用父窗体移动子窗体

我有两个窗体:一个父窗体和一个支持子窗体。

当子窗体最初显示时，我设置了所谓的"零点"，这是子窗体相对于父窗体的位置，并由父窗体上的一个控件定义:

    private void miShowChild_Click(object sender, EventArgs e) {
        if ((m_childForm == null) || m_childForm .IsDisposed) {
            m_formLeft = this.Left + this.Control1.Left;
            m_formTop = this.Top + this.Control1.Top;
            m_childForm = new ChildForm1();
            m_childForm.Show(this);
            m_childForm.Parent_Shift(m_formTop, m_formLeft);
        }
        m_roleMap.TopLevel = true;
    }

当父窗体移动到其他地方时，该信息被转换为子窗体:

    private void Form1_MoveResize(object sender, EventArgs e) {
        if ((m_childForm != null) && !m_childForm.IsDisposed) {
            m_formLeft = this.Left + this.Control1.Left;
            m_formTop = this.Top + this.Control1.Top;
            m_childForm.Parent_Shift(m_formTop, m_formLeft);
        }
    }

这个逻辑似乎没问题，对吧?

那么，Child表单中发生了什么呢?

首先，我定义了这些变量:

    private bool m_automate;
    private int m_left, m_top;
    private Point m_zero;
    private void ChildForm_Load(object sender, EventArgs e) {
        m_left = 0;
        m_top = 0;
        m_zero = Point.Empty;
    }

当使用Parent_Shift设置Child时，我想要得到这个"零点"应该定义的地方:

    public void Parent_Shift(int parentTop, int parentLeft) {
        m_automate = true;
        if (m_zero != Point.Empty) {
            this.Left = parentLeft - m_left;
            this.Top = parentTop - m_top;
        } else {
            this.Left = parentLeft;
            this.Top = parentTop;
        }
        m_zero = new Point(this.Left, this.Top);
        m_automate = false;
    }

当子窗体被重新定位时，而不是因为父窗体移动，然后我想记录离我的"零点"有多远:

    private void Form_MoveResize(object sender, EventArgs e) {
        if (!m_automate && this.Visible) {
            if (m_zero != Point.Empty) {
                m_left = m_zero.X - this.Left;
                m_top = m_zero.Y - this.Top;
            } else {
                m_zero = new Point(this.Left, this.Top);
            }
        }
    }

所有的方法都在启动，但我似乎无法弄清楚坐标系统。

我可以手动移动子窗体，然后移动父窗体和子窗体翘曲到其他位置-然后与父窗体成比例移动。

我希望子元素保持在相对于父元素的某个(X, Y)坐标上。

当子窗体被移动时，该相对坐标需要更新为子窗体离开时的位置。

有人知道如何解决我的问题吗?

public partial class ParentForm : Form
{
    private bool updatingChildPosition = false;
    private Point childFormOffset = Point.Empty;
    private ChildForm child = null;
    public ParentForm()
    {
        InitializeComponent();
        this.child = new ChildForm();
        child.Show();
        child.Move += child_Move;
        UpdateChildFormOffset();
    }
    void child_Move(object sender, EventArgs e)
    {
        // Child form is moved, store it's new offset
        UpdateChildFormOffset();
    }
    private void UpdateChildFormOffset()
    {
        if (!updatingChildPosition)
        {
            this.childFormOffset = new Point(
                this.child.Location.X - this.Location.X,
                this.child.Location.Y - this.Location.Y);
        }
    }
    private void ParentForm_Move(object sender, EventArgs e)
    {
        // Updating child position
        this.updatingChildPosition = true;
        child.Location = new Point(
            this.Location.X + childFormOffset.X,
            this.Location.Y + childFormOffset.Y);
        this.updatingChildPosition = false;
    }
}