软工项目查许久资料才搞定，stackoverflow上的资料一直没说清楚花了不少时间 = =

借此水一篇博文，不过好像还需要实现一个让窗口不贴在桌面上的需求，但是这个把父窗口设置成Zero应该就行了

实现步骤

WPF中的应用场景：将窗口钉在桌面上，使用快捷键Win+D显示桌面时不会让窗口隐藏

在窗口类中引入dll，调用系统api用于查找句柄、设置句柄等操作

// 获取指定窗口的样式
[DllImport("user32.dll", SetLastError = true)]
static extern UInt64 GetWindowLong(IntPtr hWnd, int nIndex);
// 设置指定窗口的样式
[DllImport("user32.dll")]
static extern int SetWindowLong(IntPtr hWnd, int nIndex, UInt64 dwNewLong);
// 获取桌面Desktop窗口的Handle
[DllImport("user32.dll")]
static extern IntPtr GetDesktopWindow();
// 设置窗口的父窗口
[DllImport("user32.dll")]
static extern IntPtr SetParent(IntPtr hWndChild, IntPtr hWndNewParent);
// 查找窗口handle
[DllImport("user32.dll", SetLastError = true)]
static extern IntPtr FindWindow(string lpWindowClass, string lpWindowName);
// 查找窗口handle
[DllImport("user32.dll", SetLastError = true)]
static extern IntPtr FindWindowEx(IntPtr parentHandle, IntPtr childAfter, string className, string windowTitle);

然后通过窗口的特性来查找正确的桌面窗口

桌面窗口的类名为WorkerW，但是根据这个类名会有重名的窗口，所以需要另外编写函数来进行查找

可以通过Microsoft Spy++来查看，正确的桌面窗口下至少有一个子窗口，其类名为SHELLDLL_DefView

查找正确桌面窗口句柄的函数：

public static IntPtr SearchDesktopHandle() {
    IntPtr hRoot = GetDesktopWindow();
    IntPtr hShellDll = IntPtr.Zero;
    IntPtr hDesktop = FindWindowEx(hRoot, IntPtr.Zero, "WorkerW", String.Empty);
    while (true) {
        hShellDll = FindWindowEx(hDesktop, IntPtr.Zero, "SHELLDLL_DefView", String.Empty);
        if (hShellDll != IntPtr.Zero) {
            return hDesktop;
        }
        hDesktop = FindWindowEx(hRoot, hDesktop, "WorkerW", String.Empty);
    }

    return IntPtr.Zero;
}

然后还需要把窗口添加一个WS_CHILD的属性，否则调用SetParent函数是没有任何用处的(注意：具有WS_POPUP 属性的窗口需要将其去掉，否则存在冲突)

const int GWL_STYLE = (-16);
const UInt64 WS_CHILD = 0x40000000;
IntPtr hWnd = new WindowInteropHelper(this).Handle;
UInt64 iWindowStyle = GetWindowLong(hWnd, GWL_STYLE);
SetWindowLong(hWnd, GWL_STYLE, (iWindowStyle| WS_CHILD));

最后设置一下窗口的父窗口即可

1 2	IntPtr desktopHandle = SearchDesktopHandle(); SetParent(hWnd, desktopHandle);

完整代码

public partial class MainWindow : Window{
    [DllImport("user32.dll", SetLastError = true)]
    static extern UInt64 GetWindowLong(IntPtr hWnd, int nIndex);
    [DllImport("user32.dll")]
    static extern int SetWindowLong(IntPtr hWnd, int nIndex, UInt64 dwNewLong);
    [DllImport("user32.dll")]
    static extern IntPtr GetDesktopWindow();
    [DllImport("user32.dll")]
    static extern IntPtr SetParent(IntPtr hWndChild, IntPtr hWndNewParent);
    [DllImport("user32.dll", SetLastError = true)]
    static extern IntPtr FindWindow(string lpWindowClass, string lpWindowName);
    [DllImport("user32.dll", SetLastError = true)]
    static extern IntPtr FindWindowEx(IntPtr parentHandle, IntPtr childAfter, string className, string windowTitle);
    
    public static IntPtr SearchDesktopHandle() {
        IntPtr hRoot = GetDesktopWindow();
        IntPtr hShellDll = IntPtr.Zero;
        IntPtr hDesktop = FindWindowEx(hRoot, IntPtr.Zero, "WorkerW", String.Empty);
        while (true) {
            hShellDll = FindWindowEx(hDesktop, IntPtr.Zero, "SHELLDLL_DefView", String.Empty);
            if (hShellDll != IntPtr.Zero) {
                return hDesktop;
            }
            hDesktop = FindWindowEx(hRoot, hDesktop, "WorkerW", String.Empty);
        }
    	return IntPtr.Zero;
	}
    
    public MainWindow() {
        InitializeComponent();
    }
	
    private void MainWindow_onLoaded(object sender, EventArgs e) {
    	const int GWL_STYLE = (-16);
        const UInt64 WS_CHILD = 0x40000000;
        IntPtr hWnd = new WindowInteropHelper(this).Handle;
        UInt64 iWindowStyle = GetWindowLong(hWnd, GWL_STYLE);
        SetWindowLong(hWnd, GWL_STYLE, (iWindowStyle| WS_CHILD));

        IntPtr desktopHandle = Utils.SearchDesktopHandle();
        SetParent(hWnd, desktopHandle);     
    }
}