Dynamically adding ToolStripMenuItems to a MenuStrip (C#/ Winforms)

问题

I have my solution implemented (basic solution) and I'm happy.

Problem is when I add new items to a ToolStripItemCollection using the 'Add' method, I get a few overloads ... the meaningful one being a string parameter, an image parameter and an EventHandler parameter.

Because my drop down list is going to be serving as a dynamic history at RunTime, means it going to be empty at compile time. This means I can't add an event handler through the standard route of using the designer surface (On click). I am forced to use the overload described above.

I image is of no use to me but adding the event handler dynamically is what I am interested in and need help with.

URL: http://msdn.microsoft.com/en-us/library/bxdt0s8t.aspx

There is no other overload to help me, so I have to use an Image ... anyone got any ideas to get around this and show me how to fully satisfy this overloaded version of the add method.

TIA.

UPDATE: I re did this again in a current project but using more slicker code but the principle is the same, add event handlers dynamically at run time. I will update this with some sample code when I get home.

回答1:

The way I do it is to create an array of ToolStripMenuItems and populate that array with the items I'm adding. I create one method to handle the click events and have it check something unique about each item I create at run-time. You might try using the Name or Tag properties of each ToolStripMenuItem. Then use AddRange on the spot in the menu you're adding to. So your code might look something like this:

private void BuildMenuItems()
{
    ToolStripMenuItem[] items = new ToolStripMenuItem[2]; // You would obviously calculate this value at runtime
    for (int i = 0; i < items.Length; i++)
    {
        items[i] = new ToolStripMenuItem();
        items[i].Name = "dynamicItem" + i.ToString();
        items[i].Tag = "specialDataHere";
        items[i].Text = "Visible Menu Text Here";    
        items[i].Click += new EventHandler(MenuItemClickHandler);
    }

    myMenu.DropDownItems.AddRange(items);
}

private void MenuItemClickHandler(object sender, EventArgs e)
{
    ToolStripMenuItem clickedItem = (ToolStripMenuItem)sender;
    // Take some action based on the data in clickedItem
}

回答2:

What is wrong with:

ToolStripItem item = toolStripItems.Add("MyItem");
item.Click += new EventHandler(....);

Am I missing something?

回答3:

I was having similar issues as Philip Wallace. It's important to note the difference between a ToolStripItem, and a ToolStripMenuItem. I was adding ToolStripItems to a ToolStripMenuItem's DropDownItems, and they would show up, and have all properties set correctly, and accessible in code, but they would not show any text! Switching to a ToolStripMenuItem solved this.

In regards to the original question, I've been using the empty constructor, and setting the fields I needed. (I'm in vb.net with .net 4.0, and it won't let me call New ToolStripMenuItem() since it has a MustInherit tag, so I made this class:

Public Class DynamicToolStripMenuItem
    Inherits ToolStripMenuItem

    Public Sub New(value As Integer, text As String, handler As System.EventHandler)
        MyBase.New()
        Me.Text = text
        Me.Visible = True
        Me.Tag = value
        AddHandler Me.Click, handler
    End Sub
End Class

回答4:

You can simply pass null for the image.

Menu.DropDownItems.Add(Text, null, EventHandler);

来源：https://stackoverflow.com/questions/1757574/dynamically-adding-toolstripmenuitems-to-a-menustrip-c-winforms

标签

winforms

menuitem