c# - WinForms 设计器在控件更改时删除事件

Question

编辑:我发现了问题并在下面发布了答案!

我在 WinForms 中有一些自定义控件，但我在我的表单上遇到了一个问题，当我在设计器中更改控件时(例如将它向左移动一个像素然后将其移回)，正在处理的每个事件应用于我的控件的已从设计器代码中删除。

例如，对于我的自定义按钮，我没有对 Click 事件做任何特殊的事情。我什至没有在继承 WinForms Button 类的类中触及该属性，但是当我的 Form 中的任何一个控件发生更改时，按钮的单击事件将被删除。

我无法在网上找到与设计者删除事件相关的任何内容，而且我在我的代码中也没有看到任何会导致此类事情发生的内容。

以下是自定义按钮的代码，如果有帮助的话:

CustomVisualButton.cs

using System;
using System.ComponentModel;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Drawing.Text;
using System.Windows.Forms;

namespace CustomVisual {

    [Designer( typeof( CustomVisualControlDesigner ) )]
    public class CustomVisualButton : Button, CustomVisualControlInterface {

        private Boolean _IsHovering = false;

        #region Properties

        [DesignerSerializationVisibility( DesignerSerializationVisibility.Hidden ), Browsable( false )]
        public override Font Font {
            get {
                return base.Font;
            }
            set {
                base.Font = value;
            }
        }

        #endregion

        #region Constructor

        public CustomVisualButton( ) {

            DoubleBuffered = true;
            Font = CustomVisualPalette.DefaultFont;
            SetStyle( ControlStyles.UserPaint, true );
            SetStyle( ControlStyles.SupportsTransparentBackColor, true );
        }

        #endregion

        #region Overrides

        protected override void OnMouseEnter( EventArgs Args ) {

            base.OnMouseEnter( Args );
            _IsHovering = true;
            Cursor = Cursors.Hand;
        }

        protected override void OnMouseLeave( EventArgs Args ) {

            base.OnMouseLeave( Args );
            _IsHovering = false;
            Cursor = Cursors.Default;
        }

        protected override void OnPaint( PaintEventArgs Args ) {
            // long paint method
        }

        protected override void OnResize( EventArgs Args ) {

            base.OnResize( Args );

            if ( CustomVisualPalette.FORCE_HEIGHT > 0 ) {

                Height = CustomVisualPalette.FORCE_HEIGHT;
            }
        }

        #endregion

    }

}

CustomVisualControlInterface.cs

namespace CustomVisual {

    public interface CustomVisualControlInterface {
    }

}

CustomVisualControlDesigner.cs

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

namespace CustomVisual {


    public class CustomVisualControlDesigner : ControlDesigner {

        private DesignerActionListCollection _ActionLists;

        public override DesignerActionListCollection ActionLists {
            get {
                if ( null == _ActionLists ) {
                    _ActionLists = new DesignerActionListCollection( );
                    _ActionLists.Add( new CustomVisualControlActionList( this.Component ) );
                }
                return _ActionLists;
            }
        }

    }

    public class CustomVisualControlActionList : DesignerActionList {

        private Control _Control;
        private DesignerActionUIService _Service = null;

        public CustomVisualControlInterface AlignSubject { get; set; }

        public CustomVisualControlActionList( IComponent Component )
            : base( Component ) {

            _Control = Component as Control;
            _Service = GetService( typeof( DesignerActionUIService ) ) as DesignerActionUIService;

        }

        public void RefreshDesigner( ) {

            _Service.HideUI( _Control );
            _Service.Refresh( _Control );
            _Service.ShowUI( _Control );
        }

        public Int32 SyncHeight( Control Source, Control Destination ) {
            // vertical alignment for elements of possible different height
        }

        public void MatchWidth( ) {
            // makes element width same as subject width
        }

        public void PlaceUnder( ) {
            // places element under subject
        }

        public void PlaceCloseUnder( ) {
            // places element close under subject
        }

        public void PlaceRight( ) {
            // places element right of subject
        }

        public void PlaceCloseRight( ) {
            // places element close right of subject
        }

        public void PlaceAbove( ) {
            // places element above subject
        }

        public void PlaceLeft( ) {
            // places element left of subject
        }

        public void AnchorType1( ) {
            // code to align to certain spot
        }

        public override DesignerActionItemCollection GetSortedActionItems( ) {

            DesignerActionItemCollection Items = new DesignerActionItemCollection( );
            Items.Add( new DesignerActionPropertyItem( "AlignSubject", "Subject", "alignment" ) );
            Items.Add( new DesignerActionMethodItem( this, "MatchWidth", "match width", "alignment" ) );
            Items.Add( new DesignerActionMethodItem( this, "PlaceAbove", "place above", "alignment" ) );
            Items.Add( new DesignerActionMethodItem( this, "PlaceRight", "place right", "alignment" ) );
            Items.Add( new DesignerActionMethodItem( this, "PlaceCloseRight", "place close right", "alignment" ) );
            Items.Add( new DesignerActionMethodItem( this, "PlaceUnder", "place under", "alignment" ) );
            Items.Add( new DesignerActionMethodItem( this, "PlaceCloseUnder", "place close under", "alignment" ) );
            Items.Add( new DesignerActionMethodItem( this, "PlaceLeft", "place left", "alignment" ) );
            Items.Add( new DesignerActionMethodItem( this, "AnchorType1", "anchor type 1", "anchors" ) );
            return Items;

        }

    }
}

Answer 1

确保当您编辑设计器生成的代码时，您的编辑方式使其可以读取并重新序列化。在这种情况下，设计师正在寻找:

control.Click += new System.EventHandler(this.methodname)

但我给了它:

control.Click += this.methodname

虽然它工作得很好，但当设计器被编辑和重新序列化时，它无法解析我所做的并只是将其删除。

我发现我的错误是让设计器生成一个事件，那时我注意到它制作的代码和我给它的代码是不同的。如果您遇到类似的问题，那么我建议让设计人员生成与您正在做的事情类似的东西，然后将其用作指南。