如何使用 Windows 窗体在窗口标题栏中绘制自定义按钮？

Question

如何在窗体标题栏中的最小化、最大化和关闭按钮旁边绘制自定义按钮？

我知道您需要使用 Win32 API 调用并覆盖 WndProc 过程，但我一直无法找到正确的解决方案。

有谁知道如何做到这一点？ 更具体地说，有谁知道在 Vista 中可行的方法吗？

Answer 1

以下内容将在 XP 中运行，我没有方便的 Vista 机器来测试它，但我认为你的问题是由于某种不正确的 hWnd 引起的。 无论如何，继续处理注释很差的代码。

// The state of our little button
ButtonState _buttState = ButtonState.Normal;
Rectangle _buttPosition = new Rectangle();

[DllImport("user32.dll")]
private static extern IntPtr GetWindowDC(IntPtr hWnd);
[DllImport("user32.dll")]
private static extern int GetWindowRect(IntPtr hWnd, 
                                        ref Rectangle lpRect);
[DllImport("user32.dll")]
private static extern int ReleaseDC(IntPtr hWnd, IntPtr hDC);
protected override void WndProc(ref Message m)
{
    int x, y;
    Rectangle windowRect = new Rectangle();
    GetWindowRect(m.HWnd, ref windowRect);

    switch (m.Msg)
    {
        // WM_NCPAINT
        case 0x85:
        // WM_PAINT
        case 0x0A:
            base.WndProc(ref m);

            DrawButton(m.HWnd);

            m.Result = IntPtr.Zero;

            break;

        // WM_ACTIVATE
        case 0x86:
            base.WndProc(ref m);
            DrawButton(m.HWnd);

            break;

        // WM_NCMOUSEMOVE
        case 0xA0:
            // Extract the least significant 16 bits
            x = ((int)m.LParam << 16) >> 16;
            // Extract the most significant 16 bits
            y = (int)m.LParam >> 16;

            x -= windowRect.Left;
            y -= windowRect.Top;

            base.WndProc(ref m);

            if (!_buttPosition.Contains(new Point(x, y)) && 
                _buttState == ButtonState.Pushed)
            {
                _buttState = ButtonState.Normal;
                DrawButton(m.HWnd);
            }

            break;

        // WM_NCLBUTTONDOWN
        case 0xA1:
            // Extract the least significant 16 bits
            x = ((int)m.LParam << 16) >> 16;
            // Extract the most significant 16 bits
            y = (int)m.LParam >> 16;

            x -= windowRect.Left;
            y -= windowRect.Top;

            if (_buttPosition.Contains(new Point(x, y)))
            {
                _buttState = ButtonState.Pushed;
                DrawButton(m.HWnd);
            }
            else
                base.WndProc(ref m);

            break;

        // WM_NCLBUTTONUP
        case 0xA2:
            // Extract the least significant 16 bits
            x = ((int)m.LParam << 16) >> 16;
            // Extract the most significant 16 bits
            y = (int)m.LParam >> 16;

            x -= windowRect.Left;
            y -= windowRect.Top;

            if (_buttPosition.Contains(new Point(x, y)) &&
                _buttState == ButtonState.Pushed)
            {
                _buttState = ButtonState.Normal;
                // [[TODO]]: Fire a click event for your button 
                //           however you want to do it.
                DrawButton(m.HWnd);
            }
            else
                base.WndProc(ref m);

            break;

        // WM_NCHITTEST
        case 0x84:
            // Extract the least significant 16 bits
            x = ((int)m.LParam << 16) >> 16;
            // Extract the most significant 16 bits
            y = (int)m.LParam >> 16;

            x -= windowRect.Left;
            y -= windowRect.Top;

            if (_buttPosition.Contains(new Point(x, y)))
                m.Result = (IntPtr)18; // HTBORDER
            else
                base.WndProc(ref m);

            break;

        default:
            base.WndProc(ref m);
            break;
    }
}

private void DrawButton(IntPtr hwnd)
{
    IntPtr hDC = GetWindowDC(hwnd);
    int x, y;

    using (Graphics g = Graphics.FromHdc(hDC))
    {
        // Work out size and positioning
        int CaptionHeight = Bounds.Height - ClientRectangle.Height;
        Size ButtonSize = SystemInformation.CaptionButtonSize;
        x = Bounds.Width - 4 * ButtonSize.Width;
        y = (CaptionHeight - ButtonSize.Height) / 2;
        _buttPosition.Location = new Point(x, y);

