Get Title,Description and Keywords Meta tags from URL in asp.net using C#, VB.Net

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Introduction: In previous articles i explained How to get current page URL/Address in asp.net and How to Count and display remaining characters in the multiline textbox in asp.net and How to show Validation guidelines in web forms using JavaScript in Asp.net and How to implement JavaScript validation in asp.net website and Convert Rupees,Currency or Numbers to Words and Get age in years,months,days,hours and seconds from DOB and WCF Service to bind,insert,edit,update,delete from sql server database in asp.net and How to Validate and upload image files in asp.net.

In this article I am going to explain with example How to get/read/fetch/retrieve Meta Tags e.g. Title,Description and Keywords from the Web URL or page URL.

Implementation: Just follow the following steps:

Step 1: First you need to add a namespace HtmlAgilityPack in your website project. You can download this from the link http://htmlagilitypack.codeplex.com.

Step 2: Just open the link in browser and click on the purple download button. It will download the zipped folder HtmlAgilityPack.1.4.6( Note: Version may be changed).

Step 3: Extract the folder.  You will see a list of folders there. Choose appropriate folder e.g. if you are using .Net framework 4.0 i.e. Visual studio 2010 then open the folder Net40 and copy the HtmlAgilityPack.dll file from it and paste in the Bin folder of your website in solution explorer. If there is no Bin folder there, then right click on the website name in solution explorer and click on Add ->Add ASP.NET folder -> select Bin and paste the HtmlAgilityPack.dll file in this folder.

Similarly for .Net framework 4.5 i.e. Visual studio 2012 open the folder Net45 and follow the same procedure as mention for Net framework 4.0

Step 4: In the design page (.aspx) place 4 Textbox controls and a Button control. Also place RequiredFieldValidator validation control to force the user to enter the URL in the Enter URL TextBox and RegularExpressionValidator validation control on the page to force user to enter the URL in the correct format e.g. http://www.webcodeexpert.com/

• If you don’t know much about RequiredFieldValidator validation control then read my article How to use RequiredFieldValidator validation control with example in asp.net
• If you don’t know much about RegularExpressionValidator validation control then read my article  How to use RegularExpressionValidator validation control with example in asp.net

Source Code:

<fieldset style="width:450px;">

            <legend>Get Title, Description and Keywords Meta tags from URL in asp.net</legend>

            <table>

                <tr>

                    <td>Enter URL: </td>          

                          <td><asp:TextBox ID="txtUrl" runat="server" Width="250px"></asp:TextBox>

                        <asp:Button ID="btnFetchMetaTags" runat="server"  Text="Fetch MetaTags" OnClick="btnFetchMetaTags_Click" /><br />

                              <asp:RequiredFieldValidator ID="rfvWebUrl" runat="server" ControlToValidate="txtUrl" ErrorMessage="URL can not be left blank" SetFocusOnError="true"></asp:RequiredFieldValidator>

                              <asp:RegularExpressionValidator ID="rgeWebUrl" runat="server" ErrorMessage="Enter the URL in the valid format e.g. http://www.webcodeexpert.com/" ControlToValidate="txtUrl" ForeColor="#FF3300" SetFocusOnError="True" ValidationExpression="http(s)?://([\w-]+\.)+[\w-]+(/[\w- ./?%&amp;=]*)?" Display="Dynamic"></asp:RegularExpressionValidator>

                    </td>

                </tr>

                <tr>

                    <td>Title: </td>

                    <td><asp:TextBox ID="txtTitle" runat="server" Height="41px" TextMode="MultiLine" Width="380px"></asp:TextBox></td>

                </tr>

                <tr>

                    <td>Description: </td>

                    <td><asp:TextBox ID="txtDesc" runat="server" Height="95px" TextMode="MultiLine" Width="380px"></asp:TextBox></td>

                </tr>

                <tr>

                    <td>Keywords: </td>

                    <td><asp:TextBox ID="txtKeywords" runat="server" Height="95px" TextMode="MultiLine" Width="380px"></asp:TextBox></td>

                </tr>

            </table>

        </fieldset>

Step 5: Now we need to write the following code to get the meta tag information

C#.Net Code to get Meta Description of URL

Include the following name spaces:

using System.Net;

 using System.Text.RegularExpressions;

using HtmlAgilityPack;

and write the code on click event of Fetch MetaTags button as:

protected void btnFetchMetaTags_Click(object sender, EventArgs e)

    {

        String strUrl = txtUrl.Text;

        try

        {

            //To Get Title

            WebClient x = new WebClient();

            string pageSource = x.DownloadString(strUrl);

            txtTitle.Text = Regex.Match(pageSource, @"\<title\b[^>]*\>\s*(?<Title>[\s\S]*?)\</title\>", RegexOptions.IgnoreCase).Groups["Title"].Value;

            //Creating a method to get Meta Tags like description and keyword meta tags

            GetMetaTagsDetails(strUrl);

        }

        catch (Exception ex)

        {

            Response.Write(ex.Message.ToString());

        }    

    }

    private void GetMetaTagsDetails(string strUrl)

    {

        //Get Meta Tags

        var webGet = new HtmlWeb();

        var document = webGet.Load(strUrl);

        var metaTags = document.DocumentNode.SelectNodes("//meta");

        if (metaTags != null)

        {

            foreach (var tag in metaTags)

            {

                if (tag.Attributes["name"] != null && tag.Attributes["content"] != null && tag.Attributes["name"].Value == "description")

                {

                    txtDesc.Text = tag.Attributes["content"].Value;

                }

                if (tag.Attributes["name"] != null && tag.Attributes["content"] != null && tag.Attributes["name"].Value == "keywords")

                {

                    txtKeywords.Text = tag.Attributes["content"].Value;

                }

            }

        }

    }   

VB.Net Code to get Meta Description of URL

Import the following name spaces:

Imports System.Net

Imports System.Text.RegularExpressions

Imports HtmlAgilityPack

and write the code on click event of Fetch MetaTags button as:

Protected Sub btnFetchMetaTags_Click(sender As Object, e As EventArgs)

        Dim strUrl As [String] = txtUrl.Text

        Try

            'To Get Title

            Dim x As New WebClient()

            Dim pageSource As String = x.DownloadString(strUrl)

            txtTitle.Text = Regex.Match(pageSource, "\<title\b[^>]*\>\s*(?<Title>[\s\S]*?)\</title\>", RegexOptions.IgnoreCase).Groups("Title").Value

            'Creating a method to get Meta Tags like description and keyword meta tags

            GetMetaTagsDetails(strUrl)

        Catch ex As Exception

            Response.Write(ex.Message.ToString())

        End Try

    End Sub

    Private Sub GetMetaTagsDetails(strUrl As String)

        'Get Meta Tags

        Dim webGet = New HtmlWeb()

        Dim document = webGet.Load(strUrl)

        Dim metaTags = document.DocumentNode.SelectNodes("//meta")

        If metaTags IsNot Nothing Then

            For Each tag In metaTags

                If tag.Attributes("name") IsNot Nothing AndAlso tag.Attributes("content") IsNot Nothing AndAlso tag.Attributes("name").Value = "description" Then

                    txtDesc.Text = tag.Attributes("content").Value

                End If

                If tag.Attributes("name") IsNot Nothing AndAlso tag.Attributes("content") IsNot Nothing AndAlso tag.Attributes("name").Value = "keywords" Then

                    txtKeywords.Text = tag.Attributes("content").Value

                End If

            Next

        End If

    End Sub

Step 6: Build the solutions and run the website. You will get Title, Description and Keywords Meta tags of the entered URL.

Now over to you:

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