[技术散分]Asp.Net表示层方案(借助NVelocity模板引擎)

NqIceCoffee 2009-09-22 10:12:16

由于工作中常常需要使用模板配置文件来做动态的输出

而以前又采用的是Dom解析Xml的方式,导致如果模板中需要一个特殊处理,就得变动代码,以至于现在的不堪重负

不经意的时候,看到了NVelocity模板引擎,感觉很不错,语法很简单,很适合做UI,遂封装了下,现在分享给大家

如果您有任何的建议或者意见,都可以跟帖或者EMail我:NqIceCoffee@163.com

代码不难看懂,直接上代码了:

BaseHandler.cs

using System;

using System.IO;

using System.Web;

using System.Text;

using System.Collections;



using NVelocity;

using NVelocity.App;

using NVelocity.Context;

using NVelocity.Runtime;

using Commons.Collections;



namespace AspNet.App.UI

{

    public abstract class BaseHandler : IHttpHandler

    {

        private static readonly VelocityEngine viewEngine = new VelocityEngine(); 



        static BaseHandler()

        {

            //TODO:这里的硬编码可以改成配置文件的方式

            ExtendedProperties extend = new ExtendedProperties();

            extend.AddProperty(RuntimeConstants.COUNTER_NAME, "i");

            extend.AddProperty(RuntimeConstants.RESOURCE_LOADER, "file");

            extend.AddProperty(RuntimeConstants.INPUT_ENCODING, "utf-8");

            extend.AddProperty(RuntimeConstants.OUTPUT_ENCODING, "utf-8");

            

            string appPath = AppDomain.CurrentDomain.BaseDirectory;

            extend.AddProperty(RuntimeConstants.FILE_RESOURCE_LOADER_PATH, appPath);



            //模板的缓存设置

            extend.AddProperty(RuntimeConstants.FILE_RESOURCE_LOADER_CACHE, true);              //是否缓存

            extend.AddProperty("file.resource.loader.modificationCheckInterval", (Int64)30);    //缓存时间(秒)

            viewEngine.Init(extend);

        }



        public HttpContext HttpContext 

        { 

            get; 

            private set; 

        }



        public HttpRequest Request 

        { 

            get; 

            private set; 

        }



        public HttpResponse Response 

        { 

            get; 

            private set; 

        }



        private Hashtable templateData = new Hashtable();

        public Hashtable TemplateData

        {

            get { return templateData; }

        }



        private string templateFile = string.Empty;

        public string TemplateFile 

        { 

            get { return templateFile; }

            set { templateFile = value; }

        }



        public void ProcessRequest(HttpContext context)

        {

            this.HttpContext = context;

            this.Request = context.Request;

            this.Response = context.Response;



            //此方法主要进行数据的获取

            Handler_Load(this, EventArgs.Empty);



            //输出

            IContext ctx = new VelocityContext(templateData);

            viewEngine.MergeTemplate(TemplateFile, "utf-8", ctx, context.Response.Output);

        }



        //局部文件的呈现

        protected string Merge(Hashtable data, string fileName)

        {

            IContext ctx = new VelocityContext(data);

            StringBuilder sb = new StringBuilder(512);

            StringWriter writer = new StringWriter(sb);



            viewEngine.MergeTemplate(fileName, "utf-8", ctx, writer);

            return sb.ToString();

        }



        public abstract void Handler_Load(object sender, EventArgs e);



        public bool IsReusable

        {

            get { return false; }

        }

    }

}