C# WinForm - 将图片框从一个 GroupBox 拖放到另一个 [重复]

Question

如果已经问过这个问题，我提前道歉。搜索 stackoverflow 和互联网并没有提供任何有用的示例。

在正在运行的程序中，我有一个图片框，我需要能够单击并从一个 GroupBox 拖动到另一个。我知道如何在 WinForm 本身周围拖动图片框（即不涉及任何 GroupBoxes）。 我找不到任何有关如何执行此操作的示例。

我已经为每个似乎与分组框/鼠标交互相关的事件创建了代码（代码见帖子末尾）。

注意：感谢您对需要代码的反馈。我是新的 Stack Overflow。

界面： Initial Interface

问题： 当我单击 pbxMoveIt 并将其拖到组框上时，根据状态标签中的文本，组框事件永远不会触发。

Dragging image over group box doesn't trigger group box enter, hover or other events

当我移动鼠标而不拖动任何东西时，会触发组框鼠标悬停事件。

Group box mouse hover event fires when not dragging anything.

添加代码：

namespace MoveControlsOnFormBetweenGroupBoxes {
    public partial class frmMain : Form {

        private Point m_MouseDownLocation;
        private bool m_IsDragging;

        public frmMain ( ) {
            InitializeComponent ( );

            pbxMoveIt.BringToFront ( );
            gbx1.AllowDrop = true;
            gbx2.AllowDrop = true;
            lblStatus.Text = "GUI Status: Started";
        }

        #region Picture Box Related Methods
        // Picture Related Methods
        private void pbxMoveIt_MouseDown ( object sender, MouseEventArgs e ) {
            lblStatus.Text = "GUI Status: pbxMoveIt - MouseDown";
            if ( e.Button == MouseButtons.Left ) {
                m_MouseDownLocation = e.Location;
                m_IsDragging = true;
            }
        }
        private void pbxMoveIt_MouseMove ( object sender, MouseEventArgs e ) {
            int newX;
            int newY;
            int minX = 10;
            int minY = 10;
            int maxX = this.Width - (25 + pbxMoveIt.Width);
            int maxY = this.Height - (45 + pbxMoveIt.Height);
            if ( e.Button == MouseButtons.Left ) {
                lblStatus.Text = "GUI Status: pbxMoveIt - MouseMove";
                newX = e.X + pbxMoveIt.Left - m_MouseDownLocation.X;
                newY = e.Y + pbxMoveIt.Top - m_MouseDownLocation.Y;
                if ( m_IsDragging ) {
                    if ( ( newX >= minX ) && ( newX <= maxX ) ) {
                        pbxMoveIt.Left = newX;
                    }
                    if ( ( newY >= minY ) && ( newY <= maxY ) ) {
                        pbxMoveIt.Top = newY;
                    }
                }
            }
        }
        private void pbxMoveIt_MouseUp ( object sender, MouseEventArgs e ) {
            lblStatus.Text = "GUI Status: pbxMoveIt - MouseUp";
            if ( e.Button == System.Windows.Forms.MouseButtons.Left ) {
                m_IsDragging = false;
            }
        }
        #endregion

        #region Group Box Related
        // Group Box Related Methods
        private string Gbx_Title ( object sender ) {
            string boxTitle = "Unknown";
            if ( sender == gbx1 ) {
                boxTitle = "Group Box 1";
            }
            if ( sender == gbx2 ) {
                boxTitle = "Group Box 2";
            }
            return boxTitle;
        }
        private void gbx_DragDrop ( object sender, DragEventArgs e ) {
            lblStatus.Text = String.Format ( "GUI Status: {0} - DragDrop", Gbx_Title ( sender ) );
        }
        private void gbx_DragEnter ( object sender, DragEventArgs e ) {
            lblStatus.Text = String.Format ( "GUI Status: {0} - DragEnter", Gbx_Title ( sender ) );
        }
        private void gbx_DragLeave ( object sender, EventArgs e ) {
            lblStatus.Text = String.Format ( "GUI Status: {0} - DragLeave", Gbx_Title ( sender ) );
        }

        private void gbx_DragOver ( object sender, DragEventArgs e ) {
            lblStatus.Text = String.Format ( "GUI Status: {0} - DragOver", Gbx_Title ( sender ) );
        }

        private void gbx_Enter ( object sender, EventArgs e ) {
            lblStatus.Text = String.Format ( "GUI Status: {0} - Enter", Gbx_Title ( sender ) );
        }

        private void gbx_Leave ( object sender, EventArgs e ) {
            lblStatus.Text = String.Format ( "GUI Status: {0} - Leave", Gbx_Title ( sender ) );
        }

        private void gbx_MouseHover ( object sender, EventArgs e ) {
            lblStatus.Text = String.Format ( "GUI Status: {0} - MouseHover", Gbx_Title ( sender ) );
        }
        #endregion
    }
}

Answer 1

将我的课程添加到您的项目中

using System;
using System.Windows.Forms;

namespace Hector.Framework.Utils
{
    public class Drag : Form
    {
        private bool isDraggable;
        private Control target;
        private int a, b;

        public Drag(){}

        public void Grab(Control control)
        {
            try
            {
                this.isDraggable = true;
                this.target = control;
                this.a = Control.MousePosition.X - this.target.Left;
                this.b = Control.MousePosition.Y - this.target.Top;
            }
            catch(Exception ex)
            {
                throw new Exception(ex.Message);
            }
        }

        public void MoveObject(bool Horizontal = true, bool Vertical = true)
        {
            try
            {
                if (this.isDraggable)
                {
                    int x = Control.MousePosition.X,
                        y = Control.MousePosition.Y;

                    if (Horizontal)
                    {
                        this.target.Left = x - this.a;
                    }
                    if (Vertical)
                    {
                        this.target.Top = y - this.b;
                    }
                }
            }
            catch (Exception ex)
            {
                throw new Exception(ex.Message);
            }
        }

        public void Release()
        {
            this.isDraggable = false;
        }
    }
}

然后，调用 PictureBox 事件

    public partial class Form1 : Form
    {
    private Hector.Framework.Utils.Drag drag = new Hector.Framework.Utils.Drag();

    private void pictureBox_MouseDown(object sender, MouseEventArgs e)
    {
       drag.Grab(pictureBox);
    }

    private void pictureBox_MouseUp(object sender, MouseEventArgs e)
    {
       drag.Release();
    }

    private void pictureBox_MouseMove(object sender, MouseEventArgs e)
    {
       drag.MoveObject();
    }
    }