Flash控件

Flash控件开发

    在做基于asp.net的软件时，似乎Flash不是很常用。但是在电子商务网站中就比较常用了，很多广告或者产品的图片浏览是用Flash的。
    很幸运的是，插入一段Flash的代码并不是很难，但是在习惯于用控件来开发的我们是否会重新接受那种如同asp一样让人眼花的代码。所以，开发一个Flash控件似乎还是比较必要的。当然，我只是简单的开发了一个能用的Flash，更好的功能还要大家去扩展了。好了，闲话不说了，直接进入正题。和其他的asp.net控件一样，Flash控件将继承自WebControl。然后我们只需重写RenderContents方法就可以了。

 [Designer( " Lin.Controls.FlashDesign,Lin.Controls " )]
    [ToolboxData( " <{0}:Flash runat=server></{0}:Flash> " )]
    [ System . Drawing . ToolboxBitmap(typeof(Flash) ,   " Flash.ico " )]
    public class Flash  :  WebControl
    {
        private string imageUrl;

        [UrlProperty ,  Bindable(true) ,  Category( " Behavior " )]
        [DescriptionAttribute( " 链接地址 " )]
        [DefaultValue(null) ,  Editor( " System.Web.UI.Design.XmlUrlEditor, System.Design, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a " ,  typeof(UITypeEditor))]
        public string ImageUrl
        {
            get
            {
                 return  (imageUrl);
            }
            set
            {
                imageUrl  =  value;
            }
        }

        private void RegisterScript()
        {
             if  ( ! this . Page . ClientScript . IsClientScriptIncludeRegistered( " Lin.Controls.myLable " ))
            {
                this . Page . ClientScript . RegisterClientScriptInclude
                (
                     " Lin.Controls.myLable " ,
                    this . Page . ClientScript . GetWebResourceUrl
                    (
                        this . GetType() ,   " Lin.Controls.myLable.js "
                    )
                );
            }
            string str  =  string . Format ( " Rewrite('{0}'); " ,  this . ClientID);
             if  ( ! this . Page . ClientScript . IsStartupScriptRegistered( " flash "   +  this . ClientID))
                this . Page . ClientScript . RegisterStartupScript(this . GetType() ,   " flash "   +  this . ClientID ,  str ,  true);
        }
        protected override void OnPreRender(EventArgs e)
        {
            base . OnPreRender(e);
            this . RegisterScript();
        }

        private string GetUrl(string virtualUrl)
        {
            string applicationPath  =  (HttpRuntime . AppDomainAppVirtualPath . Length   >   1 )  ?  HttpRuntime . AppDomainAppVirtualPath  :  String . Empty;
             if  ( ! string . IsNullOrEmpty(virtualUrl))
            {
                 if  (virtualUrl . StartsWith( " ~/ " ))
                     return  applicationPath  +  virtualUrl . Substring( 1 );
                 else   if  (virtualUrl . StartsWith( " http:// " ))
                     return  virtualUrl;
            }
             return  virtualUrl;
        }

        protected override HtmlTextWriterTag TagKey
        {
            get
            {
                 return  HtmlTextWriterTag . Div;
            }
        }
        protected override void RenderContents(HtmlTextWriter writer)
        {
             if  (this . Height . IsEmpty)
                this . Height  =  new Unit( 100 ,  UnitType . Percentage);
             if  (this . Width . IsEmpty)
                this . Width  =  new Unit( 100 ,  UnitType . Percentage);

            base . RenderContents(writer);
            writer . AddAttribute( " classid " ,   " clsid:D27CDB6E-AE6D-11cf-96B8-444553540000 " );
            writer . AddAttribute( " codebase " ,   " http://linjianyu.cnblogs.com " );
            writer . AddAttribute(HtmlTextWriterAttribute . Width ,  this . Width . ToString());
            writer . AddAttribute(HtmlTextWriterAttribute . Height ,  this . Height . ToString());
            writer . RenderBeginTag(HtmlTextWriterTag . Object);

            writer . AddAttribute(HtmlTextWriterAttribute . Name ,   " movie " );
            writer . AddAttribute(HtmlTextWriterAttribute . Value ,  this . GetUrl(this . ImageUrl));
            writer . RenderBeginTag(HtmlTextWriterTag . Param);
            writer . RenderEndTag();

            writer . AddAttribute(HtmlTextWriterAttribute . Name ,   " quality " );
            writer . AddAttribute(HtmlTextWriterAttribute . Value ,   " high " );
            writer . RenderBeginTag(HtmlTextWriterTag . Param);
            writer . RenderEndTag();

            writer . AddAttribute(HtmlTextWriterAttribute . Src ,  this . GetUrl(this . ImageUrl));
            writer . AddAttribute( " quality " ,   " high " );
            writer . AddAttribute(HtmlTextWriterAttribute . Type ,   " application/x-shockwave-flash " );
            writer . AddAttribute(HtmlTextWriterAttribute . Width ,  this . Width . ToString());
            writer . AddAttribute(HtmlTextWriterAttribute . Height ,  this . Height . ToString());
            writer . RenderBeginTag(HtmlTextWriterTag . Embed);
            writer . RenderEndTag();

            writer . RenderEndTag();
        }

    }

 

 

然后我们为这个控件做一个设计时支持FlashDesign。FlashDesign继承自System.Web.UI.Design.ControlDesigner
支持asp.net设计时控件都应继承自这个类。然后我们override方法GetDesignTimeHtml就可以了。