原因:父窗体中ToolStripMenuItem默认的快捷键和系统快捷键冲突
解决方式:注释父窗体中默认的Ctrl+C和Ctrl+V快捷键
xxxDesigner.cs
//this.copyToolStripMenuItem.ShortcutKeys = ((System.Windows.Forms.Keys)((System.Windows.Forms.Keys.Control | System.Windows.Forms.Keys.C))); //this.pasteToolStripMenuItem.ShortcutKeys = ((System.Windows.Forms.Keys)((System.Windows.Forms.Keys.Control | System.Windows.Forms.Keys.V)));