C# (CSharp) MDI sub_Form示例

示例#1

 private void openSubFormToolStripMenuItem_Click(object sender, EventArgs e)
 {
     if (a == null)
     {
         a             = new sub_Form();
         a.FormClosed += new FormClosedEventHandler(sub_Form_FormClosed);
         a.MdiParent   = this;
         a.Show();
     }
 }

示例#2

 private void sub_Form_FormClosed(object sender, FormClosedEventArgs e)
 {
     a = null;
 }