GridView PageSize Change based on TextBox and show no of record in Label using C# and VB.Net in ASP.Net

Hi Waghmare,

Refer the below sample.

HTML

<asp:Content ID="Content1" ContentPlaceHolderID="head" runat="Server">
    <style type="text/css">
        body
        {
            font-family: Arial;
            font-size: 10pt;
        }
        table
        {
            border: 1px solid #ccc;
        }
        table th
        {
            background-color: #F7F7F7;
            color: #333;
            font-weight: bold;
        }
        table th, table td
        {
            padding: 5px;
            border-color: #ccc;
        }
    </style>
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" runat="Server">
    <asp:ScriptManager runat="server" />
    <asp:UpdatePanel runat="server">
        <ContentTemplate>
            <br />
            <br />
            <div>
                <asp:HiddenField ID="hfClassApplied" runat="server" />
                <asp:GridView ID="gvCustomers" runat="server" AutoGenerateColumns="false" AllowPaging="true"
                    PageSize="5" OnPageIndexChanging="gvCustomers_PageIndexChanging" OnRowDataBound="RowDataBound">
                    <Columns>
                        <asp:TemplateField>
                            <HeaderTemplate>
                                <asp:Label ID="lblCustomerID" Text="CustomerID" runat="server" />
                                <asp:TextBox ID="txtCustomerID" runat="server" AutoPostBack="true" OnTextChanged="TextChanged" />
                                <asp:LinkButton ID="lnkCustomerID" runat="server" OnClick="Sort" CssClass="glyphicon glyphicon-arrow-up"></asp:LinkButton>
                            </HeaderTemplate>
                            <ItemTemplate>
                                <asp:Label ID="Label2" Text='<%# Eval("CustomerID") %>' runat="server" />
                            </ItemTemplate>
                        </asp:TemplateField>
                        <asp:TemplateField>
                            <HeaderTemplate>
                                <asp:Label ID="lblCompanyName" Text="CompanyName" runat="server" />
                                <asp:TextBox ID="txtCompanyName" runat="server" AutoPostBack="true" OnTextChanged="TextChanged" />
                                <asp:LinkButton ID="lnkCompanyName" runat="server" OnClick="Sort" CssClass="glyphicon glyphicon-arrow-up"></asp:LinkButton>
                            </HeaderTemplate>
                            <ItemTemplate>
                                <asp:Label ID="Label1" Text='<%# Eval("CompanyName") %>' runat="server" />
                            </ItemTemplate>
                        </asp:TemplateField>
                        <asp:TemplateField>
                            <HeaderTemplate>
                                <asp:Label ID="lblContactName" Text="ContactName" runat="server" />
                                <asp:TextBox ID="txtContactName" runat="server" AutoPostBack="true" OnTextChanged="TextChanged" />
                                <asp:LinkButton ID="lnkContactName" runat="server" OnClick="Sort" CssClass="glyphicon glyphicon-arrow-up"></asp:LinkButton>
                            </HeaderTemplate>
                            <ItemTemplate>
                                <asp:Label ID="Label2" Text='<%# Eval("ContactName") %>' runat="server" />
                            </ItemTemplate>
                        </asp:TemplateField>
                        <asp:TemplateField>
                            <HeaderTemplate>
                                <asp:Label ID="lblCity" Text="City" runat="server" />
                                <asp:TextBox ID="txtCity" runat="server" AutoPostBack="true" OnTextChanged="TextChanged" />
                                <asp:LinkButton ID="lnkCity" runat="server" OnClick="Sort" CssClass="glyphicon glyphicon-arrow-up"></asp:LinkButton>
                            </HeaderTemplate>
                            <ItemTemplate>
                                <asp:Label ID="Label3" Text='<%# Eval("City") %>' runat="server" />
                            </ItemTemplate>
                        </asp:TemplateField>
                        <asp:TemplateField>
                            <HeaderTemplate>
                                <asp:Label ID="lblCountry" Text="Country" runat="server" />
                                <asp:TextBox ID="txtCountry" runat="server" AutoPostBack="true" OnTextChanged="TextChanged" />
                                <asp:LinkButton ID="lnkCountry" runat="server" OnClick="Sort" CssClass="glyphicon glyphicon-arrow-up"></asp:LinkButton>
                            </HeaderTemplate>
                            <ItemTemplate>
                                <asp:Label ID="Label4" Text='<%# Eval("Country") %>' runat="server" />
                            </ItemTemplate>
                        </asp:TemplateField>
                    </Columns>
                </asp:GridView>
                <br />
                <asp:TextBox runat="server" ID="txtPageSize" AutoPostBack="true" OnTextChanged="Change" />
                <asp:Label ID="lblRecordDetails" runat="server" />
            </div>
        </ContentTemplate>
    </asp:UpdatePanel>
</asp:Content>

