HttpModule - 获取HTML内容或控件以进行修改

Question

试过这样的事情:

HttpApplication app = s as HttpApplication; //s is sender of the OnBeginRequest event
System.Web.UI.Page p = (System.Web.UI.Page)app.Context.Handler;
System.Web.UI.WebControls.Label lbl = new System.Web.UI.WebControls.Label();
lbl.Text = "TEST TEST TEST";
p.Controls.Add(lbl);    

运行时,我得到"对象引用未设置为对象的实例".为最后一行......

如何在原始文件中的特定loactions处插入两行文本(asp.net/html)？我怎么弄清楚文件的扩展名(我只想在aspx文件上应用这个...？

Answer 1

它比你想象的简单:

    public void Init(HttpApplication app)
    {
        app.PreRequestHandlerExecute += OnPreRequestHandlerExecute;
    }

    private void OnPreRequestHandlerExecute(object sender, EventArgs args)
    {
        HttpApplication app = sender as HttpApplication;
        if (app != null)
        {
            Page page = app.Context.Handler as Page;
            if (page != null)
            {
                page.PreRender += OnPreRender;
            }
        }
    }

    private void OnPreRender(object sender, EventArgs args)
    {
        Page page = sender as Page;
        if (page != null)
        {
            page.Controls.Clear(); // Or do whatever u want with ur page...
        }
    }

如果PreRender事件不够,你可以在PreRequestHandlerExecute EventHandler中添加你需要的任何事件......