c#始终在顶部例外

我用了这个密码

namespace WindowsFormsApplication52
{
public partial class Form1 : Form
{
    static readonly IntPtr HWND_TOPMOST = new IntPtr(-1);
    static readonly IntPtr HWND_NOTOPMOST = new IntPtr(-2);
    static readonly IntPtr HWND_TOP = new IntPtr(0);
    static readonly IntPtr HWND_BOTTOM = new IntPtr(1);
    const UInt32 SWP_NOSIZE = 0x0001;
    const UInt32 SWP_NOMOVE = 0x0002;
    const UInt32 TOPMOST_FLAGS = SWP_NOMOVE | SWP_NOSIZE;

    [DllImport("user32.dll")]
    [return: MarshalAs(UnmanagedType.Bool)]
    public static extern bool SetWindowPos(IntPtr hWnd, IntPtr hWndInsertAfter, int X, int Y, int cx, int cy, uint uFlags);

    public Form1()
    {
        InitializeComponent();
    }

    private void Form1_Load(object sender, EventArgs e)
    {
        SetWindowPos(this.Handle, HWND_TOPMOST, 0, 0, 0, 0, TOPMOST_FLAGS);
    }
}

但有些应用程序仍然处于领先地位。我离开了任务管理器，但有时我想重新开始。我无法运行。我怎么修理它

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一些最顶端的窗口比最顶端的窗口更顶端，因为它们只是到达顶端：）@AlexeiLevenkov creative solutions:）为什么要使用该代码？？只需设置表单的最高属性，而不是重新发明轮子<代码>this.topmest=true它不工作。我还是试着关上它