        // Work out color
        Brush color;
        if (_buttState == ButtonState.Pushed)
            color = Brushes.LightGreen;
        else
            color = Brushes.Red;

        // Draw our "button"
        g.FillRectangle(color, x, y, ButtonSize.Width, ButtonSize.Height);
    }

    ReleaseDC(hwnd, hDC);
}

private void Form1_Load(object sender, EventArgs e)
{
    _buttPosition.Size = SystemInformation.CaptionButtonSize;
}

Answer 2

我知道距离上次回答已经很久了，但这最近确实对我有帮助，我喜欢用我的评论和修改来更新克里斯提供的代码。
该版本在 Win XP 和 Win 2003 上完美运行。在 Win 2008 上，调整窗口大小时有一个我无法识别的小错误。 也适用于 Vista（无 Aero），但请注意，标题栏按钮不是方形的，按钮尺寸应考虑到这一点。

 switch (m.Msg)
            {
                // WM_NCPAINT / WM_PAINT        
                case 0x85:
                case 0x0A:
                    //Call base method
                    base.WndProc(ref m);
                    //we have 3 buttons in the corner of the window. So first's new button left coord is offseted by 4 widths
                    int crt = 4;
                    //navigate trough all titlebar buttons on the form
                    foreach (TitleBarImageButton crtBtn in titleBarButtons.Values)
                    {
                        //Calculate button coordinates
                        p.X = (Bounds.Width - crt * crtBtn.Size.Width);
                        p.Y = (Bounds.Height - ClientRectangle.Height - crtBtn.Size.Height) / 2;
                        //Initialize button and draw
                        crtBtn.Location = p;
                        crtBtn.ButtonState = ImageButtonState.NORMAL;
                        crtBtn.DrawButton(m.HWnd);
                        //increment button left coord location offset
                        crt++;
                    }
                    m.Result = IntPtr.Zero;
                    break;
                // WM_ACTIVATE      
                case 0x86:
                    //Call base method
                    base.WndProc(ref m);
                    //Draw each button
                    foreach (TitleBarImageButton crtBtn in titleBarButtons.Values)
                    {
                        crtBtn.ButtonState = ImageButtonState.NORMAL;
                        crtBtn.DrawButton(m.HWnd);
                    }
                    break;
                // WM_NCMOUSEMOVE        
                case 0xA0:
                    //Get current mouse position
                    p.X = ((int)m.LParam << 16) >> 16;// Extract the least significant 16 bits            
                    p.Y = (int)m.LParam >> 16;        // Extract the most significant 16 bits          
                    p.X -= windowRect.Left;
                    p.Y -= windowRect.Top;

                    //Call base method
                    base.WndProc(ref m);

                    ImageButtonState newButtonState;
                    foreach (TitleBarImageButton crtBtn in titleBarButtons.Values)
                    {
                        if (crtBtn.HitTest(p))
                        {//mouse is over the current button
                            if (crtBtn.MouseButtonState == MouseButtonState.PRESSED)
                                //button is pressed - set pressed state
                                newButtonState = ImageButtonState.PRESSED;
                            else
                                //button not pressed - set hoover state
                                newButtonState = ImageButtonState.HOOVER;
                        }
                        else
                        {
                            //mouse not over the current button - set normal state
                            newButtonState = ImageButtonState.NORMAL;
                        }

                        //if button state not modified, do not repaint it.
                        if (newButtonState != crtBtn.ButtonState)
                        {
                            crtBtn.ButtonState = newButtonState;
                            crtBtn.DrawButton(m.HWnd);
                        }
                    }
                    break;
                // WM_NCLBUTTONDOWN     
                case 0xA1:
                    //Get current mouse position
                    p.X = ((int)m.LParam << 16) >> 16;// Extract the least significant 16 bits
                    p.Y = (int)m.LParam >> 16;        // Extract the most significant 16 bits      
                    p.X -= windowRect.Left;
                    p.Y -= windowRect.Top;

