MVC4 extension methods

1. Extension Code Institutions

namespacesystem.web.mvc.html{ Public Static classFormExtensions//form-related extension methods, such as creating form labels, and so on.      Public Static classInputExtensions//all input is included here, for example: Text,button,readiobutton and so on.      Public Static classLinkextensions//Link Related methods     Public classMvcform:idisposable//independent of client controls     Public Static classRenderPartialExtensions//This is the output Partialview     Public Static classSelectextensions//output drop-down box     Public Static classTextAreaExtensions//output multi-line text box     Public Static classValidationExtensions//output related FORM element validation. }

2. Tagbuilder structure

    //Methods     PublicTagbuilder (stringtagName);  Public voidaddCssClass (stringValue);//Add Style     Public voidGenerateid (stringname);//set the control ID    Private stringgetattributesstring ();  Public voidMergeattribute (stringKeystringValue);//Setting property values     Public voidMergeattribute (stringKeystringValueBOOLreplaceexisting);  Public voidMergeattributes<tkey, Tvalue> (Idictionary<tkey, tvalue>attributes);  Public voidMergeattributes<tkey, Tvalue> (Idictionary<tkey, tvalue> attributes,BOOLreplaceexisting);  Public voidSetinnertext (stringInnerText);//Set display text     Public Override stringToString ();  Public stringToString (Tagrendermode rendermode);//Output Control HTML

3. Example: Html.image (...)

 Public Static classimagehelper{ Public Static stringImage ( ThisHtmlHelper Helper,stringIdstringUrlstringAlternateText) {            returnImage (helper, id, url, alternatetext,NULL); }         Public Static stringImage ( ThisHtmlHelper Helper,stringIdstringUrlstringAlternateText,Objecthtmlattributes) {            //Create an IMG tag            varBuilder =NewTagbuilder ("img"); //Add id attributeBuilder.            Generateid (ID); //Add PropertyBuilder. Mergeattribute ("src", URL); Builder. Mergeattribute ("alt", AlternateText); Builder. Mergeattributes (Newroutevaluedictionary (htmlattributes)); //output the full img tag            return builder.        ToString (tagrendermode.selfclosing); }}