wpf之DragDrop研究

最新推荐文章于 2025-02-19 15:14:13 发布

g0415shenw

最新推荐文章于 2025-02-19 15:14:13 发布

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分类专栏： wpf

本文链接：https://blog.youkuaiyun.com/g0415shenw/article/details/104114286

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想要实现一个效果，当鼠标拖拽的时候，有一个跟随的窗口，随着鼠标移动。

相关步骤如下：

1，启动拖拽

            DataObject dataobj = new DataObject("1");
            DragDrop.DoDragDrop(DirectoryTree, dataobj, DragDropEffects.Move);

2，创建一个窗体

            _Drag = new Window_Drag
            {
                Topmost = true,
                WindowStartupLocation = WindowStartupLocation.Manual
            };

            var pt = Mouse.GetPosition(null);
            _Drag.Top = pt.Y + DataCenter.Ins().FrameWindow.Top;
            _Drag.Left = pt.X + DataCenter.Ins().FrameWindow.Left;
            _Drag.ResName = Name;
            _Drag.ResId = ResId;

            _Drag.Show();

3，添加窗体跟随鼠标移动

添加拖拽移动事件

RealPlayGrid.AddHandler(DragOverEvent, new DragEventHandler(RealPlay_Vm.Grid_DragOver), true);

设置窗口的位置：

            if (null != _Drag)
            {
                if (!PeHostWin32.GetCursorPos(out PeHostWin32.POINT p))
                {
                    return;
                }
                Point relativePos = DataCenter.Ins().FrameWindow.PointFromScreen(new System.Windows.Point(p.X,p.Y));
                _Drag.Left = DataCenter.Ins().FrameWindow.Left+ relativePos.X;
                _Drag.Top = DataCenter.Ins().FrameWindow.Top + relativePos.Y;
            }

这里用到了一个windows api 获取鼠标的实时位置

public class PeHostWin32
    {
        [StructLayout(LayoutKind.Sequential)]
        public struct POINT
        {
            public int X;
            public int Y;

            public POINT(int x, int y)
            {
                this.X = x;
                this.Y = y;
            }
        }

        public static Int32 GWL_EXSTYLE = -20;
        public static Int32 WS_EX_LAYERED = 0x00080000;
        public static Int32 WS_EX_TRANSPARENT = 0x00000020;


        [DllImport("user32.dll", CharSet = CharSet.Auto)]
        public static extern bool GetCursorPos(out POINT pt);

        [DllImport("user32.dll", CharSet = CharSet.Auto)]
        public static extern Int32 GetWindowLong(IntPtr hWnd, Int32 nIndex);

        [DllImport("user32.dll", CharSet = CharSet.Auto)]
        public static extern Int32 SetWindowLong(IntPtr hWnd, Int32 nIndex, Int32 newVal);
    }

****************************************最后居然发现一个问题************************************

DragDrop.DoDragDrop(DirectoryTree, dataobj, DragDropEffects.Move);

上面这个函数居然是阻塞的，等拖拽执行完，才会继续往下执行。