C#

public string sortDirection
{
    get
    {
        return ViewState["sortDirection"] == null ? "ASC" : ViewState["sortDirection"].ToString(); // your default sort direction i.e. ASC.
    }
    set
    {
        ViewState["sortDirection"] = value;
    }
}
public string sortExpression
{
    get
    {
        return ViewState["SortExpression"] == null ? "CustomerID" : ViewState["SortExpression"].ToString(); //Your by default sort expression. i.e. ColumnName
    }
    set
    {
        ViewState["SortExpression"] = value;
    }
}
static int totalRecord = 0;
string constr = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
protected void Page_Load(object sender, EventArgs e)
{
    if (!IsPostBack)
    {
        BindGrid();
        lblRecordDetails.Text = gvCustomers.Rows.Count.ToString() + " records out of " + totalRecord;
    }
}
protected void RowDataBound(object sender, GridViewRowEventArgs e)
{
    if (e.Row.RowType == DataControlRowType.Header)
    {
        LinkButton lnkCustomerID = e.Row.FindControl("lnkCustomerID") as LinkButton;
        LinkButton lnkCompanyName = e.Row.FindControl("lnkCompanyName") as LinkButton;
        LinkButton lnkContactName = e.Row.FindControl("lnkContactName") as LinkButton;
        LinkButton lnkCity = e.Row.FindControl("lnkCity") as LinkButton;
        LinkButton lnkCountry = e.Row.FindControl("lnkCountry") as LinkButton;
        Label lblCustomerID = e.Row.FindControl("lblCustomerID") as Label;
        Label lblCompanyName = e.Row.FindControl("lblCompanyName") as Label;
        Label lblContactName = e.Row.FindControl("lblContactName") as Label;
        Label lblCity = e.Row.FindControl("lblCity") as Label;
        Label lblCountry = e.Row.FindControl("lblCountry") as Label;

        if (!string.IsNullOrEmpty(hfClassApplied.Value))
        {
            if (sortExpression == lblCustomerID.Text)
            {
                lnkCustomerID.CssClass = hfClassApplied.Value;
            }
            if (sortExpression == lblCompanyName.Text)
            {
                lnkCompanyName.CssClass = hfClassApplied.Value;
            }
            if (sortExpression == lblContactName.Text)
            {
                lnkContactName.CssClass = hfClassApplied.Value;
            }
            if (sortExpression == lblCity.Text)
            {
                lnkCity.CssClass = hfClassApplied.Value;
            }
            if (sortExpression == lblCountry.Text)
            {
                lnkCountry.CssClass = hfClassApplied.Value;
            }
        }
    }
}
public void BindGrid()
{
    using (SqlConnection con = new SqlConnection(constr))
    {
        using (SqlCommand cmd = new SqlCommand())
        {
            cmd.CommandText = "SELECT TOP 29 [CustomerID],[CompanyName],[ContactName],[City],[Country] FROM [Customers]";
            cmd.Connection = con;
            SqlDataAdapter sda = new SqlDataAdapter(cmd);
            DataTable dt = new DataTable();
            sda.Fill(dt);
            if (dt.Rows.Count > 0)
            {
                totalRecord = dt.Rows.Count;
            }
            if (ViewState["GridView"] == null)
            {
                ViewState["GridView"] = dt;
            }
            gvCustomers.DataSource = ViewState["GridView"] as DataTable;
            gvCustomers.DataBind();
        }
    }
}
protected void gvCustomers_PageIndexChanging(object sender, GridViewPageEventArgs e)
{
    gvCustomers.PageIndex = e.NewPageIndex;
    SortGridView(sortExpression);
    lblRecordDetails.Text = gvCustomers.Rows.Count.ToString() + " records out of " + totalRecord;
}
protected void Sort(object sender, EventArgs e)
{
    string assignedClass = (sender as LinkButton).CssClass.Split('-')[2];
    if (assignedClass.ToUpper() == "UP")
    {
        sortDirection = "ASC";
        hfClassApplied.Value = "glyphicon glyphicon-arrow-down";
    }
    else
    {
        sortDirection = "DESC";
        hfClassApplied.Value = "glyphicon glyphicon-arrow-up";
    }
    string selectedId = (sender as LinkButton).ID;
    Label lblCustomerID = (sender as LinkButton).FindControl("lblCustomerID") as Label;
    Label lblCompanyName = (sender as LinkButton).FindControl("lblCompanyName") as Label;
    Label lblContactName = (sender as LinkButton).FindControl("lblContactName") as Label;
    Label lblCity = (sender as LinkButton).FindControl("lblCity") as Label;
    Label lblCountry = (sender as LinkButton).FindControl("lblCountry") as Label;
    LinkButton lnkCustomerID = (sender as LinkButton).FindControl("lnkCustomerID") as LinkButton;
    LinkButton lnkCompanyName = (sender as LinkButton).FindControl("lnkCompanyName") as LinkButton;
    LinkButton lnkContactName = (sender as LinkButton).FindControl("lnkContactName") as LinkButton;
    LinkButton lnkCity = (sender as LinkButton).FindControl("lnkCity") as LinkButton;
    LinkButton lnkCountry = (sender as LinkButton).FindControl("lnkCountry") as LinkButton;

