UserControl 的子项在移动后消失

Question

我遇到了一个很严重的问题。我通过使用 MouseDown, MouseMove,MouseUp 事件在其父项中创建了一个可移动的 UserControl（如 window）。 [Designer("System.Windows.Forms.Design.ParentControlDesigner, System.Design", typeof(IDesigner))] 属性用于我可以在 VS 的设计器中向此 UserControl 添加控件。

州：

移动这些 UserControl 效果很好（Usercontrol 按预期移动...）
可以在 VS 的设计器中添加控件，并在运行时按设计显示[可见，应该如此]
通过移动 UserControl，子项变得不可见，但 .Visible=true 没有改变
.BringToFront(); 没有影响（我以为他们可能在容器后面）

这是用户控件 class:

  [Designer("System.Windows.Forms.Design.ParentControlDesigner, System.Design", typeof(IDesigner))]
    public partial class MovableContainer : UserControl
    {
        bool mdown = false;
        Point mpos;
        [EditorBrowsable(EditorBrowsableState.Always)]
        [SettingsBindable(true)]
        [DesignerSerializationVisibility(DesignerSerializationVisibility.Content)]
        public Axis Rasta { get; set; }
        public static int DefautlRasta = 10;
        public MovableContainer()
        {
            rasta = DefautlRasta;
            InitializeComponent();
            this.MouseDown += ((object o, MouseEventArgs e) =>
            {
                mdown = true;
                mpos = this.PointToClient(MousePosition);
            });
            this.MouseUp += ((object o, MouseEventArgs e) => mdown = false);
            this.MouseMove += MovableContainer_MouseMove;
            this.Paint += (object o, PaintEventArgs e) =>
            {
                Console.WriteLine("BTF");
                this.Parent.Controls.OfType<Control>().ToList().ForEach(x => x.BringToFront());
                this.Controls.OfType<Control>().ToList().ForEach(x => x.BringToFront());
                this.Controls.OfType<Control>().ToList().ForEach(x => x.Show());

            };

            this.ParentChanged += ((object o, EventArgs e) =>
                {
                    if (this.Parent == null)
                    {
                        try { this.Parent.SizeChanged -= Parent_SizeChanged; }
                        catch { }
                    }
                    else
                    {
                        try { this.Parent.SizeChanged += Parent_SizeChanged; }
                        catch { }
                    }
                }
                );

            // this.KeyDown += ((object o, KeyEventArgs e) => {
            ///kdown = (RastaKey == e.KeyCode); Console.WriteLine("K:"+kdown);
            //});

            //this.KeyUp += ((object o, KeyEventArgs e) => kdown = false);
        }

        void Parent_SizeChanged(object sender, EventArgs e)
        {
            this.Boundis = new Rectangle(Parent.Padding.Left, Parent.Padding.Top, Parent.Size.Width - Parent.Padding.Horizontal, Parent.Size.Height - Parent.Padding.Vertical);
            {
                this.Location = this.Location.Add(this.PointToClient(MousePosition).Sub(mpos)).Rasta(Rasta, rasta);
                Rectangle rct = new Rectangle(this.Location, this.Size);
                if (this.Boundis.X > rct.X)
                {
                    this.Location = new Point(this.Boundis.X, this.Location.Y);
                    Console.Write("R");
                }
                //left
                if (this.Boundis.Right < rct.Right)
                {
                    this.Location = new Point(this.Boundis.Right - rct.Width, rct.Y);
                    Console.Write("L");
                }
                //top
                if (this.Boundis.Y > rct.Y)
                {
                    this.Location = new Point(rct.X, this.Boundis.Y);
                    Console.Write("T");
                }
                //bottom
                if (this.Boundis.Bottom < rct.Bottom)
                {
                    this.Location = new Point(rct.X, this.Boundis.Bottom - rct.Height);
                    Console.Write("B");

