一个遍历页面控件ID并放入DropDown供选择的UITypeEditor

今天做一个Web控件，其中一个属性是让用户选择页面上的一个DropDownList的ID，为了更好的用户设计体验，我想把控件所在页面的所有的DropDownList控件都遍历出来，然后用户直接选择就可以了。这需要写一个设计器用的类，派生自UITypeEditor，代码如下：

using System;
using System.Drawing.Design;
using System.Web.UI;
using System.Windows.Forms;
using System.Windows.Forms.Design;

namespace MvcApp.WebForms.Controls
{
	public class IteratePageControlsUITypeEditor : UITypeEditor
	{
		public override UITypeEditorEditStyle GetEditStyle(System.ComponentModel.ITypeDescriptorContext context)
		{
			return UITypeEditorEditStyle.DropDown;
		}

		public override object EditValue(System.ComponentModel.ITypeDescriptorContext context, IServiceProvider provider, object value)
		{
			IWindowsFormsEditorService service = provider.GetService(typeof(IWindowsFormsEditorService)) as IWindowsFormsEditorService;
			ListBox lbValues = new ListBox();
			lbValues.BorderStyle = BorderStyle.None;
			IteratePageDropDownList(lbValues, context, value);
			lbValues.Click += (sender, arg) =>
			{
				service.CloseDropDown();
			};
			service.DropDownControl(lbValues);
			if (lbValues.SelectedItem != null)
				return lbValues.SelectedItem.ToString();
			else
				return "";
		}

		private void IteratePageDropDownList(ListBox lbValues, System.ComponentModel.ITypeDescriptorContext context, object value)
		{
			System.Web.UI.WebControls.WebControl self = context.Instance as System.Web.UI.WebControls.WebControl;
			Page page=null;
			if (self.Site.Container.Components.Count > 0)
				page = self.Site.Container.Components[0] as Page;
			int currentIndex = -1;
			foreach (System.Web.UI.Control item in page.Controls)
			{
				if (item is System.Web.UI.WebControls.DropDownList == false || self.ID == item.ID)
					continue;
				currentIndex = lbValues.Items.Add(item.ID);
				if (item.ID == value.ToString())
					lbValues.SelectedIndex = currentIndex;
			}
		}
	}
}

 

使用的时候，只需要在我的控件的属性上声明一下就可以了:

[Editor(typeof(IteratePageControlsUITypeEditor), typeof(System.Drawing.Design.UITypeEditor))]
public string ClientDropDownListID
{
	get { return m_ClientDropDownListID; }
	set { m_ClientDropDownListID = value; }
}