postthreaded.cs

微软的.NET论坛的源代码（COOL!!!）

using System;
using System.Collections;
using System.Collections.Specialized;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using AspNetForums;
using AspNetForums.Components;
using System.ComponentModel;

namespace AspNetForums.Controls {

    /// <summary>
    /// This Web control displays a thread in a threaded display.  The developer may pass in
    /// either a PostID or a ThreadID.  If a PostID is passed in, the thread that that Post belongs
    /// to is constructed.
    /// </summary>
    [
    ParseChildren(true)
    ]
    public class PostThreaded : WebControl, INamingContainer {

        // Class constants
        const String defaultPostDateTimeFormat = "ddd MMM dd, yyyy hh:mm tt";

        // Member variable used to display threads
        Repeater threadedRepeater;
        ITemplate threadItemTemplate;
        ITemplate threadBelowThreshHoldItemTemplate;
        ITemplate bodyTemplate;

        // Member variables used to keep track of where we are in the thread
        int threadedStartPostLevel = 1;
        int threshHold = 1;
        User postUser;

        // *********************************************************************
        //  ThreadView
        //
        /// <summary>
        /// Class constructor. We'll attempt to get the PostID or ThreadID
        /// </summary>
        /// 
        // ********************************************************************/
        public PostThreaded() {

            // If we have an instance of context, let's attempt to
            // get the PostID so we can save the user from writing
            // the code
            try {
                if (null != Context.Request.QueryString["PostID"]) {
                    string postID = Context.Request.QueryString["PostID"];

                    // Contains a #
                    if (postID.IndexOf("#") > 0)
                        postID = postID.Substring(0, postID.IndexOf("#"));

                    this.PostID = Convert.ToInt32(postID);
                } else if (null != Context.Request.Form["PostId"]) {
                    this.PostID = Convert.ToInt32(Context.Request.Form["PostID"]);
                }
            } catch (Exception e) {
                HttpContext.Current.Response.Redirect(Globals.UrlMessage + Convert.ToInt32(Messages.PostDoesNotExist));
                HttpContext.Current.Response.End();
            }

        }


        // *********************************************************************
        //  BuildItemTemplate
        //
        /// <summary>
        /// Used to create the ItemTemplate value if a template is not provided.
        /// </summary>
        /// 
        // ********************************************************************/
        private void BuildItemTemplate(Control _ctrl) {

            System.Web.UI.IParserAccessor __parser = ((System.Web.UI.IParserAccessor)(_ctrl));
            __parser.AddParsedSubObject(RenderItemTemplate());
            
        }

        // *********************************************************************
        //  RenderItemTemplate
        //
        /// <summary>
        /// Creates, DataBinds, and returns a table Control. This table control
        /// is where the body of the thread is injected. We DataBind the table since
        /// multiple rows may be added depending on the format chosen.
        /// </summary>
        /// 
        // ********************************************************************/
        private Control RenderItemTemplate() {

            Table table = new Table();

            table.CellPadding = 2;
            table.CellSpacing = 0;
            table.Width = Unit.Percentage(100);
            table.DataBinding += new System.EventHandler(DataBindThread);

            return table;
        }

        // *********************************************************************
        //  DataBindThread
        //
        /// <summary>
        /// Performs the DataBinding for each thread item bound to the repeater.
        /// </summary>
        /// 
        // ********************************************************************/
        private void DataBindThread(Object sender, EventArgs e) {
            Table table;
            TableRow tr;
            TableCell td;
            RepeaterItem container;
            Post post;
            bool isBelowThreshHold = false;
            bool isFirstPost = false;

            // Get the table instance we databound
            table = (Table) sender;
            
            // Get the data item to be bound to
            container = (RepeaterItem) table.NamingContainer;

            // Extract the original databound class type
            post = (Post) container.DataItem;

            // If we're the first item, set the threadedStartPostLevel.
            // This private member variable determines what nesting level
            // to start at.
            if (container.ItemIndex == 0) {
                threadedStartPostLevel = post.PostLevel;
                isFirstPost = true;
            }

            // Determine if we are below the threshold of threads to display
            // with body.
            if ((post.PostLevel - threadedStartPostLevel) > Threshhold)
                isBelowThreshHold = true;

            // This whitespace is used to separate thread items
            if ((!isBelowThreshHold) && (!isFirstPost)) {
                // Add some white space
                tr = new TableRow();
                td = new TableCell();
                td.ColumnSpan = 2;
                td.Height = Unit.Pixel(12);
                tr.Controls.Add(td);
                table.Controls.Add(tr);
            }

            // Prepare to display the thread
            tr = new TableRow();

            // If we're not the first post, indent
            if (!isFirstPost) {
                // Indenting
                td = new TableCell();
                td.Wrap = false;
                td.VerticalAlign = VerticalAlign.Top;
                Label indent = new Label();
                indent.CssClass = "normalTextSmallBold";
                indent.DataBinding += new System.EventHandler(HandleIndentingForThreaded);
                td.Controls.Add(indent);
                tr.Controls.Add(td);
            }

