Winform :判断是否为顶层窗口

今天遇到一个需求，就像MSN提示信息一样，如果窗口未当前，则需闪烁提醒用户

好久没动笔了，写一写记下来吧，嘿嘿

引用：http://www.codeproject.com/KB/dialog/Is_My_Application_on_Top_.aspx

以上图是从copeproject copy下来的，从此图可以看出一个流程吧，但是作者用的是一个GetTopWindow的函数，感觉并不正确，尽管做出来的效果是跟讲的一样，但是。。。。有兴趣的朋友可以看一下，以下是他判断是否当前窗口为最顶层的函数，VB。NET代码

 

Private Function IsOnTop(ByVal hwnd As Integer) As Boolean      

    Dim i As Integer = GetTopWindow(0)    'Initialize      

    Dim x As Integer = 1      

    Dim s As String      

       

    ' Enumeration      

    Do          

        i = GetNextWindow(i, 2) ' Find next window in Z-order      

        If i = hwnd Then      

            Exit Do      

        Else      

            If i = 0 Then        ' Never find any window match the input handle      

                Return False      

            End If      

        End If      

       

        If IsWindowVisible(i) = True Then      

            s = Space(256)      

            If GetWindowText(i, s, 255) <> 0 Then      

            ' Very important to prevent confusing      

            ' of BalloonTips and ContextMenuStrips      

                x += 1      

            End If      

        End If      

    Loop      

       

    ' x is Z-order number      

       

    If x = 1 Then      

        Return True      

    Else      

        Return False      

    End If      

End Function      

 

但通过console打印出自已当前处于最顶层窗口句柄时，也打印出GetTopWindow获得的句柄，再用SPY++查看，并不一致，那里出错呢，对这函数的理解出错了么？

 

幸好忽闪过一个函数：

[DllImport("user32.dll")]

  private static extern IntPtr GetForegroundWindow();

再与当前自已处于顶层的窗口句柄比较了一下，是一致的，就直接采用了

 

 

查了一下MSDN

GetForegroundWindow Function

The GetForegroundWindow function returns a handle to the foreground window (the window with which the user is currently working). The system assigns a slightly higher priority to the thread that creates the foreground window than it does to other threads.

 

GetTopWindow Function

The GetTopWindow function examines the Z order of the child windows associated with the specified parent window and retrieves a handle to the child window at the top of the Z order.

自已英语很菜，但这gettopwindow的意思是获取子窗口的顶层窗口的句柄,但网上别人说：传0进去是获得WINDOWS当前顶层窗口？

 

而闪烁则是通过flashwindow函数，这大多C++ coder都清楚的，嘿嘿，就能跟MSN一样，当用户并未操作当前消息窗口时能提示

 

顺便写写这个例中过程中曾用过的几个API

[DllImport("user32", EntryPoint = "GetTopWindow", CharSet = CharSet.Ansi, SetLastError = true, ExactSpelling = true)]

public static extern int GetTopWindow(int hwnd);

[DllImport("user32", EntryPoint = "GetWindow", CharSet = CharSet.Ansi, SetLastError = true, ExactSpelling = true)]

public static extern int GetNextWindow(int hwnd, int wFlag);

[DllImport("user32", EntryPoint = "IsWindowVisible", CharSet = CharSet.Ansi, SetLastError = true, ExactSpelling = true)]

public static extern bool IsWindowVisible(int hwnd);

[DllImport("user32", EntryPoint = "GetWindowTextA", CharSet = CharSet.Ansi, SetLastError = true, ExactSpelling = true)]

public static extern int GetWindowText(int hwnd, string lpString, int cch);

[DllImport("user32.dll")]

private static extern IntPtr GetForegroundWindow();

 

 

也记一下一篇文章，很好的介结了WINDOWS窗口机制，改天好好验证一下每个函数

http://blog.csdn.net/chenshaoying/archive/2008/04/24/2324304.aspx

 

其实上面主要涉及到的，还是一个Z轴的问题，老的WIN32 coder是很熟啦，通过Z轴，能做出一些很漂亮的效果哦，最明显的就是一个OUTLOOK的控件，codeproject上有好几个介绍的，一个是作者自已写的，好长好长的代码呀，另一个，则是作者通过设置Z轴达到的效果，很好很强大

 

 

以下是其设置Z轴的一段代码

         void ButtonClick(object sender, System.EventArgs e)

         {

              // Get the clicked button...

              Button clickedButton = (Button)sender;   

              // ... and it's tabindex

              int clickedButtonTabIndex = clickedButton.TabIndex;    

             

              // Send each button to top or bottom as appropriate

              foreach (Control ctl in panel1.Controls)

              {

                   if (ctl is Button)

                   {

                       Button btn = (Button)ctl;

                       if (btn.TabIndex > clickedButtonTabIndex)

                       {

                            if (btn.Dock != DockStyle.Bottom)

                            {

                                 btn.Dock = DockStyle.Bottom;

                                 // This is vital to preserve the correct order

                                 btn.BringToFront();             

                                                   }

                       }

                       else

                       {

                            if (btn.Dock != DockStyle.Top)

                            {

                                 btn.Dock = DockStyle.Top;

                                 // This is vital to preserve the correct order

                                 btn.BringToFront();

                                                   }

                       }

                   }

              }

             

              // Determine which button was clicked.

              switch (clickedButton.Text)

              {

                   case "Cars":

                       CreateCarList();

                       break;

                      

                   case "Outlook Shortcuts":

                       CreateOutlookList();

                       break;

                      

                   case "Zip Files":

                       CreateZipList();

                       break;

              }

                     listView1.BringToFront(); // Without this, the buttons will hide the items.

             

         }

 

很简单地设置一个Z轴就达到OUTLook效果了，给自已标志一下，加油

 

别告诉我那种VS效果是怎么做出来的哦，那要说的话可以写好长好长的一篇文章了，CODEPROJECT上就有一个开源的控件做，嘿嘿，很佩服作者的精神，坚持下去。。。。。。。。。

 

转载于:https://www.cnblogs.com/yellowyu/archive/2008/09/03/1282990.html