关于mouse_enter 和 mouse_leave的问题

Question

我有一个form1，其上有一个btn1，现在我的需求是当鼠标在form1上时，btn1显示，当鼠标移出form1上时，btn1隐藏。 但是出现一个问题，当鼠标移至btn1上时，触发了mouse_leave事件，以至于把btn1隐藏了。 请问该问题如何解决?

Answer 1

 public partial class Form1 : Form
    {
        Point p; int h, w;
        public Form1()
        {
            InitializeComponent();
           
        }
      
                  private void Form1_MouseLeave(object sender, EventArgs e)
        {

                    if (MousePosition.X > PointToScreen(button1.Location).X && MousePosition.X < PointToScreen(button1.Location).X + w && MousePosition.Y > PointToScreen(button1.Location).Y
                && MousePosition.Y < PointToScreen(button1.Location).Y + h)
            {
                button1.Visible = true;
            }
            else { button1.Visible = false; }
        }

        private void Form1_MouseEnter(object sender, EventArgs e)
        {
            button1.Visible = true;
        }

           private void Form1_Load(object sender, EventArgs e)
        {
            p = button1.Location; h = button1.Height; w = button1.Width;
           
        }
    }

 

//我测试过能达到预期效果，或有不足，欢迎指出

Answer 2

你好！

我用了一个延时的小技巧解决了你的问题，参考下面的代码：

using System.ComponentModel;
using System.Windows.Forms;

namespace WindowsFormsApplication1
{
  public partial class Form1 : Form
  {
    public Form1()
    {
      InitializeComponent();
      InitializeDemo();
    }

    bool HasLeveButton = true;
    void InitializeDemo()
    {
      Button btn = new Button() { Text = "Sample Button", Visible = false, Dock = DockStyle.Fill };

      this.Controls.Add(btn);
      this.Padding = new Padding(20);

      this.MouseEnter += (o, e) => { btn.Visible = true; };
      this.MouseLeave += (o, e) => { DelayHide(btn); };

      btn.MouseEnter += (o, e) => { HasLeveButton = false; };
      btn.MouseLeave += (o, e) => { HasLeveButton = true; };
    }

    /// <summary>
    /// 延时隐藏
    /// </summary>
    void DelayHide(Control control)
    {
      using (BackgroundWorker bg = new BackgroundWorker())
      {
        bg.DoWork += (o, e) => { System.Threading.Thread.Sleep(5); };
        bg.RunWorkerCompleted += (o, e) =>
        {
          if (HasLeveButton)
            control.Visible = false;
        };
        bg.RunWorkerAsync();
      }
    }
  }
}

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