Switching to dynamically created TabPage on button click

Question

I'm practicing my coding and am trying to create a till by Dynamically prefill the items that are stored in a text file. I can dynamically create Tabs, Buttons and create menu buttons based on the categories of items. Where I'm struggling is I'm trying to switch the Tab on a button click. The Tabs are given a Name, which is the category ID, and the Text displays the category. In the event that trys to switch the tab I get the following error:

Error CS0266 Cannot implicitly convert type 'object' to 'System.Windows.Forms.TabPage'. An explicit conversion exists (are you missing a cast?)

I'm presuming that I need to Create a tab page or something, but I can't find out how to do this. Been on it for hours! Here's my code....

public partial class Form1 : Form
{
    private void Form1_Load(object sender, EventArgs e)
    {
        string[] loadedFile = File.ReadAllLines(@"h:\shopItemsV2.txt");
        foreach (string line in loadedFile)
        {
            // Split string and create required variables
            string[] newBtnData = line.Split(',');
            int catID = int.Parse(newBtnData[0]);
            string cat = newBtnData[1];
            string item = newBtnData[2];
            double price = double.Parse(newBtnData[3]);

            // Create tab if needed
            if (tabControl1.TabCount < catID)
            {
                TabPage tp = new TabPage()
                {
                    Text = cat,
                    Name = catID.ToString()
                };
                tabControl1.TabPages.Add(tp);
                // Add FlowLayoutPanel with unique name
                FlowLayoutPanel fp = new FlowLayoutPanel()
                {
                    Name = "fp" + catID.ToString(),
                    Dock = DockStyle.Fill
                };

                // Add FlowLayoutPanel to correct Tab
                tabControl1.TabPages[catID-1].Controls.Add(fp);

                // Create Button for menu
                Button newMenuBtn = new Button()
                {
                    Name = cat + "Btn",
                    Tag = catID,
                    Width = 100,
                    Height = 50,
                    Text = cat,
                };
                newMenuBtn.Click += SwitchTab;
                menuFP.Controls.Add(newMenuBtn);
            }

            // Create Button
            Button newBtn = new Button()
            {
                Name = item,
                Tag = price,
                Width = 100,
                Height = 100,
                Text = item,
            };
            newBtn.Click += AddItem;

            //Add button to correct tab
            foreach (TabPage tabP in tabControl1.TabPages)
            {

                if (tabP.Name == catID.ToString())
                {
                    Control fp = this.Controls.Find("fp"+catID, true).First();
                    fp.Controls.Add(newBtn);
                }
            }
        }
    }

    private void SwitchTab(object sender, EventArgs e)
    {
        // Create button, switch to required Tab
        // Tabs named the same as Tag on the button
        Button clickedBtn = sender as Button;        
        tabControl1.SelectedTab = clickedBtn.Tag;
    }
}

Any help would be greatly appreciated.

Answer 1

private void AddNewPr_Click(object sender, EventArgs e)
    {
        TabPage tab = new TabPage();
        _list = new ListBox();
        _list2 = new ListBox();
        PictureBox picBox = new PictureBox();
        picBox.Click = picBox_Click;

        //More stuff here

        //Add the controls        
        tabControl1.Controls.Add(tab);
        tab.Controls.Add(list);
        tab.Controls.Add(list2);
        tab.Controls.Add(pictureBox);
    }

Answer 2

You can store anything in the Tag() property of your button. With that in mind, store a reference to your TabPage!

Change:

// Create Button for menu
Button newMenuBtn = new Button()
{
    Name = cat + "Btn",
    Tag = catID,
    Width = 100,
    Height = 50,
    Text = cat,
};

To:

// Create Button for menu
Button newMenuBtn = new Button()
{
    Name = cat + "Btn",
    Tag = tp; // store the reference to the TabPage you created
    Width = 100,
    Height = 50,
    Text = cat,
};

Then the suggestion by Uwe Keim should work:

tabControl1.SelectedTab = clickedBtn.Tag as TabPage;