How do I add a Menuitem to a Menustrip from a DLL

Franz Heyn

2y740C#

hi,

well half of the question I've already answered, there's no problem modifying an Application's Menustrip, you just have to send the DLL

the Apps Menustrip-object. The dropdownitems Click-Event does not work.

How I did it:

DbMenuOwner receives the MenuStrip-Object

When the DLL is loaded, I check DbMenuOwner and call AddDbMenu().

        public override void Load(string databasename)
         {
           if (DbMenuOwner != null)
               AddDbMenu();
        }

The DLL-Method AddDbMenu looks like this :

        protected void AddDbMenu()
        {
           System.Windows.Forms.ToolStripMenuItem tsmi = new System.Windows.Forms.ToolStripMenuItem();
           tsmi.Text = "Database";
           tsiSelect = tsmi.DropDownItems.Add("Select");
           tsiSelect.Click += new EventHandler(tsiDatabaseSelect_Click);

DbMenuOwner.Items.Insert(1, tsmi);
}

        public void tsiDatabaseSelect_Click(object sender, EventArgs e)
        {
           this.DatabaseUI();
       }

When I run the Application and click the "Select"-Item, the App crashes.

Any ideas what I'm doing wrong here, or is there something missing?

One important note: I do not want to add any Code to my Application.

for your answers many thanks in advance

Franz

2 Replies

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Franz Heyn2y ago
thanks for your answer

the only difference between your suggestion and mine is the MenuStrips public state.

In my DLL I do not use a public Method instead I use a public property DbMenuOwner to pass the MenuStrip-Object to the DLL

Setting the MenuStrip public however did not solve my problem, there's still a nullreference-exception
+1

Tuhin Paul2y ago

In your DLL, create a public method that will add the MenuItem to the MenuStrip. This method should take the MenuStrip as a parameter.

public class MyDll
{
    public void AddMenuItem(MenuStrip menuStrip)
    {
        // Create a new MenuItem
        ToolStripMenuItem menuItem = new ToolStripMenuItem("My MenuItem");

        // Add the MenuItem to the MenuStrip
        menuStrip.Items.Add(menuItem);
    }
}

In your main project, add a reference to the DLL. In your main project, call the AddMenuItem method and pass the MenuStrip as a parameter.

public class MainForm : Form
{
    private MenuStrip menuStrip1;

    public MainForm()
    {
        InitializeComponent();

        // Create an instance of the DLL
        MyDll myDll = new MyDll();

        // Call the AddMenuItem method
        myDll.AddMenuItem(menuStrip1);
    }
}

Make the MenuStrip accessible

public class MainForm : Form
{
    public MenuStrip menuStrip1;
}