Question

我想创建一个用户可以放置元素的应用程序。

这是我的问题：我想按下一个按钮（向下移动），并且在移动鼠标时，该按钮应该随鼠标移动而移动。

如何在c# WPF中对此进行编程？我必须使用“保证金”属性吗？

致谢

Answer 1

MainWindow.xaml.cs：

    group_id  words   ID
1        1  beach vacation
2        1   sand vacation
3        1   trip vacation
4        1   warm vacation
5        2 travel  meeting
6        1  water vacation
7        2  beach  meeting
8        3   sand   onduty

MainWindow.xaml：

namespace dragdropButton
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        /// Tells whether the button is being pressed or not
        private bool buttonPressed;

        #region Imports method to determinate the mouse position
        [DllImport("user32.dll")]
        [return: MarshalAs(UnmanagedType.Bool)]
        internal static extern bool GetCursorPos(ref Win32Point pt);

        [StructLayout(LayoutKind.Sequential)]
        internal struct Win32Point
        {
            public Int32 X;
            public Int32 Y;
        };

        /// <summary>
        /// Obtains the mouse current position
        /// </summary>
        /// <returns>Position coordinates</returns>
        public static Point GetMousePosition()
        {
            Win32Point w32Mouse = new Win32Point();
            GetCursorPos(ref w32Mouse);
            return new Point(w32Mouse.X, w32Mouse.Y);
        }
        #endregion

        public MainWindow()
        {
            InitializeComponent();
        }

        /// <summary>
        /// Calculates the distance between two 2-dimensional points A and B
        /// </summary>
        /// <param name="pt">Point A</param>
        /// <param name="x">X coordinate of B</param>
        /// <param name="y">Y coordinate of B</param>
        /// <returns></returns>
        private double EuclideanDist(Point pt, double x, double y)
        {
            return Math.Sqrt(Math.Pow(pt.X - x, 2) + Math.Pow(pt.Y - y, 2));
        }

        /// <summary>
        /// Maps the left margin to the current mouse position
        /// </summary>
        /// <param name="pt">Mouse current position</param>
        /// <returns>Left margin</returns>
        private double GetLeftMargin(Point pt)
        {
            double x = 0;
            double y = pt.Y;
            return EuclideanDist(pt, x, y);
        }

        /// <summary>
        /// Maps the top margin to the current mouse position
        /// </summary>
        /// <param name="pt">Mouse current position</param>
        /// <returns>Top margin</returns>
        private double GetTopMargin(Point pt)
        {
            double x = pt.X;
            double y = 0;
            return EuclideanDist(pt, x, y);
        }

        /// <summary>
        /// Fires when mouse moves within this WPF window
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void Window_PreviewMouseMove(object sender, MouseEventArgs e)
        {
            // if button is being pressed
            if (buttonPressed)
            {
                // get the mouse current position
                Point pt = GetMousePosition();

                // set the new button position
                this.button.Margin = new Thickness(GetLeftMargin(pt), GetTopMargin(pt), 0, 0);
            }
        }

        /// <summary>
        /// Fires whe button is pressed by mouse right click
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void button_MouseDown(object sender, MouseButtonEventArgs e)
        {
            buttonPressed = true;
        }

        /// <summary>
        /// Firew when the button is released by mouse right click
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void button_MouseUp(object sender, MouseButtonEventArgs e)
        {
            buttonPressed = false;
        }
    }
}

按下按钮并将其拖到屏幕上

1 个答案: