C#

FormMain:
public FormMain()
{
Form2 f2 = new Form2();    //this is the code to load form2 into panel on formMain
f2.TopLevel = false;
f2.visible = true;
this.panel1.controls.add(f2);   //asume that you have add a panel into your form

f2.callbackFn += new hidetoolstrip(this.abc)   //add the event handler when button on form2 was click
}

private void abc(boolean b)
{
  //disable or enable your toolstripmenu
}

Form2:
public hidetoolstrip callbackFn;   //create object
private void button1_Click(object sender, EventArgs e)
{
   callbackFn(True);
}

Class Delegate:
public delegate void hidetoolstrip(boolean b);

Icon icon = new Icon(typeof(this), "IconName.ico");

John Simmons / outlaw programmer wrote:

I also tried typeof(this) in the icon's constructor call, and received the compiler error Type expected for "this".

John Simmons / outlaw programmer wrote:

so I changed them to "Embedded", but that had no effect at all.

string iconName = "MyIcon";
string resolvedName = string.Format("MyAppNamespace.Resources.{0}.ico", iconName);
Stream iconStream = System.Reflection.Assembly.GetExecutingAssembly().GetManifestResourceStream(resolvedName);
m_trayIcon.Icon = new Icon(iconStream);
iconStream.Close();

string iconName = "MyIcon";
string resolvedName = string.Format("MyAppNamespace.Resources.{0}.ico", iconName);
using (Stream iconStream = System.Reflection.Assembly.GetExecutingAssembly().GetManifestResourceStream(resolvedName))
{
   m_trayIcon.Icon = new Icon(iconStream);
}

This constructor combines the namespace of the given type with the string name of the resource and looks for a match in the assembly manifest. For example you can pass in the Control type and Error.ico to this constructor and it will look for a resource named System.Windows.Forms.Error.ico.