            // Databind this cell for the actual thread display
            td = new TableCell();
            td.DataBinding += new System.EventHandler(HandleDataBindingForThreadTitle);

            if (isFirstPost) {
                td.ColumnSpan = 2;
            } else {
                td.Width = Unit.Percentage(100);
            }

            tr.Controls.Add(td);
            table.Controls.Add(tr);

            // Display body of post
            if (!isBelowThreshHold) {
                td = new TableCell();
                tr = new TableRow();

                // Set some properties on the row
                td.CssClass = "forumRow";

                // If we're not the first item, let's add a bit of whitespace
                if (isFirstPost) {
                    td.ColumnSpan = 2;
                } else {
                    tr.Controls.Add(new TableCell());
                }

                // Template?
                if (null != this.BodyTemplate) {

                    BodyTemplate.InstantiateIn(td);
                    tr.Controls.Add(td);
                    table.Controls.Add(tr);
                    return;
                }

                Label body = new Label();

                // Set up the body text
                body.CssClass = "normalTextSmall";
                body.Text = Globals.FormatPostBody(post.Body);

                postUser = Users.GetUserInfo(post.Username, false);

                if (postUser.Signature != "") {
                    body.Text += Globals.FormatSignature(postUser.Signature);
                }


                // Add the body to the cell
                td.Controls.Add(body);

                tr.Controls.Add(td);
                table.Controls.Add(tr);

            }

        }

        // *********************************************************************
        //  HandleDataBindingForThreadDisplay
        //
        /// <summary>
        /// Perform databinding and control the display of a given thread.
        /// </summary>
        /// 
        // ********************************************************************/
        private void HandleDataBindingForThreadTitle (Object sender, EventArgs e) {
            TableCell td;
            RepeaterItem container;
            Post post;
            bool isBelowThreshHold = false;

            // Bound to type TableCell
            td = (TableCell) sender;

            // Get the repeater item containing the bound data
            container = (RepeaterItem) td.NamingContainer;

            // Get the original class type we're bound to
            post = (Post) container.DataItem;

            // Determine if we are below the threshold of threads to display
            // with body.
            if ((post.PostLevel - threadedStartPostLevel) > Threshhold)
                isBelowThreshHold = true;

            // Format differently based on the threshold to view nested posts
            if (isBelowThreshHold) {

                // Do we have a template
                if (this.ThreadBelowThreshHoldItemTemplate != null){
                    ThreadBelowThreshHoldItemTemplate.InstantiateIn(td);
                    return;
                }

                // Label for display
                Label label = new Label();

                // Add bullet
                LiteralControl bullet = new LiteralControl();
                bullet.Text = "<img src=\"" + Globals.ApplicationVRoot + "/skins/" + Globals.Skin + "/images/node.gif" + "\">";
                label.Controls.Add(bullet);

                // Subject
                HyperLink subject = new HyperLink();
                subject.Text = post.Subject;
                subject.CssClass = "linkSmallBold";
                subject.NavigateUrl = Globals.UrlShowPost + post.PostID + "&View=Threaded&ThreshHold=" + (Convert.ToInt32(post.PostLevel) + 1) + "#" + post.PostID;
                label.Controls.Add(subject);

                // Whitespace
                label.Controls.Add(new LiteralControl(" "));

                // Author
                HyperLink author = new HyperLink();
                author.CssClass = "linkSmallBold";
                author.Text = post.Username;
                author.NavigateUrl = Globals.UrlUserProfile + post.Username;
                label.Controls.Add(author);

                // Whitespace
                label.Controls.Add(new LiteralControl(" "));
            
                // Special formatting for the date
                Label datePosted = new Label();
                datePosted.CssClass = "normalTextSmall";
                if (Page.Request.IsAuthenticated) {
                    datePosted.Text = Users.AdjustForTimezone(post.PostDate, ((User) Users.GetUserInfo(Context.User.Identity.Name, true)).Timezone, PostDateTimeFormat);
                } else {
                    datePosted.Text = "Posted: " + post.PostDate.ToString(PostDateTimeFormat);
                }
                label.Controls.Add(datePosted);

                td.Controls.Add(label);

            } else {
                // Set the style on the cell we render in
                td.CssClass = "threadTitle";
                td.Controls.Add(RenderDetailedThreadTitle(post));

            }

        }

        // *********************************************************************
        //  RenderDetailedThreadTitle
        //
        /// <summary>
        /// Renders the thread title used when a thread body is displayed
        /// </summary>
        /// 
        // ********************************************************************/
        private Control RenderDetailedThreadTitle(Post post) {
            Table table;
            TableRow tr;
            TableCell td;
            Image image;
            
            // Create the table
            table = new Table();
            table.CellPadding = 0;
            table.CellSpacing = 2;

            // Get the user that created the post
            postUser = Users.GetUserInfo(post.Username, false);

            // Create the row
            tr = new TableRow();