用户控件在设计时作为容器

Question

我正在设计一个简单的扩展器控件.

我派生自UserControl,绘制内部控件,构建,运行; 一切都好.

由于内部控件是Panel,我想在设计时将其用作容器.的确,我使用了以下属性:

[Designer(typeof(ExpanderControlDesigner))]
[Designer("System.Windows.Forms.Design.ParentControlDesigner, System.Design", typeof(IDesigner))] 

太棒了,我说.但它不是......

结果是我可以在设计时将它用作容器,但是:

• 添加的控件返回已嵌入用户控件中的内部控件
• 即使我在设计时将顶部控件添加到顶部,在运行时也会再次返回嵌入到用户控件中的控件
• 我无法在设计时将容器区域限制为Panel区域

我错过了什么？这是完整性的代码...为什么这段代码不起作用？

[Designer(typeof(ExpanderControlDesigner))]
[Designer("System.Windows.Forms.Design.ParentControlDesigner, System.Design", typeof(IDesigner))] 
public partial class ExpanderControl : UserControl
{
    public ExpanderControl()
    {
        InitializeComponent();
....

[System.Security.Permissions.PermissionSet(System.Security.Permissions.SecurityAction.Demand, Name = "FullTrust")] 
internal class ExpanderControlDesigner : ControlDesigner
{
    private ExpanderControl MyControl;

    public override void Initialize(IComponent component)
    {
        base.Initialize(component);

        MyControl = (ExpanderControl)component;

        // Hook up events
        ISelectionService s = (ISelectionService)GetService(typeof(ISelectionService));
        IComponentChangeService c = (IComponentChangeService)GetService(typeof(IComponentChangeService));

        s.SelectionChanged += new EventHandler(OnSelectionChanged);
        c.ComponentRemoving += new ComponentEventHandler(OnComponentRemoving);
    }

    private void OnSelectionChanged(object sender, System.EventArgs e)
    {

    }

    private void OnComponentRemoving(object sender, ComponentEventArgs e)
    {

    }

    protected override void Dispose(bool disposing)
    {
        ISelectionService s = (ISelectionService)GetService(typeof(ISelectionService));
        IComponentChangeService c = (IComponentChangeService)GetService(typeof(IComponentChangeService));

        // Unhook events
        s.SelectionChanged -= new EventHandler(OnSelectionChanged);
        c.ComponentRemoving -= new ComponentEventHandler(OnComponentRemoving);

        base.Dispose(disposing);
    }

    public override System.ComponentModel.Design.DesignerVerbCollection Verbs
    {
        get
        {
            DesignerVerbCollection v = new DesignerVerbCollection();

            v.Add(new DesignerVerb("&asd", new EventHandler(null)));

            return v;
        }
    }
}

我找到了很多资源(互动,设计,有限的区域),但没有什么是有用的...

实际上有一个技巧,因为System.Windows.Forms类可以设计(像往常一样)并在运行时具有正确的行为(例如TabControl).

Answer 1

ParentControlDesigner不知道你想做什么.它只知道您希望UserControl成为容器.

您需要做的是实现自己的设计器,在面板上启用设计模式:

    using System.ComponentModel;
    using System.Windows.Forms;
    using System.Windows.Forms.Design;

    namespace MyCtrlLib
    {
        // specify my custom designer
        [Designer(typeof(MyCtrlLib.UserControlDesigner))]
        public partial class UserControl1 : UserControl
        {
            public UserControl1()
            {
                InitializeComponent();
            }

            // define a property called "DropZone"
            [Category("Appearance")]
            [DesignerSerializationVisibility(DesignerSerializationVisibility.Content)] 
            public Panel DropZone
            {
                get { return panel1; }
            }
        }

        // my designer
        public class UserControlDesigner  : ParentControlDesigner
        {
            public override void Initialize(System.ComponentModel.IComponent component)
            {
                base.Initialize(component);

                if (this.Control is UserControl1)
                {
                    this.EnableDesignMode(
                       (UserControl1)this.Control).DropZone, "DropZone");
                }
            }
        }
    }

我从CodeProject的Henry Minute那里学到了这一点.有关该技术的一些改进,请参阅该链接.