Hi rani,

Check this example. Now please take its reference and correct your code.

Database

I have made use of the following table tblFilesPath with the schema as follows.

I have already inserted few records in the table.

HTML

<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap.min.css" />
<link rel="stylesheet" href="https://cdn.datatables.net/1.10.12/css/dataTables.bootstrap.min.css" />
<script type="text/javascript" src="https://code.jquery.com/jquery-3.1.1.min.js"></script>
<script type="text/javascript" src="https://cdn.datatables.net/1.10.12/js/jquery.dataTables.min.js"></script>
<script type="text/javascript" src="https://cdn.datatables.net/1.10.12/js/dataTables.bootstrap.min.js"></script>
<script type="text/javascript" src="https://code.angularjs.org/1.3.0/angular.js"></script>
<script type="text/javascript" src="https://rawgithub.com/vivendi/angular-datatables/master/src/angular-datatables.js"></script>
<script type="text/javascript" src="https://rawgithub.com/vivendi/angular-datatables/master/src/angular-datatables.directive.js"></script>
<script type="text/javascript" src="https://rawgithub.com/vivendi/angular-datatables/master/src/angular-datatables.factory.js"></script>
<script type="text/javascript" src="https://rawgithub.com/vivendi/angular-datatables/master/src/angular-datatables.bootstrap.js"></script>
<script type="text/javascript">
    var app = angular.module('MyApp', ['datatables'])
    app.controller('MyController', function ($scope, $http) {
        PopulateFiles();
        function PopulateFiles() {
            $http.post("CS.aspx/GetFiles", { headers: { 'Content-Type': 'application/json'} })
            .then(function (response) {
                $scope.Files = JSON.parse(response.data.d);
            });
        }
        $scope.Delete = function (id) {
            if (confirm("Do you want to delete this record?")) {
                $http.post("CS.aspx/DeleteFile", { id: id }, { headers: { 'Content-Type': 'application/json'} })
                .then(function (response) {
                    if (response.data.d == 0) {
                        PopulateFiles();
                    }
                });
            }
        }
    });
</script>
<div ng-app="MyApp" ng-controller="MyController">
    <div class="table table-bordered">
        <table datatable="ng" class="table table-bordered">
            <thead>
                <tr>
                    <th>Id</th>
                    <th>Name</th>
                    <th>Image</th>
                    <th>Action</th>
                </tr>
            </thead>
            <tbody>
                <tr dt-rows ng-repeat="file in Files">
                    <td>{{file.Id}}</td>
                    <td>{{file.Name}}</td>
                    <td><img ng-src="{{file.Path}}" alt="{{file.Name}}.jpg" style="height: 100px; width: 100px" /></td>
                    <td><input type="button" id="btnEdit" class="btn btn-primary" value="Edit" />
                        <input type="button" class="btn btn-danger" value="Delete" ng-click="Delete(file.Id)" /></td>                          
                </tr>
            </tbody>
        </table>
    </div>
</div>

Namespaces

C#

using System.Collections.Generic;
using System.Configuration;
using System.Data.SqlClient;
using System.Web.Script.Serialization;
using System.Web.Services;

VB.Net

Imports System.Configuration
Imports System.Data.SqlClient
Imports System.Web.Script.Serialization
Imports System.Web.Services

Code

C#

[WebMethod]
public static string GetFiles()
{
    List<object> files = new List<object>();
    string sql = "SELECT Id,Name,Path FROM tblFilesPath";
    using (SqlConnection conn = new SqlConnection())
    {
        conn.ConnectionString = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
        using (SqlCommand cmd = new SqlCommand(sql))
        {
            cmd.Connection = conn;
            conn.Open();
            using (SqlDataReader sdr = cmd.ExecuteReader())
            {
                while (sdr.Read())
                {
                    files.Add(new
                    {
                        Id = sdr["Id"],
                        Name = sdr["Name"],
                        Path = sdr["Path"]
                    });
                }
            }
            conn.Close();
        }
        return (new JavaScriptSerializer().Serialize(files));
    }
}

[WebMethod]
public static int DeleteFile(int id)
{
    string cs = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
    using (SqlConnection con = new SqlConnection(cs))
    {
        SqlCommand cmd = new SqlCommand("DELETE FROM tblFilesPath WHERE id = @Id", con);
        cmd.Parameters.AddWithValue("@Id", id);
        con.Open();
        int i = Convert.ToInt32(cmd.ExecuteScalar());
        con.Close();
        return i;
    }
}

VB.Net

<WebMethod()>
Public Shared Function GetFiles() As String
    Dim files As List(Of Object) = New List(Of Object)()
    Dim sql As String = "SELECT Id,Name,Path FROM tblFilesPath"
    Using conn As SqlConnection = New SqlConnection()
        conn.ConnectionString = ConfigurationManager.ConnectionStrings("constr").ConnectionString
        Using cmd As SqlCommand = New SqlCommand(sql)
            cmd.Connection = conn
            conn.Open()
            Using sdr As SqlDataReader = cmd.ExecuteReader()
                While sdr.Read()
                    files.Add(New With {
                        .Id = sdr("Id"),
                        .Name = sdr("Name"),
                        .Path = sdr("Path")
                    })
                End While
            End Using
            conn.Close()
        End Using
 
        Return (New JavaScriptSerializer().Serialize(files))
    End Using
End Function

<WebMethod()>
Public Shared Function DeleteFile(ByVal id As Integer) As Integer
    Dim cs As String = ConfigurationManager.ConnectionStrings("constr").ConnectionString
    Using con As SqlConnection = New SqlConnection(cs)
        Dim cmd As SqlCommand = New SqlCommand("DELETE FROM tblFilesPath WHERE id = @Id", con)
        cmd.Parameters.AddWithValue("@Id", id)
        con.Open()
        Dim i As Integer = Convert.ToInt32(cmd.ExecuteScalar())
        con.Close()
        Return i
    End Using
End Function

Screenshot