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How do C programming principles influence C# .NET development, and how can understanding C help in mastering C#? Discuss the similarities in syntax, differences in memory management, the role of pointers, object-oriented programming concepts, platform independence, and use case differences. Share your experiences and insights on transitioning from C to C#.

<%@ Control Language="C#" AutoEventWireup="true" CodeBehind="First2023WebUserControl.ascx.cs" Inherits="First2023Control.UserControls.First2023WebUserControl" %>
<asp:Label ID="Label1" runat="server" Text="Hello Year 2023"></asp:Label>
<p>
     </p>
Category:<asp:DropDownList ID="ddlCategory" runat="server" AutoPostBack="True" OnSelectedIndexChanged="ddlCategory_SelectedIndexChanged">
</asp:DropDownList>
<p>
    Subcategory:
    <asp:DropDownList ID="ddlSubcategory" runat="server" AutoPostBack="True">
    </asp:DropDownList>
</p>
<p>
    <asp:Label ID="Label2" runat="server" Text="Label"></asp:Label>
</p>
<asp:Button ID="Button1" runat="server" OnClick="Button1_Click" Text="Button" />
<asp:Label ID="Label3" runat="server" Text="Label"></asp:Label>

protected void Page_Load(object sender, EventArgs e)
{

        Label3.Text = "In Page Load selected index is " + ddlCategory.SelectedIndex.ToString();
        XXXDbSupport objDBSupport = new XXXDbSupport();
        DbCommand objDBCommand = objDBSupport.CreateDbCommand();
        objDBCommand.CommandType = CommandType.Text;
        string sSQL = "select distinct isnull(Category,'(blank)') as ProdCat from xxx_product order by isnull(Category,'(blank)')";
        objDBCommand.CommandText = sSQL;
        DataTable objDBTable = objDBSupport.FillDataTable(objDBCommand);
        if (objDBTable.Rows.Count > 0)
        {
            ddlCategory.DataTextField = "ProdCat";
            ddlCategory.DataValueField = "ProdCat";
            ddlCategory.DataSource = objDBTable;
            ddlCategory.DataBind();
        }
        else
        {
            ddlCategory.Text = "n/a";
        }

}

protected void ddlCategory_SelectedIndexChanged(object sender, EventArgs e)
{
    Label2.Text = "The selected index changed to " + ddlCategory.SelectedIndex.ToString();
    XXXDbSupport objDBSupport = new XXXDbSupport();
    DbCommand objDBCommand = objDBSupport.CreateDbCommand();
    objDBCommand.CommandType = CommandType.Text;
    string sSQL = "select distinct isnull(SubCategory,'(blank)') as SubCat from xxx_product ";
    if (ddlCategory.Text == "(blank)")
    {
        sSQL = sSQL + "where isnull(Category,'(blank)') = '(blank)' order by isnull(SubCategory,'(blank)')";
    }
    else
    {
        sSQL = sSQL + "where Category = '" + ddlCategory.Text + "' order by isnull(SubCategory,'(blank)')";
    }
    objDBCommand.CommandText = sSQL;
    DataTable objDBTable = objDBSupport.FillDataTable(objDBCommand);
    if (objDBTable.Rows.Count > 0)
    {
        ddlSubcategory.DataTextField = "SubCat";
        ddlSubcategory.DataValueField = "SubCat";
        ddlSubcategory.DataSource = objDBTable;
        ddlSubcategory.DataBind();
    }
    else
    {
        ddlSubcategory.Text = "n/a";
    }

}

<%@ Control Language="C#" AutoEventWireup="true" CodeBehind="First2023WebUserControl.ascx.cs" Inherits="First2023Control.UserControls.First2023WebUserControl" %>
<asp:Label ID="Label1" runat="server" Text="Hello Year 2023"></asp:Label>
<p>
     </p>
Category:<asp:DropDownList ID="ddlCategory" runat="server" AutoPostBack="True" OnSelectedIndexChanged="ddlCategory_SelectedIndexChanged">
</asp:DropDownList>
<p>
    Subcategory:
    <asp:DropDownList ID="ddlSubcategory" runat="server" AutoPostBack="True">
    </asp:DropDownList>
</p>
<p>
    <asp:Label ID="Label2" runat="server" Text="Label"></asp:Label>
</p>
<asp:Button ID="Button1" runat="server" OnClick="Button1_Click" Text="Button" />
<asp:Label ID="Label3" runat="server" Text="Label"></asp:Label>