DockPanel 子窗体如何在父窗体打开另一子窗体，以选项卡式存在

父窗体代码：

//dockPanel1为DockPanel的实例

FrmOption frmOption = new FrmOption(dockPanel1);

frmOption.Show(dockPanel1);

子窗体代码:

public partial class FrmOption : DockContent

{

    private readonly DockPanel dockPanel1 = new DockPanel();



    public FrmOption(DockPanel dockPanel1)

    {

        InitializeComponent();

        this.dockPanel1 = dockPanel1;

    }



    private void FrmOption_Load(object sender, EventArgs e)

    {

        //调用父窗体的ToolStripProgressBar ,在父窗体ToolStripProgressBar 
必须设置为Modifier=Internal以上级别

        ToolStripProgressBar toolStripProgressBar = ((MainForm)MdiParent).toolStripProgressBar;

        toolStripProgressBar.Visible = true;

        toolStripProgressBar.Value = 90;

    }



    private void button1_Click(object sender, EventArgs e)

    {

        MainForm mainForm = MdiParent as MainForm;

        foreach (Form child in mainForm.MdiChildren)

        {

            //此处将在父窗体选项卡上显示

            if (child.Name == "FrmDepartment")

            {

                child.Activate();

                return;

            }

        }

        FrmDepartment frm = new FrmDepartment();

        frm.Show(dockPanel1);

    }

}