正在阅读：MDI应用中的单实例(singleton)窗口MDI应用中的单实例(singleton)窗口

2004-06-25 09:53 出处：CSDN 作者：turnmissile [翻译] 责任编辑：linjixiong

下面的代码片断假设你的多文档应用程序中包含一个toolbar。当你点击toolBarButton1 按钮时，将会创建并显示一个 Patients 子窗口。下面的代码在单机事件时发生。

private void toolBar1_ButtonClick(object sender,
     System.Windows.Forms.ToolBarButtonClickEventArgs e)
{
    // a flag to store if the child form is opened or not
    bool found = false;

    if (e.Button == toolBarButton1)
    {
       // get all of the MDI children in an array
       Form[] charr = this.MdiChildren;

       if (charr.Length == 0)      // no child form is opened
       {
          Patients myPatients = new Patients();
          myPatients.MdiParent = this;
          // The StartPosition property is essential
          // for the location property to work
          myPatients.StartPosition = FormStartPosition.Manual;
          myPatients.Location = new Point(0,0);
          myPatients.Show();
        }
        else      // child forms are opened
        {