ListControl.DataSource in ToolStipControlHost not函数

Question

我使用ToolStripControlHost包装一个ListBox控件，以便将它添加到ToolStripDropDown中，但发现分配给ListBox.DataSource的项没有显示，ComboBox.DataSource也不工作，我不明白为什么ListContorl.DataSource在ToolStripControlHost中不起作用。

        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();

编辑

我发现问题是ToolStripDropDown没有父母提供BindingContext，所以它会发生在DataManager的任何控制上。

Answer 1

我发现问题是ToolStripDropDown没有父级来提供BindingContext，所以解决方案是分配表单的BindingContext。

        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();

Answer 2

问得好。似乎必须将ListBox添加到顶级控件(如Form)中，才能强制它使用DataSource属性。例如，在分配DataSource之后添加此代码：

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);
    }
}

您还可以查看ListBox.cs源代码，试图找出根本原因：http://referencesource.microsoft.com/#System.Windows.Forms/winforms/Managed/System/WinForms/ListBox.cs,03c7f20ed985c1fc。