/// <summary>
/// 菜单：撤销
/// </summary>
private void 撤销ToolStripMenuItem_Click(object sender, EventArgs e)
{
this.menuStrip1.Items.Find("撤销ToolStripMenuItem", true)[0].Enabled = core.MenuUndo();
this.menuStrip1.Items.Find("重做ToolStripMenuItem", true)[0].Enabled = core.IsAbleRedo();
this.core.RefreshCodeContext();
}