C# 拖动时比较WinForms控件的位置

我有一个小程序，其中包含一个名为

button1

的按钮和一个名为

panel1

的面板，该面板的颜色为绿色。到目前为止，该程序允许您在表单周围拖动

按钮1

。我正在尝试扩展此程序，因此当面板上的

按钮1

被删除时，面板将变为红色

表格：

迄今为止的守则：

System.Drawing.Point OldPosition; 

public Form1()
{
    InitializeComponent();
}

private void button1_MouseDown(object sender, MouseEventArgs e)
{
    //Only prepare if the button click down is the left button  
    if (e.Button == MouseButtons.Left)
    {
        //Store the current mouse location  
        OldPosition = e.Location;
        //Change the mouse cursor if you want  
        button1.Cursor = Cursors.Hand;
    }  
}

private void button1_MouseMove(object sender, MouseEventArgs e)
{
    //Only move if the left button still down  
    if (e.Button == MouseButtons.Left)
    {
        button1.Location = new Point(button1.Location.X + (e.X - OldPosition.X), button1.Location.Y + (e.Y - OldPosition.Y));
    } 
}

private void Form1_Load(object sender, EventArgs e)
{
    panel1.BackColor = Color.Green;        
}

private void panel1_MouseEnter(object sender, EventArgs e)
{
    if (button1.Location == panel1.Location)
        panel1.BackColor = Color.Red; //im not sure how to do this part
}

请尝试以下代码：

private void button1_MouseMove(object sender, MouseEventArgs e)
{
    //Only move if the left button still down  
    if (e.Button == MouseButtons.Left)
    {
        button1.Location = new Point(button1.Location.X + (e.X - OldPosition.X), button1.Location.Y + (e.Y - OldPosition.Y));

        //CHECK IF NEW LOCATION IS WITHIN PANEL BOUNDS
        if (panel1.Bounds.Contains(button1.Location))
           panel1.BackColor = Color.Red;
        else
           panel1.BackColor = Color.Green;
    }
}

此外，在designer中，您可能需要将

panel1

控件“发送到后面”，否则按钮在面板上方将不可见