R_D_Demo/WpfNodeTest/WpfNodeTest/Views/NodeTemplateControl.xaml.cs

using System;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Input;
using WpfNodeTest.Models;

namespace WpfNodeTest.Views
{
    /// <summary>
    /// 节点模板控件
    /// </summary>
    public partial class NodeTemplateControl : UserControl
    {
        private Point _startPoint;
        private bool _isDragging;

        public NodeTemplateControl()
        {
            InitializeComponent();
            PreviewMouseLeftButtonDown += OnPreviewMouseLeftButtonDown;
            PreviewMouseMove += OnPreviewMouseMove;
        }

        // 记录鼠标按下位置
        private void OnPreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
        {
            _startPoint = e.GetPosition(null);
            _isDragging = false;
        }

        // 鼠标移动时启动拖放
        private void OnPreviewMouseMove(object sender, MouseEventArgs e)
        {
            if (e.LeftButton == MouseButtonState.Pressed && !_isDragging)
            {
                Point currentPosition = e.GetPosition(null);
                Vector diff = _startPoint - currentPosition;

                // 移动超过阈值才启动拖拽
                if (Math.Abs(diff.X) > SystemParameters.MinimumHorizontalDragDistance ||
                    Math.Abs(diff.Y) > SystemParameters.MinimumVerticalDragDistance)
                {
                    _isDragging = true;
                    if (DataContext is NodeTypeInfo nodeType)
                    {
                        System.Diagnostics.Debug.WriteLine($"启动拖拽: {nodeType.TypeName}");
                        DragDrop.DoDragDrop(this, nodeType, DragDropEffects.Copy);
                    }
                    else
                    {
                        System.Diagnostics.Debug.WriteLine("DataContext不是NodeTypeInfo类型");
                    }
                }
            }
        }
    }
}