                    //Call base method
                    base.WndProc(ref m);

                    foreach (TitleBarImageButton crtBtn in titleBarButtons.Values)
                    {
                        if (crtBtn.HitTest(p))
                        {
                            crtBtn.MouseButtonState = MouseButtonState.PRESSED;
                            crtBtn.ButtonState = ImageButtonState.PRESSED;
                            crtBtn.DrawButton(m.HWnd);
                        }
                    }
                    break;
                // WM_NCLBUTTONUP   
                case 0xA2:
                case 0x202:
                    //Get current mouse position
                    p.X = ((int)m.LParam << 16) >> 16;// Extract the least significant 16 bits   
                    p.Y = (int)m.LParam >> 16;        // Extract the most significant 16 bits 
                    p.X -= windowRect.Left;
                    p.Y -= windowRect.Top;

                    //Call base method
                    base.WndProc(ref m);
                    foreach (TitleBarImageButton crtBtn in titleBarButtons.Values)
                    {
                        //if button is press
                        if (crtBtn.ButtonState == ImageButtonState.PRESSED)
                        {
                            //Rasie button's click event
                            crtBtn.OnClick(EventArgs.Empty);

                            if (crtBtn.HitTest(p))
                                crtBtn.ButtonState = ImageButtonState.HOOVER;
                            else
                                crtBtn.ButtonState = ImageButtonState.NORMAL;
                        }

                        crtBtn.MouseButtonState = MouseButtonState.NOTPESSED;
                        crtBtn.DrawButton(m.HWnd);
                    }
                    break;
                // WM_NCHITTEST    
                case 0x84:
                    //Get current mouse position
                    p.X = ((int)m.LParam << 16) >> 16;// Extract the least significant 16 bits
                    p.Y = (int)m.LParam >> 16;        // Extract the most significant 16 bits
                    p.X -= windowRect.Left;
                    p.Y -= windowRect.Top;

                    bool isAnyButtonHit = false;
                    foreach (TitleBarImageButton crtBtn in titleBarButtons.Values)
                    {
                        //if mouse is over the button, or mouse is pressed 
                        //(do not process messages when mouse was pressed on a button)
                        if (crtBtn.HitTest(p) || crtBtn.MouseButtonState == MouseButtonState.PRESSED)
                        {
                            //return 18 (do not process further)
                            m.Result = (IntPtr)18;
                            //we have a hit
                            isAnyButtonHit = true;
                            //return 
                            break;
                        }
                        else
                        {//mouse is not pressed and not over the button, redraw button if needed  
                            if (crtBtn.ButtonState != ImageButtonState.NORMAL)
                            {
                                crtBtn.ButtonState = ImageButtonState.NORMAL;
                                crtBtn.DrawButton(m.HWnd);
                            }
                        }
                    }
                    //if we have a hit, do not process further
                    if (!isAnyButtonHit)
                        //Call base method
                        base.WndProc(ref m);
                    break;
                default:
                    //Call base method
                    base.WndProc(ref m);
                    //Console.WriteLine(m.Msg + "(0x" + m.Msg.ToString("x") + ")");
                    break;
            }

该代码演示了需要处理的消息以及如何处理它们。
该代码使用自定义 TitleBarButton 对象的集合。 该类太大，无法包含在此处，但如果需要，我可以提供它以及示例。

Answer 3

绘图似乎是简单的部分，以下内容将做到这一点：

[编辑：代码已删除，请参阅我的其他答案]

真正的问题是更改状态并检测按钮上的点击...为此，您需要挂钩作为程序的全局消息处理程序，.NET 似乎隐藏了不在实际容器区域中的表单的鼠标事件（即鼠标移动并单击标题栏）。 我正在寻找相关信息，现在找到了，我正在研究它，应该不会太难......如果我们能弄清楚这些消息实际上传递的是什么。