移动没有标题栏的表单

本文关键字：表单 标题栏 移动 | 更新日期: 2023-09-27 18:05:56

我有一个没有标题栏的窗体。我想用鼠标拖动它。在互联网上搜索后，我找到了移动表单的代码:

protected override void WndProc(ref Message m)
{
    switch (m.Msg)
    {
        case 0x84:
            base.WndProc(ref m);
            if ((int)m.Result == 0x1)
                m.Result = (IntPtr)0x2;
            return;
    }
base.WndProc(ref m);
}

但是它有一个问题:它只作用于没有被任何控件覆盖的窗体区域。例如，如果我使用标签或组框，我不能通过点击它们来移动表单。
我该如何解决这个问题?

移动没有标题栏的表单

一种方法是这样实现IMessageFilter。

public class MyForm : Form, IMessageFilter
{
    public const int WM_NCLBUTTONDOWN = 0xA1;
    public const int HT_CAPTION = 0x2;
    public const int WM_LBUTTONDOWN = 0x0201;
    [DllImportAttribute("user32.dll")]
    public static extern int SendMessage(IntPtr hWnd, int Msg, int wParam, int lParam);
    [DllImportAttribute("user32.dll")]
    public static extern bool ReleaseCapture();
    private HashSet<Control> controlsToMove = new HashSet<Control>();
    public MyForm()
    {
        Application.AddMessageFilter(this);
        controlsToMove.Add(this);
        controlsToMove.Add(this.myLabel);//Add whatever controls here you want to move the form when it is clicked and dragged
    }
    public bool PreFilterMessage(ref Message m)
    {
       if (m.Msg == WM_LBUTTONDOWN &&
            controlsToMove.Contains(Control.FromHandle(m.HWnd)))
        {
            ReleaseCapture();
            SendMessage(this.Handle, WM_NCLBUTTONDOWN, HT_CAPTION, 0);
            return true;
        }
        return false;
    }
}

这基本上就是你要做的:

使无边框的窗体可移动?

您可能能够将相同的代码添加到窗体上其他控件的鼠标按下事件以完成相同的事情。

让无边框的表单可移动?

public const int WM_NCLBUTTONDOWN = 0xA1;
public const int HT_CAPTION = 0x2;
[System.Runtime.InteropServices.DllImportAttribute("user32.dll")]
public static extern int SendMessage(IntPtr hWnd, int Msg, int wParam, int lParam);
[System.Runtime.InteropServices.DllImportAttribute("user32.dll")]
public static extern bool ReleaseCapture();
private void Form1_MouseDown(object sender, System.Windows.Forms.MouseEventArgs e)
{     
    if (e.Button == MouseButtons.Left)
    {
        ReleaseCapture();
        SendMessage(Handle, WM_NCLBUTTONDOWN, HT_CAPTION, 0);
    }
}

当用户将鼠标按在表单中的lblMoveForm Label上时，执行以下事件处理程序。

     // On left button, let the user drag the form.
private void lblMoveForm_MouseDown(object sender, MouseEventArgs e)
{
    if (e.Button == MouseButtons.Left)
    {
        // Release the mouse capture started by the mouse down.
        lblMoveForm.Capture = false; //select control
        // Create and send a WM_NCLBUTTONDOWN message.
        const int WM_NCLBUTTONDOWN = 0x00A1;
        const int HTCAPTION = 2;
        Message msg =
            Message.Create(this.Handle, WM_NCLBUTTONDOWN,
                new IntPtr(HTCAPTION), IntPtr.Zero);
        this.DefWndProc(ref msg);
    }
}

//For base form moving
private const int HT_CAPTION = 0x2;
private const int WM_NCHITTEST = 0x84;
private const int HT_CLIENT = 0x1;
protected override void WndProc(ref Message m)
{
    base.WndProc(ref m);
    if (m.Msg == WM_NCHITTEST)
        m.Result = (IntPtr)(HT_CAPTION);
}

//For any component you also want use to move form
private bool arrastando= false;
private Point pontoinicial= new Point(0,0);
private Point meu_offset;
//use this method for component event called MouseDown
private void dragMouseDown(object sender, MouseEventArgs e)
{
    arrastando = true;
    pontoinicial = new Point(e.X, e.Y);
}
//use this method for component event called MouseUp
private void dragMouseUp(object sender, MouseEventArgs e)
{
    arrastando=false;
}
//use this method for component event called MouseMove
private void dragMouseMove(object sender, MouseEventArgs e)
{
    if (arrastando)
    {
    Point p = PointToScreen(e.Location);
    ActiveForm.Location = new Point(p.X - this.pontoinicial.X,
                                    p.Y - this.pontoinicial.Y);
    }
}
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