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POAsp.Net Music Player
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  1. POAsp.Net Music Player
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    copied!<p>I was following a guide to create a simple music directory.</p> <p>It reads from a folder and put the music names on a grid, then add a "play button" on grid that should send the file to a player.</p> <p>here is the code behind:</p> <pre><code>using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.Web.UI; using System.Web.UI.WebControls; using System.Data; using System.IO; using System.Text; namespace WebApplication8 { public partial class MusicPlayer : System.Web.UI.Page { public string mySrc; protected void Page_Load(object sender, EventArgs e) { if (!IsPostBack) { getSongName(); } } public void getSongName() { DirectoryInfo di = new DirectoryInfo("your music directory here"); if (di.Exists == true) { DataTable dt = new DataTable(); dt.Columns.Add("SongName"); foreach (FileInfo fi in di.GetFiles("*.mp3", SearchOption.AllDirectories))//get filename from this directory { DataRow dr = dt.NewRow(); dr["SongName"] = fi.Name;//show only song name excluding path dt.Rows.Add(dr); } grid.DataSource = dt; grid.DataBind(); } } protected void grid_RowDataBound(object sender, GridViewRowEventArgs e) { e.Row.Attributes["onmouseover"] = "javascript:setMouseOverColor(this);"; e.Row.Attributes["onmouseout"] = "javascript:setMouseOutColor(this);"; } protected void grid_SelectedIndexChanged(object sender, EventArgs e) { DirectoryInfo di = new DirectoryInfo("your music directory here"); mySrc = di + grid.SelectedDataKey.Values["SongName"].ToString(); } } } </code></pre> <p>and here is the front page code: </p> <pre><code> %@ Page Language="C#" AutoEventWireup="true" CodeBehind="MusicPlayer.aspx.cs" Inherits="WebApplication8.MusicPlayer" %&gt; &lt;!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"&gt; &lt;html xmlns="http://www.w3.org/1999/xhtml"&gt; &lt;head id="Head1" runat="server"&gt; &lt;title&gt;&lt;/title&gt; &lt;script type="text/javascript"&gt; var oldgridSelectedColor; function setMouseOverColor(element) { oldgridSelectedColor = element.style.backgroundColor; element.style.backgroundColor = '#dcdcdc'; element.style.cursor = 'hand'; } function setMouseOutColor(element) { element.style.backgroundColor = oldgridSelectedColor; element.style.textDecoration = 'none'; } &lt;/script&gt; &lt;style type="text/css"&gt; &lt;/style&gt; &lt;/head&gt; &lt;body&gt; &lt;form id="form1" runat="server"&gt; &lt;asp:ScriptManager ID="ScriptManager1" runat="server"&gt; &lt;/asp:ScriptManager&gt; &lt;table&gt; &lt;tr&gt; &lt;td&gt; &lt;asp:UpdatePanel ID="UpdatePanel1" runat="server" UpdateMode="Conditional" ChildrenAsTriggers="False"&gt; &lt;Triggers&gt; &lt;asp:AsyncPostBackTrigger ControlID="grid" EventName="Load"&gt;&lt;/asp:AsyncPostBackTrigger&gt; &lt;/Triggers&gt; &lt;ContentTemplate&gt; &lt;object classid="CLSID:22D6F312-B0F6-11D0-94AB-0080C74C7E95" id="player" class="musicplayer-media"&gt; &lt;param name="url" value="&lt;% =mySrc %&gt;" /&gt; &lt;param name="src" value="&lt;% =mySrc %&gt;" /&gt; &lt;param name="name" value="musicplayer" /&gt; &lt;param name="showcontrols" value="true" /&gt; &lt;param name="animationatStart" value="true" /&gt; &lt;param name="volume" value="0" /&gt; &lt;!--[if !IE]&gt;--&gt; &lt;object type="video/x-ms-wmv" data="&lt;% =mySrc %&gt;" class="musicplayer-media"&gt; &lt;param name="src" value="&lt;% =mySrc %&gt;" /&gt; &lt;param name="name" value="musicplayer" /&gt; &lt;param name="autostart" value="true" /&gt; &lt;param name="controller" value="true" /&gt; &lt;param name="volume" value="0" /&gt; &lt;/object&gt; &lt;!--&lt;![endif]--&gt; &lt;/object&gt; &lt;/ContentTemplate&gt; &lt;/asp:UpdatePanel&gt; &lt;/td&gt; &lt;/tr&gt; &lt;tr&gt; &lt;td&gt; &lt;asp:GridView ID="grid" runat="server" BackColor="#CC9900" ForeColor="#663300" OnRowDataBound="grid_RowDataBound" OnSelectedIndexChanged="grid_SelectedIndexChanged" DataKeyNames="songname"&gt; &lt;Columns&gt; &lt;asp:ButtonField CommandName="Select" Text="Play" /&gt; &lt;/Columns&gt; &lt;SelectedRowStyle BackColor="#66CCFF" BorderColor="Black" BorderStyle="Solid" /&gt; &lt;/asp:GridView&gt; &lt;/td&gt; &lt;/tr&gt; &lt;/table&gt; &lt;/form&gt; &lt;/body&gt; &lt;/html&gt; </code></pre> <p>The issue i'm having is this: I can load the content on a page and show then, but when I click on play button on gridview, it gives me an arror:</p> <pre><code>mySrc = di + grid.SelectedDataKey.Values["SongName"].ToString(); NullReferenceException was unhandled by user code. </code></pre> <p>I can see that mySrc is returning a null value, but when I "look" inside di and grid.selected, there are values in there.</p> <p>Can someone help me with this and tell me what Am I doing wrong?</p> <p>Thanks in advance and sorry about my poor english, its not my native language.</p> <p><strong>Edit:</strong> I found out that on my front page code, the KeyDataName was set as "songname", I changed it to SongName to match the code behind, and now it dont give me an error anymore, but just dont do anything. I click on play and nothing happens.</p> <p>Thanks again.</p>
 

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