how to access or have reference using web parts?

Question

public partial class VisualWebPart1UserControl : UserControl
{
    public string SetId{ get; set; }

    protected void ddl_SelectedIndexChanged(object sender, EventArgs e)
    {
         SetId = ddl.SelectedItem.Value;
    }

}
WebPart Implementation (VisualWebPart1.cs)

public class VisualWebPart1 : WebPart
{
    private const string _ascxPath = @"~/_CONTROLTEMPLATES/mypath/VisualWebPart1/VisualWebPart1UserControl.ascx";

    protected override void CreateChildControls()
    {
        //generated by visual studio
        //Control control = Page.LoadControl(_ascxPath);
        //Controls.Add(control);

        var control = (VisualWebPart1UserControl) Page.LoadControl(_ascxPath);

        if (!string.IsNullOrEmpty(control.SetId)) //<<<NULL 
        {

        }

    }
}

UPDATED:

Below code is what I have in my usercontrol.ascx page and my question is how can I access the dropdownlist or textbox from outside the page. which is: class1.cs

  <tr>
            <td>
                <fieldset title="Configured Tabs">
                    <legend>Configured Tabs</legend>
                    <asp:Panel ID="panelConfiguredTabs" runat="server">
                        <table cellpadding="5px" cellspacing="5px">
                            <tr style="padding-top: 5px; padding-bottom: 5px">
                                <td>
                                    <asp:Label runat="server" ID="labelConfiguredTabs" Text="Tab list:"></asp:Label>
                                </td>
                                <td colspan="2" align="right">
                                    <asp:DropDownList ID="dropDownConfiguredTabs" runat="server" EnableViewState="true"
                                        AutoPostBack="true" OnTextChanged="dropDownConfiguredTabs_OnTextChanged">
                                        <asp:ListItem Text="Select one" Value="Select one"></asp:ListItem>
                                    </asp:DropDownList>
                                </td>
                            </tr>
                            <tr style="padding-top: 5px">
                                <td align="center">
                                    <asp:Button runat="server" ID="buttonAddNewTab" Text="Add New" OnClick="ButtonAddNewTab_OnClick"
                                        CausesValidation="false" />
                                </td>
                                <td align="center">
                                    <asp:Button runat="server" ID="buttonEditTab" Text="Edit" OnClick="ButtonEditTab_OnClick"
                                        CausesValidation="false" />
                                </td>
                                <td align="center">
                                    <asp:Button runat="server" ID="buttonDeleteTab" Text="Delete" OnClick="ButtonDeleteTab_OnClick"
                                        CausesValidation="false" />
                                </td>
                            </tr>
                        </table>
                    </asp:Panel>
                </fieldset>
            </td>
        </tr>

I am working on the custom web part bit advance topic.

I have a created visual web part (creates usercontrol.ascx and .cs file)

So on the root I have a class and I am trying to access the prop/method of usercontrol.ascx, how can I do that?

Answer 1

From what i understand, you want to access a property/method from your UserControl in your WebPart? If so, just make them public!

UserControl Implementation (VisualWebPartControl1.cs):

public partial class VisualWebPart1UserControl : UserControl
{
    public string Something { get; set; }

    protected void Page_Load(object sender, EventArgs e)
    {
    }

    public void DoThisAndThat()
    {
        //run some code
    }
}

WebPart Implementation (VisualWebPart1.cs)

public class VisualWebPart1 : WebPart
{
    private const string _ascxPath = @"~/_CONTROLTEMPLATES/mypath/VisualWebPart1/VisualWebPart1UserControl.ascx";

    protected override void CreateChildControls()
    {
        //generated by visual studio
        //Control control = Page.LoadControl(_ascxPath);
        //Controls.Add(control);

        var control = (VisualWebPart1UserControl) Page.LoadControl(_ascxPath);
        control.Something = "its working!";
        control.DoThisAndThat();
    }
}

hope this helps