( !HtmlSpecification.listElements.Contains( element.Name.ToLowerInvariant() ) )
throw new ArgumentException( "只能从列表元素创建 HtmlList 对象" );
if ( element.Elements().Any( e => !e.Name.EqualsIgnoreCase( "li" ) ) )
throw new FormatException( "HTML 文档格式不正确，列表元素只能包含 li 元素" );
if ( element.Nodes().OfType<IHtmlTextNode>().Any( n => !n.IsWhiteSpace() ) )
throw new FormatException( "HTML 文档格式不正确，列表元素只能包含 li 元素，不能包含文本。" );
_element = element;
}
/*
* /// <summary>
* /// 设置元素的InnerHTML
* /// </summary>
* /// <param name="element">要设置InnerHTML的元素</param>
* /// <param name="html">要设置的HTML文本</param>
* /// <exception cref="System.InvalidOperationException">如果元素不能被安全的修改内容</exception>
* public static void InnerHtml( this IHtmlElement element, string html )
* {
*
* if ( element == null )
* throw new ArgumentNullException( "element" );
*
* lock ( element.SyncRoot )
* {
* if ( !IsSafeBindable( element ) )
* throw new InvalidOperationException( "不能对元素设置InnerHTML，因为该元素不能被安全的修改内容。如果确信要改变HTML文档结构，请使用ReplaceChildsWithHtml扩展方法。" );
*
* ReplaceChildsWithHtml( element, html );
* }
* }
*
*
* /// <summary>
* /// 将元素内容替换为指定文本
* /// </summary>
* /// <param name="element">要替换的文本</param>
* /// <param name="text">要设置的文本</param>
* /// <exception cref="System.InvalidOperationException">如果元素不能被安全的修改内容</exception>
* public static void InnerText( this IHtmlElement element, string text )
* {
*
* if ( element == null )
* throw new ArgumentNullException( "element" );
*
* lock ( element.SyncRoot )
* {
* if ( !IsSafeBindable( element ) )
* throw new InvalidOperationException( "不能对元素设置InnerText，因为该元素不能被安全的修改内容。如果确信要改变HTML文档结构，请使用ReplaceChildsWithText扩展方法。" );
*
* ReplaceChildsWithText( element, text );
* }
* }
*/
/// <summary>
/// 内部方法，用于确定一个元素的内容是否可以安全数据绑定（不破坏文档结构）。
/// </summary>
/// <param name="element">要判断的元素</param>
/// <returns></returns>
internal static bool IsSafeBindable(this IHtmlElement element)
{
lock (element.SyncRoot)
{
var specification = element.Document.HtmlSpecification;
if (element.Nodes().All(n => n is IHtmlTextNode || n is IHtmlComment))//只有文本和注释的元素是可以被安全数据绑定的。
{
return(true);
}
if (!element.Nodes().All(n => n is IHtmlTextNode || n is IHtmlComment || n is IHtmlElement))//内容只能由文本、注释和元素三者组成
{
return(false);
}
var childs = element.Elements();
//如果有任何一个子元素有ID属性，那么它是不安全的
if (childs.Any(e => e.Attribute("id").Value() != null))
{
return(false);
}
//如果有任何一个子元素是不安全的，那么它是不安全的
if (childs.Any(e => e.IsSafeBindable() == false))
{
return(false);
}
//如果元素内部只有设置文本样式的子元素，那么它是安全的。
if (childs.All(e => specification.IsStylingElement(e) || specification.IsPhraseElement(e)))
{
return(true);
}
return(false);
}
}
private List <string> ReadLines(IHtmlElement elem)
{
List <string> list = new List <string>();
var elements = elem.Elements();
if (!elements.Any() || elem.Name == "p" || elem.Name == "div" || elem.Name == "a")
{
try
{
var text = elem.InnerText();
if (string.IsNullOrEmpty(text))
{
list.Add("");
}
else
{
list.Add(text);
}
}
catch
{
}
}
else if (elem.Name == "br" || elem.Name == "hr")
{
}
else
{
foreach (var item in elements)
{
if (item.Name != "style" && item.Name != "script")
{
list.AddRange(ReadLines(item));
}
}
}
return(list);
}
bool ICssPseudoClassSelector.IsEligible(IHtmlElement element)
{
if (element == null)
{
throw new ArgumentNullException("element");
}
switch (_name)
{
case "only-child":
return(element.Siblings().Count() == 1);
case "only-of-type":
return(element.Siblings(element.Name).Count() == 1);
case "empty":
return(element.Elements().Count() == 0);
default:
throw new InvalidOperationException();
}
}
