用委托来实现子窗体操作父窗体中的控件

namespace WindowsApplication2
{
public delegate void SetVisiableHandler();
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}

private void button1_Click(object sender, EventArgs e)
{
Form2 frm = new Form2(new SetVisiableHandler(SetVisiable));
frm.Show();
}

private void SetVisiable()
{
SetVisiable(this.label1, !this.label1.Visible);
}

private void SetVisiable(Control control, bool visiable)
{
if (this.Controls.Contains(control))
{
control.Visible = visiable;
}
}
}
}

namespace WindowsApplication2
{
public partial class Form2 : Form    {
private SetVisiableHandler m_setVisible;
public Form2(SetVisiableHandler setvisible)
{
InitializeComponent();
this.m_setVisible = setvisible;
}

private void btnVisible_Click(object sender, EventArgs e)
{
if (this.m_setVisible != null)
{
this.m_setVisible();
}
}
}
}