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這是我在構造函數中我做:僅當listView不爲空時,我如何才能激活/啓用contextmenustrip菜單?
ListViewCostumControl.lvnf.ContextMenuStrip = contextMenuStrip1;
ToolStripMenuItem item1 = new ToolStripMenuItem();
item1.Name = "Open File Folder Location";
item1.Text = "Open File Folder Location";
item1.Click += contextMenuStrip1_ItemClick;
ToolStripMenuItem item2 = new ToolStripMenuItem();
item2.Name = "Launch File";
item2.Text = "Launch File";
item2.Click += contextMenuStrip2_ItemClick;
ToolStripMenuItem item3 = new ToolStripMenuItem();
item3.Name = "Copy File";
item3.Text = "Copy File";
item3.Click += contextMenuStrip3_ItemClick;
contextMenuStrip1.Items.Add(item1);
contextMenuStrip1.Items.Add(item2);
contextMenuStrip1.Items.Add(item3);
但即使ListView控件lvnf是空的,它會顯示在右鍵菜單。 我希望只有當ListViewCostumControl.lvnf.Items.Count大於0時才能啓用菜單。
而且由於在程序中,listView可能會變得空白,不僅在運行程序時,我還需要在程序運行時檢查它,而不僅僅是一次啓動。