c# – 用户控制停靠属性

ControlDesigner：

public class MyUserControlDesigner : ControlDesigner
{

    private DesignerActionListCollection _actionLists;
    public override System.ComponentModel.Design.DesignerActionListCollection ActionLists
    {
        get
        {
            if (_actionLists == null)
            {
                _actionLists = new DesignerActionListCollection();
                _actionLists.Add(new MyUserControlActionList(this));
            }
            return _actionLists;
        }
    }
}

DesignerActionList：

public class MyUserControlActionList : DesignerActionList
{
    public MyUserControlActionList(MyUserControlDesigner designer) : base(designer.Component) { }

    public override DesignerActionItemCollection GetSortedActionItems()
    {
        DesignerActionItemCollection items = new DesignerActionItemCollection();
        items.Add(new DesignerActionPropertyItem("DockInParent","Dock in parent"));
        return items;
    }

    public bool DockInParent
    {
        get
        {
            return ((MyUserControl)base.Component).Dock == DockStyle.Fill;
        }
        set
        {
            TypeDescriptor.GetProperties(base.Component)["Dock"].SetValue(base.Component,value ? DockStyle.Fill : DockStyle.None);
        }
    }    
}

最后,您需要将设计师附加到您的控件：

[Designer("NamespaceName.MyUserControlDesigner,AssemblyContainingTheDesigner")]
public partial class MyUserControl : UserControl
{
    // all the code for your control

简要说明

该控件具有与之关联的Designer属性,指出了我们的自定义设计器.该设计器中唯一的自定义是公开的DesignerActionList.它会创建自定义操作列表的实例,并将其添加到公开的操作列表集合中.

自定义操作列表包含bool属性(DockInParent),并为该属性创建操作项.如果正在编辑的组件的Dock属性是DockStyle.Fill,则属性本身将返回true,否则为false,如果DockInParent设置为true,则组件的Dock属性设置为DockStyle.Fill,否则为DockStyle.None.

这将在设计器中显示靠近控件右上角的小“动作箭头”,然后单击箭头将弹出任务菜单.