CODEWITHSUNDEEP
winformsbindingtoolstripdropdowntoolstripcontrolhost
Cason
Cason

Reputation: 95

ListControl.DataSource in ToolStipControlHost not function

I use a ToolStripControlHost to wrap a ListBox control for adding it into a ToolStripDropDown, but found items I assign to ListBox.DataSource not shown up, and ComboBox.DataSource not work as well, I don't understand why ListContorl.DataSource not function in ToolStripControlHost.

        ListBox listBox = new ListBox();
        listBox.DataSource = new string[] { "1", "2", "3" };

        ToolStripControlHost host = new ToolStripControlHost(listBox)
        {
            Margin = Padding.Empty,
            Padding = Padding.Empty,
            AutoSize = false
        };

        ToolStripDropDown dropDown = new ToolStripDropDown() { AutoClose = false };
        dropDown.Items.Add(host);
        dropDown.Show();

Edit

I found the problem is ToolStripDropDown has not parents to provide BindingContext, so it will happen to any control with DataManager.

Upvotes: 2

Views: 188

Answers (2)

Cason
Cason

Reputation: 95

I found the problem is ToolStripDropDown has no parents to provide a BindingContext, so the solution is assign the BindingContext of the Form. 

        ListBox listBox = new ListBox();
        listBox.DataSource = new string[] { "1", "2", "3" };
        listBox.BindingContext = this.BindingContext; //assign a BindingContext

        ToolStripControlHost host = new ToolStripControlHost(listBox)
        {
            Margin = Padding.Empty,
            Padding = Padding.Empty,
            AutoSize = false
        };

        ToolStripDropDown dropDown = new ToolStripDropDown() { AutoClose = false };
        dropDown.Items.Add(host);
        dropDown.Show();

Upvotes: 0

Loathing
Loathing

Reputation: 5266

Good question. Seems like the ListBox has to be added to a top level control (such as a Form) in order to force it to use the DataSource property. E.g. Add this code after the DataSource is assigned:

public class DataForm : Form {

    ToolStripDropDown dropDown = new ToolStripDropDown() { AutoClose = true };
    ListBox listBox = new ListBox();
    public DataForm() {
        listBox.DataSource = new string[] { "1", "2", "3" };
        var hWnd = listBox.Handle; // required to force handle creation
        using (var f = new Form()) {
            f.Controls.Add(listBox);
            f.Controls.Remove(listBox);
        }

        ToolStripControlHost host = new ToolStripControlHost(listBox) {
            Margin = Padding.Empty,
            Padding = Padding.Empty,
            AutoSize = false
        };

        dropDown.Items.Add(host);
    }

    protected override void OnMouseClick(MouseEventArgs e) {
        base.OnMouseClick(e);
        dropDown.Show(Cursor.Position);
    }
}

You could also look at the ListBox.cs source code to try and figure out underlying cause: http://referencesource.microsoft.com/#System.Windows.Forms/winforms/Managed/System/WinForms/ListBox.cs,03c7f20ed985c1fc

Upvotes: 1

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