Send (Pass) checked items from DataList from to another in ASP.Net

Please refer this code.

I have used OnItemDataBound event for both DataList to convert the Byte Array in base64String format. On CheckChecked event i am selecting the Item Image URL which is in base64Format and converting it to Byte[] Array.

HTML

<form id="form1" runat="server">
<div>
    <asp:DataList ID="DataList1" runat="server" OnItemDataBound="OnItemDataBound">
        <HeaderTemplate>
            <table border="0" cellpadding="0" cellspacing="0">
                <tr>
                    <th>
                    </th>
                    <th>
                        Id
                    </th>
                    <th>
                        Name
                    </th>
                    <th>
                        Image
                    </th>
                </tr>
        </HeaderTemplate>
        <ItemTemplate>
            <tr>
                <td>
                    <asp:CheckBox ID="CheckBox1" AutoPostBack="true" OnCheckedChanged="OnCheckedChanged"
                        runat="server" />
                </td>
                <td>
                    <asp:Label ID="lblId" Text='<%# Eval("Id") %>' runat="server" />
                </td>
                <td>
                    <asp:Label ID="lblName" Text='<%# Eval("Name") %>' runat="server" />
                </td>
                <td>
                    <asp:Image ID="imgImage" runat="server" />
                </td>
            </tr>
        </ItemTemplate>
        <FooterTemplate>
            </table>
        </FooterTemplate>
    </asp:DataList>
    <br />
    <hr />
    <asp:DataList ID="DataList2" runat="server" OnItemDataBound="OnItemDataBound">
        <HeaderTemplate>
            <table border="0" cellpadding="0" cellspacing="0">
                <tr>
                    <th>
                        Id
                    </th>
                    <th>
                        Name
                    </th>
                    <th>
                        Image
                    </th>
                </tr>
        </HeaderTemplate>
        <ItemTemplate>
            <tr>
                <td>
                    <asp:Label ID="lblId" Text='<%# Eval("Id") %>' runat="server" />
                </td>
                <td>
                    <asp:Label ID="lblName" Text='<%# Eval("Name") %>' runat="server" />
                </td>
                <td>
                    <asp:Image ID="imgImage" runat="server" />
                </td>
            </tr>
        </ItemTemplate>
        <FooterTemplate>
            </table>
        </FooterTemplate>
    </asp:DataList>
</div>
</form>

Namespaces

using System.Configuration;
using System.Data.SqlClient;
using System.Data;

C#

protected void Page_Load(object sender, EventArgs e)
{
    if (!this.IsPostBack)
    {
        this.Populate();
    }
}
    
protected void OnCheckedChanged(object sender, EventArgs e)
{
    CheckBox chk = sender as CheckBox;
    DataTable dt = new DataTable();
    if (chk.Checked)
    {
        DataListItem item = chk.NamingContainer as DataListItem;
        if (ViewState["Data"] == null)
        {

            dt.Columns.AddRange(new DataColumn[3] { new DataColumn("Id", typeof(int)),
                    new DataColumn("Name", typeof(string)),
                    new DataColumn("Data",typeof(byte[])) });
            string id = (item.FindControl("lblId") as Label).Text;
            string name = (item.FindControl("lblName") as Label).Text;
            string base64String = (item.FindControl("imgImage") as Image).ImageUrl;
            byte[] bytes = Convert.FromBase64String(base64String.Split(',')[1]);
            dt.Rows.Add(id, name, bytes);
        }
        else
        {
            dt = (DataTable)ViewState["Data"];
            string id = (item.FindControl("lblId") as Label).Text;
            string name = (item.FindControl("lblName") as Label).Text;                
            string base64String = (item.FindControl("imgImage") as Image).ImageUrl;
            byte[] bytes = Convert.FromBase64String(base64String.Split(',')[1]);
            dt.Rows.Add(id, name, bytes);
        }
        this.DataList2.DataSource = dt;
        this.DataList2.DataBind();
        ViewState["Data"] = dt;
    }
}

protected void OnItemDataBound(object sender, DataListItemEventArgs e)
{
    if (e.Item.ItemType == ListItemType.Item || e.Item.ItemType == ListItemType.AlternatingItem)
    {
        byte[] bytes = (byte[])DataBinder.Eval(e.Item.DataItem, "Data");
        string base64String = Convert.ToBase64String(bytes, 0, bytes.Length);
        (e.Item.FindControl("imgImage") as Image).ImageUrl = "data:image/png;base64," + base64String;
    }
}

private void Populate()
{
    string constr = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
    using (SqlConnection con = new SqlConnection(constr))
    {
        using (SqlCommand cmd = new SqlCommand("SELECT TOP 2 * FROM tblFiles", con))
        {
            using (SqlDataAdapter da = new SqlDataAdapter(cmd))
            {
                DataTable dt = new DataTable();
                da.Fill(dt);
                DataList1.DataSource = dt;
                DataList1.DataBind();
            }
        }
    }
}

Database

CREATE TABLE [dbo].[tblFiles](
	[Id] [int] IDENTITY(1,1) NOT NULL,
	[Name] [varchar](50) NULL,
	[ContentType] [varchar](100) NULL,
	[Data] [varbinary](max) NULL
) ON [PRIMARY]

GO

Screenshot

I think you are not referring the code properly.

1. I have set OnItemDataBound event for both the DataList.
2. Your image mime type is not correct in base64String

(e.Item.FindControl("imgImage") as Image).ImageUrl = "data:image/png/jpg;base64," + base64String;

I have corrected it to

(e.Item.FindControl("imgImage") as Image).ImageUrl = "data:image/png;base64," + base64String;

3.

For price you have set Byte[]

new DataColumn("Price",typeof(byte[])) });

I have replaced it to

new DataColumn("Price",typeof(int)) });

Please check all the code once again.