ContextMenuStrip.Owner属性null从嵌套ToolStripMenuItem检索时

我有一个带有两个ToolStripItem的ContextMenuStrip设置。 第二个ToolStripItem有两个额外的嵌套ToolStripItem 。 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，我为我想要响应的三个ToolStripMenuItem的click事件设置一个事件监听器。 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方法工作得很好。 我们一直到我确定点击来自哪个DataGridView的地方，我可以继续。 但是， contextJumpTo ToolStripMenuItem不是ContextMenuStrip上的嵌套菜单项。

但我对contextJumpToHeatmapStart_Click方法不能正常工作。 当我到达我确定owner.SourceControl ， SourceControl为null，我无法继续。 现在我知道这个ToolStripMenuItem嵌套在我的ContextMenuStrip另一个下，但是为什么我的ContextMenuStrip上的SourceControl属性突然为null？

如何获取ContextMenuStrip的嵌套ToolStripMenuItem的SourceControl ？

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 }