上下文菜单被切断在WPF某些情况下， [英] Context menu is cut in some situations in WPF

问题描述

右键菜单被截断在不同的.NET框架。看到里面的ZIP文件的图像（有两个屏幕，一个来自XP等也从Win7）。

Context menu is truncated in different .NET Framework. See images inside ZIP file (there are two screenshots, one from XP and other from Win7).

我创建了一个简单的Visual Studio 2010的解决方案，瑞普我的问题。

I created a simple Visual Studio 2010 solution which repro my issue.

（ http://www.mediafire.com/download.php?doq7gsh75qgvzwq ）。

在XP似乎做工精细，但Windows 7。

On XP it seems to work fine, but not on Windows 7.

这个问题可以复制在Windows 7中，如果目标的.NET Framework 3.5（包括SP1）（请参阅从压缩图像）。

The issue can be reproduced on Windows 7 if target .NET Framework is 3.5 (including SP1) (please see the image from zip).

如果我更改目标框架4.0，它工作正常还对Windows 7操作系统。

If I change the target framework to 4.0 it works fine also on Windows 7.

时的一个解决方案，使上下文菜单完全可见的.NET Framework 3.5的Windows 7操作系统吗？

Is a solution to make context menu full visible in .NET Framework 3.5 on Windows 7 OS ?

推荐答案

看来，文本菜单加载时的 ScrollContent presenter 的菜单是不正确的尺寸，裁剪项目presenter 的菜单项 S（下面是可视化树显示问题的删节版）。

It seems that when the ContextMenu is loaded the ScrollContentPresenter for the menu isn't sized correctly, clipping the ItemPresenter of the MenuItems (Below is an abridged version of the visual tree showing the issue).

PopupRoot, Acutal Width: 219,027, Desired Width: 219,027
    Decorator, Acutal Width: 219,027, Desired Width: 219,027
        NonLogicalAdornerDecorator, Acutal Width: 219,027, Desired Width: 219,027
            ContextMenuProxy, Acutal Width: 219,027, Desired Width: 219,027
                SystemDropShadowChrome, Acutal Width: 214,027, Desired Width: 219,027
                    Border, Acutal Width: 214,027, Desired Width: 214,027
                        Grid, Acutal Width: 212,027, Desired Width: 212,027
                            Rectangle, Acutal Width: 28,000, Desired Width: 32,000
                            Rectangle, Acutal Width: 1,000, Desired Width: 31,000
                            Rectangle, Acutal Width: 1,000, Desired Width: 32,000
                            ScrollViewer, Acutal Width: 210,027, Desired Width: 212,027
                                Grid, Acutal Width: 210,027, Desired Width: 210,027
                                    Border, Acutal Width: 210,027, Desired Width: 210,027
                                        ScrollContentPresenter, Acutal Width: 210,027, Desired Width: 210,027
                                            ItemsPresenter, Acutal Width: 241,047, Desired Width: 245,047

无效化的的文本菜单的视觉根的措施（即 PopupRoot ）菜单时加载应引起布局进行更新以显示为产品presenter正确的边界。

Invalidating the measure of the of the ContextMenu's visual root (the PopupRoot) when the menu is loaded should cause the layout to be updated to display the correct bounds for the ItemsPresenter.

的处理程序菜单中的Load事件：

The handler for the menu's Load event:

private void mainMenu_Loaded(object sender, RoutedEventArgs e)
{
    if (sender != null)
    {
        ContextMenu menu = sender as ContextMenu;
        if (menu != null)
        {
           // get the visual root for the context menu
           var root = (FrameworkElement)GetVisualTreeRoot(menu);

           // invalidate the menu's layout
           root.InvalidateMeasure();
        }             
    }
}

GetVisu​​alTreeRoot方式：

GetVisualTreeRoot method:

private DependencyObject GetVisualTreeRoot(DependencyObject control)
{
    DependencyObject parent = VisualTreeHelper.GetParent(control);
    if (parent != null)
    {
        return GetVisualTreeRoot(parent);
    }
    else
    {
        return control;
    }
}

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