    if (lnkCustomerID.ID == selectedId)
    {
        sortExpression = lblCustomerID.Text;
    }
    if (lnkCompanyName.ID == selectedId)
    {
        sortExpression = lblCompanyName.Text;
    }
    if (lnkContactName.ID == selectedId)
    {
        sortExpression = lblContactName.Text;
    }
    if (lnkCity.ID == selectedId)
    {
        sortExpression = lblCity.Text;
    }
    if (lnkCountry.ID == selectedId)
    {
        sortExpression = lblCountry.Text;
    }
    SortGridView(sortExpression);
}
private void SortGridView(string sortExpression)
{
    DataTable dt = new DataTable();

    if (ViewState["GridView"] != null)
    {
        dt = ViewState["GridView"] as DataTable;
    }
    DataView dv = new DataView(dt);
    if (sortDirection == "ASC")
    {
        dv.Sort = sortExpression + " " + "ASC";
    }
    else
    {
        dv.Sort = sortExpression + " " + "DESC";
    }
    gvCustomers.DataSource = dv;
    gvCustomers.DataBind();
}
protected void TextChanged(object sender, EventArgs e)
{
    GridViewRow row = ((sender as TextBox).NamingContainer as GridViewRow);
    TextBox txtCustomerID = row.FindControl("txtCustomerID") as TextBox;
    TextBox txtCompanyName = row.FindControl("txtCompanyName") as TextBox;
    TextBox txtContactName = row.FindControl("txtContactName") as TextBox;
    TextBox txtCity = row.FindControl("txtCity") as TextBox;
    TextBox txtCountry = row.FindControl("txtCountry") as TextBox;
    string query = "SELECT [CustomerID],[CompanyName],[ContactName],[City],[Country] FROM [Customers]";
    string whereQuery = string.Empty;
    using (SqlConnection con = new SqlConnection(constr))
    {
        if (!string.IsNullOrEmpty(txtCustomerID.Text))
        {
            whereQuery += " CustomerID LIKE '" + txtCustomerID.Text.Trim() + "%'";
        }
        if (!string.IsNullOrEmpty(txtCompanyName.Text))
        {
            if (!string.IsNullOrEmpty(whereQuery))
            {
                whereQuery += " AND CompanyName LIKE '" + txtCompanyName.Text.Trim() + "%'";
            }
            else
            {
                whereQuery += " CompanyName LIKE '" + txtCompanyName.Text.Trim() + "%'";
            }
        }
        if (!string.IsNullOrEmpty(txtContactName.Text))
        {
            if (!string.IsNullOrEmpty(whereQuery))
            {
                whereQuery += " AND ContactName LIKE '" + txtContactName.Text.Trim() + "%'";
            }
            else
            {
                whereQuery += " ContactName LIKE '" + txtContactName.Text.Trim() + "%'";
            }
        }
        if (!string.IsNullOrEmpty(txtCity.Text))
        {
            if (!string.IsNullOrEmpty(whereQuery))
            {
                whereQuery += " AND City LIKE '" + txtCity.Text.Trim() + "%'";
            }
            else
            {
                whereQuery += " City LIKE '" + txtCity.Text.Trim() + "%'";
            }
        }
        if (!string.IsNullOrEmpty(txtCountry.Text))
        {
            if (!string.IsNullOrEmpty(whereQuery))
            {
                whereQuery += " AND Country LIKE '" + txtCountry.Text.Trim() + "%'";
            }
            else
            {
                whereQuery += " Country LIKE '" + txtCountry.Text.Trim() + "%'";
            }
        }

        whereQuery = !string.IsNullOrEmpty(whereQuery) ? " WHERE " + whereQuery : whereQuery;

        query += whereQuery;
        using (SqlCommand cmd = new SqlCommand(query, con))
        {
            SqlDataAdapter sda = new SqlDataAdapter(cmd);
            DataTable dt = new DataTable();
            sda.Fill(dt);
            if (dt.Rows.Count > 0)
            {
                if (ViewState["GridView"] != null)
                {
                    ViewState["GridView"] = dt;
                }
                gvCustomers.DataSource = ViewState["GridView"] as DataTable;
                gvCustomers.DataBind();
            }
            else
            {
                ScriptManager.RegisterClientScriptBlock(Page, this.GetType(), "Alert", "alert('No Records Found!!')", true);
            }
        }
    }
}
protected void Change(object sender, EventArgs e)
{
    gvCustomers.PageSize = Convert.ToInt32(txtPageSize.Text.Trim());
    BindGrid();
    gvCustomers.PageIndex = 0;
    gvCustomers.DataBind();
    lblRecordDetails.Text = gvCustomers.Rows.Count.ToString() + " records out of " + totalRecord;
}

Screenshot