C displays and hides the taskbar corresponding to the window

WPF Full screen window in , Will automatically hide the taskbar .

How to hide the taskbar in a non full screen window ？ Is there even a scene , After hiding the taskbar, customize a set of system taskbar to display ？

Some concepts will be described in stages below , The task bar 、 Search window 、 Control window display .

1. Main screen taskbar

The task bar , In fact, it is also a window , The name of the taskbar on the main screen is "Shell_TrayWnd".

So you can find the window by name , Then display the window 、 Hide operations .

The following is the control operation of the main screen taskbar ：

public static class ScreenTaskBar
 {
private const int SwHide = 0; // Hidden window 
private const int SwRestore = 9;// Restore  window 

[DllImport("user32.dll")]
private static extern int ShowWindow(int hwnd, int nCmdShow);
[DllImport("user32.dll")]
private static extern int FindWindow(string lpClassName, string lpWindowName);
/// <summary>
/// Show taskbar
/// </summary>
public static void Show()
 {
ShowWindow(FindWindow("Shell_TrayWnd", null), SwRestore);
 }
/// <summary>
/// Hide taskbar
/// </summary>
public static void Hide()
 {
ShowWindow(FindWindow("Shell_TrayWnd", null), SwHide);
 }
}

2. Multi screen taskbar

If it's multi screen , The scenario of processing the taskbar , Generally, it is used to operate the taskbar corresponding to the window .

How to get the taskbar where any window is located ？ Since the taskbar is also a window , So our focus is how to find the taskbar window .

User32 Yes EnumWindows function , You can traverse all windows of the current computer .

private delegate bool EnumWindowProc(IntPtr hWnd, int lParam);
[DllImport("user32")]
private static extern bool EnumWindows(EnumWindowProc lpEnumFunc, int lParam);

EnumWindowProc Defines the handling of delegates . Add callback method , The parameters returned are handle information ：

bool OnEnumWindow(IntPtr hWnd, int lparam)
 {
// Add code XXX
return true;
}

You can then add code inside the callback , According to the handle information of the window , Let's get some information from the window , Class name 、 Window title 、 Window Bounds（ Location 、 size ）

[DllImport("user32")]
private static extern int GetClassName(IntPtr hWnd, StringBuilder lpString, int nMaxCount);
[DllImport("user32")]
private static extern int GetWindowText(IntPtr hWnd, StringBuilder lptrString, int nMaxCount);
[DllImport("user32")]
private static extern bool GetWindowRect(IntPtr hWnd, ref LPRECT rect);

The following is some of the window class information traversed ：

therefore , You can filter out those to TrayWnd At the end of a string , These are taskbar windows .

After that is how to filter out the taskbar we want , That is, the taskbar corresponding to the window .

Windows and taskbar , Are linked together through the screen . Get the current screen information through the window , Taskbar Bounds If with the screen Bounds The intersection , This means that the taskbar is on this screen .

var intPtr = new WindowInteropHelper(window).Handle;// Get the handle of the current window 
var screen = Screen.FromHandle(intPtr);// Get the current screen 
var currentScreenBounds = screen.Bounds;
var taskBars = windows.Where(i => i.ClassName.Contains("TrayWnd"));
var currentTaskBar = taskBars.FirstOrDefault(i => i.Bounds.IntersectsWith(currentScreenBounds));

Get taskbar , You can also get the screen through the handle of the taskbar , Determine whether it is the same as the screen where the main window is located .

After obtaining the specified taskbar information , We can control the taskbar display 、 Hide the . Call next user32 Lower function ShowWindow that will do ：

private const int SwHide = 0; // Hidden window 
private const int SwRestore = 9;// Restore window 
/// <summary>
/// Through handle , Form display function
/// </summary>
/// <param name="hWnd"> Form handle </param>
/// <param name="cmdShow"> Display mode </param>
/// <returns> Return success or not </returns>
[DllImport("user32.dll", EntryPoint = "ShowWindowAsync", SetLastError = true)]
public static extern bool ShowWindow(IntPtr hWnd, int cmdShow);

  there ShowWindow, Same as that called by the default taskbar operation above ShowWindow Dissimilarity , The handle parameter is IntPtr