WinFrom 界面上实现拖拽效果 TreeView

怼烎@ 2022-07-16 13:10 166阅读 0赞

最近应付演示用WinFrom做了个CS客户端，其中有个功能需要实现拖拽功能，如下图：![Center][]

左边是个摄像枪列表，右边要显示视频。

要求从左边树列表中可以拖拽摄像枪到对应的窗口显示视频。

经过查找资料，具体实现如下：

1，给源控件（即TreeView）添加ItemDrag事件，让其可以拖动。

![Center 1][]

private void tv_CameraList_ItemDrag(object sender, ItemDragEventArgs e)
            {
                //非叶子节点不可拖动
                if (!string.IsNullOrEmpty(((TreeNode)e.Item).Name))
                {
                    DoDragDrop(e.Item, DragDropEffects.Move);
                }
            }

2,给目标控件（这里用是PictureBox控件）添加DragDrop和DragEnter事件

![Center 2][]

private void pb_41_DragDrop(object sender, DragEventArgs e)
            {
                pb_41.Image = null;
    
                TreeNode a = (TreeNode)e.Data.GetData(typeof(TreeNode));
    
                Camera camera = cameraList.Where(o => o.Id == a.Name).FirstOrDefault();//获取摄像枪信息
    
                 try
                 {
                        if (m_lRealHandle41 >= 0)
                        {
                            CHCNetSDK.NET_DVR_StopRealPlay(m_lRealHandle41);//关闭之前的预览
                            m_lRealHandle41 = -1;
                        }
    
                        m_LWHandle41 = cameraHandler.ConnectionCamera(camera.IP, 0, pb_41.Handle);
                        if (m_LWHandle41 != IntPtr.Zero)
                        {
                            bool flg = cameraHandler.OpenCamera(m_LWHandle41);
                            if (!flg)
                            {
                                MessageBox.Show("预览失败");
                            }
                        }
                        else
                        {
                            MessageBox.Show("预览失败");
                        }
                    }
                    catch (Exception ex)
                    {
    
                        LogHelper.Error(ex);
                    }
    
            }

private void pb_41_DragEnter(object sender, DragEventArgs e)
            {
                if (m_CurrentModel == 4)
                {
                    if (e.Data.GetDataPresent(typeof(TreeNode)))
                        e.Effect = DragDropEffects.Move;
                    else
                        e.Effect = DragDropEffects.None;
                }
            }

3，初始化时设置PictureBox的AllowDrop属性为true

private void Init()
            {
                pb_1.AllowDrop = true;
                pb_41.AllowDrop = true;
                pb_42.AllowDrop = true;
                pb_43.AllowDrop = true;
                pb_44.AllowDrop = true;
            }

[Center]: /images/20220715/761300340b314a2da4f654a582ad9ef2.png
[Center 1]: /images/20220715/4afcf4f9f4984aac896144ce7f664a10.png
[Center 2]: /images/20220715/58801812f635418aafbcbd19939612e5.png