Question

I found some informations on the internet but nothing helped me out.
How can I merge a toolstrip in the parent mdi form?

Edit:

It worked for me with this code:

private void MainForm_MdiChildActivate(object sender, EventArgs e)
{
    IChildWindow child = ActiveMdiChild as IChildWindow;

    if (child != null)
    {
        ToolStripManager.Merge(child.ToolStrip, toolStrip1);
        child.ToolStrip.Hide();

        child.FormClosing += delegate(object sender2, FormClosingEventArgs fe)
        {
            child.ToolStrip.Show();
            ToolStripManager.RevertMerge(toolStrip1, child.ToolStrip);
        };
    }
}

Answer 1

You need to use a ToolStripManager. It has a method called Merge(ToolStrip, ToolStrip) which does what you want to.
See here

For example:

ToolStripManager.Merge(((YourChildForm)this.ActiveMdiChild).ToolStrip, parentFormToolStrip);