/// <summary>
/// 合并内容视图与母板视图的文档头
/// </summary>
/// <param name="masterHead">母板视图的文档头</param>
/// <param name="contentHead">内容视图的文档头</param>
/// <returns>合并后的 <head> 元素</returns>
protected virtual IHtmlElement MergeHead(IHtmlElement masterHead, IHtmlElement contentHead)
{
var head = masterHead.Document.CreateFragment().AddElement("head");
head.AddCopy(contentHead.Elements().Where(e => e.Attribute("ignore") == null));
if (!head.Find("title").Any())
{
var title = masterHead.Find("title").FirstOrDefault();
head.AddCopy(title);
}
{
var existsStyleSheets = new HashSet <string>(head.Find("link[rel=stylesheet]").Select(e => e.Attribute("href").Value()), StringComparer.OrdinalIgnoreCase);
foreach (var element in masterHead.Find("link[rel=stylesheet]"))
{
if (!existsStyleSheets.Contains(element.Attribute("href").Value()))
{
head.AddCopy(element);
}
}
}
{
var existsScripts = new HashSet <string>(head.Find("script[src]").Select(e => e.Attribute("src").Value()), StringComparer.OrdinalIgnoreCase);
foreach (var element in masterHead.Find("script[src]"))
{
if (!existsScripts.Contains(element.Attribute("src").Value()))
{
head.AddCopy(element);
}
}
}
return(head);
}
public HtmlList(IHtmlElement element)
{
if (element == null)
{
throw new ArgumentNullException("element");
}
if (!HtmlSpecification.listElements.Contains(element.Name.ToLowerInvariant()))
{
throw new ArgumentException("只能从列表元素创建 HtmlList 对象");
}
if (element.Elements().Any(e => !e.Name.EqualsIgnoreCase("li")))
{
throw new FormatException("HTML 文档格式不正确，列表元素只能包含 li 元素");
}
if (element.Nodes().OfType <IHtmlTextNode>().Any(n => !n.IsWhiteSpace()))
{
throw new FormatException("HTML 文档格式不正确，列表元素只能包含 li 元素，不能包含文本。");
}
_element = element;
}
/// <summary>
/// 合并内容视图与母板视图的文档头
/// </summary>
/// <param name="masterHead">母板视图的文档头</param>
/// <param name="contentHead">内容视图的文档头</param>
/// <returns>合并后的 <head> 元素</returns>
protected virtual IHtmlElement MergeHead( IHtmlElement masterHead, IHtmlElement contentHead )
{
var head = masterHead.Document.CreateFragment().AddElement( "head" );
head.AddCopy( contentHead.Elements().Where( e => e.Attribute( "ignore" ) == null ) );
if ( !head.Find( "title" ).Any() )
{
var title = masterHead.Find( "title" ).FirstOrDefault();
head.AddCopy( title );
}
{
var existsStyleSheets = new HashSet<string>( head.Find( "link[rel=stylesheet]" ).Select( e => e.Attribute( "href" ).Value() ), StringComparer.OrdinalIgnoreCase );
foreach ( var element in masterHead.Find( "link[rel=stylesheet]" ) )
{
if ( !existsStyleSheets.Contains( element.Attribute( "href" ).Value() ) )
head.AddCopy( element );
}
}
{
var existsScripts = new HashSet<string>( head.Find( "script[src]" ).Select( e => e.Attribute( "src" ).Value() ), StringComparer.OrdinalIgnoreCase );
foreach ( var element in masterHead.Find( "script[src]" ) )
{
if ( !existsScripts.Contains( element.Attribute( "src" ).Value() ) )
head.AddCopy( element );
}
}
return head;
}
/// <summary>
/// 对元素进行数据绑定
/// </summary>
/// <param name="element">要进行数据绑定的元素</param>
protected virtual void DataBind( IHtmlElement element, BindingContext context )
{
var bindings = FindBindings( element ).OrderBy( b => b.Priority );
context.Enter( element );
bindings.ForAll( b => b.DataBind( context ) );
element.Elements().ForAll( e => DataBind( e, context ) );
context.Exit( element );
}
/// <summary>
/// 遍历绑定所有子元素
/// </summary>
/// <param name="element">要绑定子元素的元素</param>
private void BindChilds( IHtmlElement element )
{
foreach ( var child in element.Elements().ToArray() )
BindElement( child );
}
