FlowLayoutPanel inside a tabControl

Question

I have a tabControl and a flowLayoutPanel inside each tab.. When I drag and drop a file onto a tab it creates a button with the icon of the file dropped. But i have the option to create more tabs and I want to be able to drag files into the selected tab.. but the problem is the flowLayoutPanel when adding the button..

My code so far:

   public Process myProcess = new Process();
   FlowLayoutPanel fl_panel = new FlowLayoutPanel();

    string path_app;

    public Form1()
    {

        InitializeComponent();
     //add the flowLayoutPanel on the first tab
        fl_panel.Dock = DockStyle.Fill;
        fl_panel.BringToFront();
        tabPage1.Controls.Add(fl_panel);

        this.DragEnter += new DragEventHandler(Form1_DragEnter);
        this.DragDrop += new DragEventHandler(Form1_DragDrop);

    }

    void Form1_DragEnter(object sender, DragEventArgs e)
    {
        if (e.Data.GetDataPresent(DataFormats.FileDrop, false))
         e.Effect = DragDropEffects.All;
    }


    void Form1_DragDrop(object sender, DragEventArgs e)
    {
        string[] fileList = e.Data.GetData(DataFormats.FileDrop) as string[];

        foreach (string s in fileList)
            {

                Button button = new Button(); 
                button.Click += new EventHandler(this.button_Click);
                fl_panel.Controls.Add(button);
                path_app = String.Format("{0}", s);
                button.Tag = path_app;
                string filename = path_app;
                Icon icon = System.Drawing.Icon.ExtractAssociatedIcon(filename);
                Bitmap bmp = icon.ToBitmap();
                button.BackgroundImage = bmp;
                button.Width = 60;
                button.Height = 75;
                button.FlatStyle = FlatStyle.Flat;
                button.BackgroundImageLayout = ImageLayout.Stretch;

            }
    }
   private void button_Click(object sender, System.EventArgs e)
    {
        String path_app = ((sender as Button).Tag as String); 
        myProcess.StartInfo.FileName = path_app;
        myProcess.Start();

    }

   private void add_tab_btn_Click(object sender, EventArgs e)
    {

       //Create new tab with FLP inside
        string title = Convert.ToString(textBox1.Text);
        TabPage new_TabPage = new TabPage(title);
        fl_panel.Dock = DockStyle.Fill; 
        fl_panel.BringToFront();
        new_TabPage.Controls.Add(fl_panel);
        tabControl1.TabPages.Add(new_TabPage);
    }
}

If I use fl_panel.Controls.Add(button); it adds the buttons fine, on the first tab, but if I create a new tab I don't know how to use tabControl.SelectedTab with the fl_panel.Controls.Add(button) to add the buttons correctly on the selected tab.

Answer 1

You have to create a new FlowLayoutPanel for every tab:

FlowLayoutPanel fl_panel = new FlowLayoutPanel();
...
new_TabPage.Controls.Add(fl_panel);

And then you can cast the first element of the TabPage to the FlowLayoutPanel and access the Controls from there:

FlowLayoutPanel selectedFLP = (FlowLayoutPanel)tabControl.SelectedTab.Controls[0];
...