窗体显示

Question

问个菜菜问题，在父窗体点击按钮显示子窗体，用Show()（不是ShowDialog())怎么控制按钮使子窗体不重复显示。

Answer 1

单件模式
  public partial class Form1 : Form
    {
        private void button1_Click(object sender, EventArgs e)
        {
            Form2.ShowChildForm();
        }
    } public partial class Form2 : Form
    {
        private static Form2 formInstance;        public static Form2 Instance 
        {
            get 
            {
                if(formInstance == null)
                {
                    formInstance = new Form2();
                }
                return formInstance;
            }
          
        }        public static void ShowChildForm()
        {
            if(!Instance.Visible)
            {
                Instance.Show();
            }
        }
    }

Answer 2

在当前窗体设置一个子窗体的字段为 subForm（子窗体类为SubForm）
button1_Click(..)
{
   if(subForm == null)
   {
      SubForm subForm = new SubForm();
      subForm.Show();
   }
}

Answer 3

加
else
{
   subForm.Show();
}

Answer 4

先定义类：
public class SingleForm
    {
        private static YourForm _YourForm;
        public static YourForm GetYourForm
        {    
          set{ _YourForm=value;}
          get{ return _YourForm;}   
  }
}而后在事件中添加下面代码：if(SingleForm.GetYourForm==null) // 第一次初始化
            {
                YourForm frm=new YourForm();
                SingleForm.GetYourForm=frm;
                frm.MdiParent=this;  
                frm.Show();
            else
            {
                SingleForm.GetYourForm.Activate();
            }

Answer 5

非MDI窗体打开不重复:private void btn_Click(object sender, EventArgs e)
{
        if (Fuseredit == null || Fuseredit.IsDisposed)//如果该窗体为空或者被释放了
        {
                Fuseredit = new FUserEdit(this);//新建该窗体
                Fuseredit.Show();//SHOW
                BoundForm(Fuseredit);//绑定窗口弹出位置
        }
        else
        {
                Fuseredit.Focus();//否则该窗体获得焦点
        }
}
private void BoundForm(Form f)//绑定窗体
{
     int i = int.Parse (Application.OpenForms.Count.ToString()); 
     Rectangle rect = new Rectangle(this.Width, 30*i, f.Width, f.Height);
     f.Bounds = rect;
}MDI子窗体不重复
http://blog.csdn.net/tjvictor/archive/2007/01/18/1486420.aspx
http://www.chinancre.com.cn/two/C/fudao/200811/5400.html