private void toolStripButton1_Click(object sender, EventArgs e)
{
//利用MdiChildren遍历所有子窗体，并依次关闭
Form[] CFrmList = this.MdiChildren;
foreach (Form CFrm in CFrmList)
{
CFrm.Close();
}
}
private void toolStripButton1_Click(object sender, EventArgs e)
{
//利用MdiChildren遍历所有子窗体，并依次关闭
Form[] CFrmList = this.MdiChildren;
//在这里我们定义了一个Form类型的数组CFrmList
foreach (Form CFrm in CFrmList)
{
CFrm.Close();
}
//此时窗体不太美观，我们对父窗体进行还原操作
this.label1.Visible = true; //还原父窗体上的标题文字；
this.pictureBox1.Visible = true; //还原父窗体上的标题文字
this.label2.Visible = true; //还原父窗体上的版权文本
}