                }
                Console.WriteLine();
            }
        }


        void MovableContainer_MouseMove(object sender, MouseEventArgs e)
        {
            if (mdown)
            {
                this.Location = this.Location.Add(this.PointToClient(MousePosition).Sub(mpos)).Rasta(Rasta, rasta);
                Rectangle rct = new Rectangle(this.Location, this.Size);
                if (this.Boundis.X > rct.X)
                {
                    this.Location = new Point(this.Boundis.X, this.Location.Y);
                    Console.Write("R");
                }
                //left
                if (this.Boundis.Right < rct.Right)
                {
                    this.Location = new Point(this.Boundis.Right - rct.Width, rct.Y);
                    Console.Write("L");
                }
                //top
                if (this.Boundis.Y > rct.Y)
                {
                    this.Location = new Point(rct.X, this.Boundis.Y);
                    Console.Write("T");
                }
                //bottom
                if (this.Boundis.Bottom < rct.Bottom)
                {
                    this.Location = new Point(rct.X, this.Boundis.Bottom - rct.Height);
                    Console.Write("B");

                }
                Console.WriteLine();

            }

        }
        public Rectangle Boundis { get; set; }

    }
    public enum Axis { X, Y, None }

那么，我该如何解决这个问题？

Answer 1

坦率地说，您发布的代码一团糟 - 您放在那里的大部分内容都没有意义。据我所知，您正在尝试实现运行时间可移动容器并进行剪裁。一个简单的继承 Panel 会做同样的事情 w/o 那些设计器属性等的需要。无论如何，你描述的问题是由你的 Parent_SizeChanged 处理程序中的错误计算引起的。这是一段经过部分清理的代码，它可以执行我认为您正在尝试执行的操作 w/o 遇到任何问题：

[Designer("System.Windows.Forms.Design.ParentControlDesigner, System.Design", typeof(IDesigner))]
public partial class MovableContainer : UserControl
{
    bool mdown = false;
    Point mpos;
    int rasta;
    Control parent;

    [EditorBrowsable(EditorBrowsableState.Always)]
    [SettingsBindable(true)]
    [DesignerSerializationVisibility(DesignerSerializationVisibility.Content)]
    public Axis Rasta { get; set; }
    public static int DefautlRasta = 10;
    public MovableContainer()
    {
        rasta = DefautlRasta;
        InitializeComponent();
        this.MouseDown += (sender, e) =>
        {
            mdown = true;
            mpos = e.Location;
        };
        this.MouseUp += (sender, e) =>
        {
            mdown = false;
        };
        this.MouseMove += (sender, e) =>
        {
            if (mdown)
                SetLocation(this.Location.Add(e.Location.Sub(mpos)).Rasta(Rasta, rasta));
        };
        EventHandler onParentSizeChanged = (sender, e) =>
        {
            SetLocation(this.Location);
        };
        this.ParentChanged += (sender, e) =>
        {
            if (parent != null) parent.SizeChanged -= onParentSizeChanged;
            parent = Parent;
            if (parent != null) parent.SizeChanged += onParentSizeChanged;
        };
    }
    private void SetLocation(Point location)
    {
        var rect = new Rectangle(location, Size);
        var clipRect = Parent.DisplayRectangle;
        if (rect.Right > clipRect.Right) rect.X -= (rect.Right - clipRect.Right);
        if (rect.X < clipRect.X) rect.X = clipRect.X;
        if (rect.Bottom > clipRect.Bottom) rect.Y -= (rect.Bottom - clipRect.Bottom);
        if (rect.Y < clipRect.Y) rect.Y = clipRect.Y;
        location = rect.Location;
        if (this.Location == location) return;
        this.Location = location;
    }

}
public enum Axis { X, Y, None }
// You haven't provided these, so I'm guessing by the usage 
static class Utils
{
    public static Point Add(this Point left, Point right)
    {
        return new Point(left.X + right.X, left.Y + right.Y);
    }
    public static Point Sub(this Point left, Point right)
    {
        return new Point(left.X - right.X, left.Y - right.Y);
    }
    public static Point Rasta(this Point pt, Axis axis, int value)
    {
        // Have absolutely no idea what is this about
        return pt;
    }
}

UserControl 的子项在移动后消失

Children of a UserControl disappear after moving

c#

user-controls

winforms