仿word导航窗口的展开与折叠

// 标识是否是展开状态
bool isExtend = true;
// 定义可以扩展的宽度
const int PanelWidth = 444;
private void expandableSplitter1_Click(object sender, EventArgs e)
{
if (isExtend)
{
this.Width -= 444;
isExtend = false;
}
else
{
this.Width += 444;
isExtend = true;
}
}