Question

我想在某些HTML元素上使用拖动逻辑实现无边框窗口。我找到了一些有用的例子（比如frameless window for Chrome），这就是我尝试过的：

.title-area 
{
   -webkit-app-region: drag;
}

<div class='title-area'>
    A draggable area
</div>

然后，在C＃代码中，我实现了IDragHandler类：

internal class PromtDragHandler : IDragHandler
{
    bool IDragHandler.OnDragEnter(IWebBrowser browserControl, IBrowser browser, IDragData dragData, DragOperationsMask mask)
    {
        return false;
    }

    void IDragHandler.OnDraggableRegionsChanged(IWebBrowser browserControl, IBrowser browser, IList<DraggableRegion> regions)
    {

    }
}

方法OnDraggableRegionsChanged在开始时触发一次，OnDragEnter在我拖动元素“title-area”的某些文本时触发。但我不知道接下来要做什么让我的窗户移动？

更新。正如评论中所述，CefTestApp支持此拖动功能。在源代码中，我们有从DragHandler调用的方法OnSetDraggableRegions：

void RootWindowWin::OnSetDraggableRegions(
const std::vector<CefDraggableRegion>& regions) {
REQUIRE_MAIN_THREAD();

// Reset draggable region.
  ::SetRectRgn(draggable_region_, 0, 0, 0, 0);

  // Determine new draggable region.
  std::vector<CefDraggableRegion>::const_iterator it = regions.begin();
  for (;it != regions.end(); ++it) {
    HRGN region = ::CreateRectRgn(
        it->bounds.x, it->bounds.y,
        it->bounds.x + it->bounds.width,
        it->bounds.y + it->bounds.height);
    ::CombineRgn(
        draggable_region_, draggable_region_, region,
        it->draggable ? RGN_OR : RGN_DIFF);
    ::DeleteObject(region);
  }

  // Subclass child window procedures in order to do hit-testing.
  // This will be a no-op, if it is already subclassed.
  if (hwnd_) {
    WNDENUMPROC proc = !regions.empty() ?
        SubclassWindowsProc : UnSubclassWindowsProc;
    ::EnumChildWindows(
        hwnd_, proc, reinterpret_cast<LPARAM>(draggable_region_));
  }
}

我仍然不太了解，关于可拖动区域（在启动时仅触发一次）的确切信息如何帮助移动窗口？有人能解释我这个逻辑还是提供C＃等效的代码？

Answer 1

看看：https://github.com/qwqcode/CefSharpDraggableRegion

GIF

您可以在CSS中指定-webkit-app-region: drag来告诉CefSharp哪些区域是可拖动的（如操作系统的标准标题栏）。

Answer 2

<强> UPDATE2。我知道。这就是我在表单代码中添加的内容：

IntPtr DragableRegionNative = Native.CreateRectRgn(0, 0, 0, 0);

    void RegionsChangedCallback(DraggableRegion[] Regions)
    {

        Native.SetRectRgn(DragableRegionNative, 0, 0, 0, 0);

        if (Regions == null)
            return;

        foreach (var Region in Regions)
        {
            var RegionNative = Native.CreateRectRgn(
                Region.X, Region.Y,
                Region.X + Region.Width,
                Region.Y + Region.Height);

            Native.CombineRgn(DragableRegionNative, DragableRegionNative, RegionNative,
                Region.Draggable ? (int)Native.CombineRgnStyles.RGN_OR : (int)Native.CombineRgnStyles.RGN_DIFF);

            Native.DeleteObject(RegionNative);
        }
    }


    Point dragOffset = new Point();

    protected override void OnMouseDown(MouseEventArgs e)
    {
        base.OnMouseDown(e);

        if (e.Button == MouseButtons.Left)
        {
            dragOffset = this.PointToScreen(e.Location);
            dragOffset.X -= Location.X;
            dragOffset.Y -= Location.Y;
        }
    }

    protected override void OnMouseMove(MouseEventArgs e)
    {
        base.OnMouseMove(e);

        if (e.Button == MouseButtons.Left)
        {
            Point newLocation = this.PointToScreen(e.Location);

            newLocation.X -= dragOffset.X;
            newLocation.Y -= dragOffset.Y;

            Location = newLocation;
        }
    }

    void chromewb_IsBrowserInitializedChanged(object sender, IsBrowserInitializedChangedEventArgs e)
    {
        if (chromewb.IsBrowserInitialized)
        {
            ChromeWidgetMessageInterceptor.SetupLoop(chromewb, (m) =>
            {
                if (m.Msg == (int)Native.WM.WM_LBUTTONDOWN)
                {
                    var point = Native.ParsePoint(m.LParam.ToInt32());

                    if (Native.PtInRegion(DragableRegionNative, point.X, point.Y))
                        this.InvokeEx(() => Native.PostMessage(this.Handle, (uint)m.Msg, m.WParam, m.LParam));

                }
            });
        }
    }

如您所见，从Chrome浏览器拦截WM_LBUTTONDOWN事件就足够了，然后检查鼠标点是否属于标题区域，如果是，则将此消息发送到主窗体。一旦表单将获得WM_LBUTTONDOWN事件，内置表单方法OnMouseDown和OnMouseMove将执行其他工作。

CefSharp中的可拖动无边框窗口

2 个答案: