Display (Show) selected GridView Image outside Image control using C# and VB.Net in ASP.Net

Hi jochk12345,

Refer below sample code.

HTML

<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="false" OnRowCommand="GridView1_RowCommand">
    <Columns>
        <asp:BoundField DataField="Id" HeaderText="Id" />
        <asp:BoundField DataField="Name" HeaderText="Name" />
        <asp:TemplateField>
            <ItemTemplate>
                <asp:Image ID="Image1" runat="server" ImageUrl='<%# Eval("Url") %>' />
            </ItemTemplate>
        </asp:TemplateField>
        <asp:TemplateField>
            <ItemTemplate>
                <asp:Button Text="View" runat="server" CommandName="View" CommandArgument="<%# Container.DataItemIndex %>" />
            </ItemTemplate>
        </asp:TemplateField>
    </Columns>
</asp:GridView>
<hr />
<asp:Image ID="Image1" runat="server" />

Namespaces

C#

using System.Data;

VB.Net

Imports System.Data

Code

C#

protected void Page_Load(object sender, EventArgs e)
{
    if (!this.IsPostBack)
    {
        DataTable dt = new DataTable();
        dt.Columns.AddRange(new DataColumn[3] { new DataColumn("Id"), new DataColumn("Name"), new DataColumn("Url") });
        dt.Rows.Add(1, "Chrysanthemum", "~/Images/Chrysanthemum.jpg");
        dt.Rows.Add(2, "Desert", "~/Images/Desert.jpg");
        GridView1.DataSource = dt;
        GridView1.DataBind();
    }
}

protected void GridView1_RowCommand(object sender, GridViewCommandEventArgs e)
{
    if (e.CommandName == "View")
    {
        int rowIndex = Convert.ToInt32(e.CommandArgument);
        GridViewRow row = GridView1.Rows[rowIndex];
        Image img = (Image)row.FindControl("Image1");
        Image1.ImageUrl = img.ImageUrl;
    }
}

VB.Net

Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
    If Not Me.IsPostBack Then
        Dim dt As DataTable = New DataTable()
        dt.Columns.AddRange(New DataColumn(2) {New DataColumn("Id"), New DataColumn("Name"), New DataColumn("Url")})
        dt.Rows.Add(1, "Chrysanthemum", "~/Images/Chrysanthemum.jpg")
        dt.Rows.Add(2, "Desert", "~/Images/Desert.jpg")
        GridView1.DataSource = dt
        GridView1.DataBind()
    End If
End Sub

Protected Sub GridView1_RowCommand(ByVal sender As Object, ByVal e As GridViewCommandEventArgs)
    If e.CommandName = "View" Then
        Dim rowIndex As Integer = Convert.ToInt32(e.CommandArgument)
        Dim row As GridViewRow = GridView1.Rows(rowIndex)
        Dim img As Image = CType(row.FindControl("Image1"), Image)
        Image1.ImageUrl = img.ImageUrl
    End If
End Sub

Screenshot