ContextMenuStrip.Owner属性null从嵌套ToolStripMenuItem检索时

Question

我有ContextMenuStrip两个ToolStripItems 的设置.第二个ToolStripItem有两个额外的嵌套ToolStripItems.我将其定义为:

ContextMenuStrip cms = new ContextMenuStrip();
ToolStripMenuItem contextJumpTo = new ToolStripMenuItem();
ToolStripMenuItem contextJumpToHeatmap = new ToolStripMenuItem();
ToolStripMenuItem contextJumpToHeatmapStart = new ToolStripMenuItem();
ToolStripMenuItem contextJumpToHeatmapLast = new ToolStripMenuItem();

cms.Items.AddRange(new ToolStripItem[] { contextJumpTo,
                                         contextJumpToHeatmap});
cms.Size = new System.Drawing.Size(176, 148);

contextJumpTo.Size = new System.Drawing.Size(175, 22);
contextJumpTo.Text = "Jump To (No Heatmapping)";

contextJumpToHeatmap.Size = new System.Drawing.Size(175, 22);
contextJumpToHeatmap.Text = "Jump To (With Heatmapping)";
contextJumpToHeatmap.DropDownItems.AddRange(new ToolStripItem[] { contextJumpToHeatmapStart, 
                                                                  contextJumpToHeatmapLast });

contextJumpToHeatmapStart.Size = new System.Drawing.Size(165, 22);
contextJumpToHeatmapStart.Text = "From Start of File";

contextJumpToHeatmapLast.Size = new System.Drawing.Size(165, 22);
contextJumpToHeatmapLast.Text = "From Last Data Point";

然后ToolStripMenuItem,我为我要响应的三个s 的点击事件设置了一个事件监听器.以下是方法(我只列出了三种方法中的两种):

void contextJumpTo_Click(object sender, EventArgs e)
{
    // Try to cast the sender to a ToolStripItem 
    ToolStripMenuItem menuItem = sender as ToolStripMenuItem;
    if (menuItem != null)
    {
        // Retrieve the ContextMenuStrip that owns this ToolStripItem 
        ContextMenuStrip owner = menuItem.Owner as ContextMenuStrip;
        if (owner != null)
        {
            // Get the control that is displaying this context menu 
            DataGridView dgv = owner.SourceControl as DataGridView;
            if (dgv != null)
                // DO WORK
        }
    } 
}

void contextJumpToHeatmapStart_Click(object sender, EventArgs e)
{
    // Try to cast the sender to a ToolStripItem 
    ToolStripMenuItem menuItem = sender as ToolStripMenuItem;
    if (menuItem != null)
    {
        // Retrieve the ToolStripItem that owns this ToolStripItem 
        ToolStripMenuItem ownerItem = menuItem.OwnerItem as ToolStripMenuItem;
        if (ownerItem != null)
        {
            // Retrieve the ContextMenuStrip that owns this ToolStripItem 
            ContextMenuStrip owner = ownerItem.Owner as ContextMenuStrip;
            if (owner != null)
            {
                // Get the control that is displaying this context menu 
                DataGridView dgv = owner.SourceControl as DataGridView;
                if (dgv != null)
                    // DO WORK
            }
        }
    }
}

这是我的问题:

我的contextJumpTo_Click方法非常好.我们一直到我确定DataGridView点击来自哪里,我可以继续.该contextJumpTo ToolStripMenuItem然而,没有一个嵌套的菜单上的项目ContextMenuStrip.

但我的方法contextJumpToHeatmapStart_Click不正常.当我到达我确定的行时owner.SourceControl,SourceControl为空,我无法继续.现在我知道这ToolStripMenuItem是嵌套在我的另一个ContextMenuStrip,但为什么SourceControl属性突然出现在我身上ContextMenuStrip呢？

如何获得SourceControl嵌套ToolStripMenuItem的ContextMenuStrip？

Answer 1

我相信这是一个错误.

我试图抓取工具条父项列表以获取ContextStripMenu所有者,该工作正常,但SourceControl属性始终为null.

看起来常见的工作是在上下文菜单的开头设置控件:

private Control menuSource;

cms.Opening += cms_Opening;

void cms_Opening(object sender, CancelEventArgs e) {
  menuSource = ((ContextMenuStrip)sender).SourceControl;
}

然后你的代码基本上变成了这个:

DataGridView dgv = menuSource as DataGridView;
if (dgv != null) {
  // do work
}