WPF PopUp的简单使用

<Window x:Class="WpfApp1.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:WpfApp1"
        mc:Ignorable="d"
        Title="MainWindow" Height="250" Width="400"
        FontFamily="Microsoft YaHei" FontWeight="ExtraLight" >

    <Window.Resources>
        
    </Window.Resources>
    <Border Margin="10" Background="White" CornerRadius="10">
        <Grid>
            <!--内容区-->
            <Button Width="50" Height="30" Content="ok" Name="PopButton" Click="PopButton_Click"/>
            <Popup x:Name="Pop" PopupAnimation="Slide" Width="180" Height="250" PlacementTarget="{Binding ElementName=PopButton}" Placement="Bottom" AllowsTransparency="True" StaysOpen="False">
                <Grid>
                    <Rectangle Fill="White" Margin="5" Opacity="0.8" RadiusY="2" RadiusX="2">
                        <Rectangle.Effect>
                            <DropShadowEffect Color="#FFBBBBBB" Direction="0" BlurRadius="15" RenderingBias="Quality" ShadowDepth="1"></DropShadowEffect>
                        </Rectangle.Effect>
                    </Rectangle>
                    <StackPanel Margin="15">
                        <TextBlock Text="设置" FontSize="14" Margin="0 0 0 5"/>

                    </StackPanel>
                </Grid>
            </Popup>
        </Grid>
        
    </Border>
</Window>

namespace WpfApp1
{
    /// <summary>
    /// MainWindow.xaml 的交互逻辑
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
        }

        private void PopButton_Click(object sender, RoutedEventArgs e)
        {
            Pop.IsOpen = true;//设置为打开状态
        }
    }
}

解决Popup控件跟随移动和始终位于最上层问题
1.重写popup控件

public class PopupEx : Popup
    {
        /// <summary>  
        /// 是否窗口随动，默认为随动（true）  
        /// </summary>  
        public bool IsPositionUpdate  
        {  
            get { return  (bool)GetValue(IsPositionUpdateProperty); }  
            set { SetValue(IsPositionUpdateProperty, value); }  
        }  

        public static readonly DependencyProperty  IsPositionUpdateProperty =  
            DependencyProperty.Register("IsPositionUpdate",  typeof(bool), typeof(PopupEx), new PropertyMetadata(true, new  PropertyChangedCallback(IsPositionUpdateChanged)));  

        private static void  IsPositionUpdateChanged(DependencyObject d,  DependencyPropertyChangedEventArgs e)  
        {  
            (d as PopupEx).pup_Loaded(d as PopupEx, null);  
        }  

        /// <summary>  
        /// 加载窗口随动事件  
        /// </summary>  
        public PopupEx()  
        {  
            this.Loaded += pup_Loaded;  
        }  

        /// <summary>  
        /// 加载窗口随动事件  
        /// </summary>  
        private void pup_Loaded(object sender, RoutedEventArgs  e)  
        {  
            Popup pup = sender as Popup;  
            var win = VisualTreeHelper.GetParent(pup);  
            while (win != null && (win as Window) == null)  
            {  
                win = VisualTreeHelper.GetParent(win);  
            }  
            if ((win as Window) != null)  
            {
                (win as Window).LocationChanged -=  PositionChanged;
                (win as Window).SizeChanged -= PositionChanged;
                if (IsPositionUpdate)
                {
                    (win as Window).LocationChanged +=  PositionChanged;
                    (win as Window).SizeChanged +=  PositionChanged;  
                }
            }  
        }  

        /// <summary>  
        /// 刷新位置  
        /// </summary>  
        private void PositionChanged(object sender, EventArgs e)  
        {
            try
            {
                var method =  typeof(Popup).GetMethod("UpdatePosition",  System.Reflection.BindingFlags.NonPublic |  System.Reflection.BindingFlags.Instance);
                if (this.IsOpen)
                {
                    method.Invoke(this, null);
                }
            }
            catch
            {
                return;
            }
        }  

        //是否最前默认为非最前（false）  
        public static DependencyProperty TopmostProperty =  Window.TopmostProperty.AddOwner(typeof(Popup), new  FrameworkPropertyMetadata(false, OnTopmostChanged));  
        public bool Topmost  
        {  
            get { return (bool)GetValue(TopmostProperty); }  
            set { SetValue(TopmostProperty, value); }  
        }  
        private static void OnTopmostChanged(DependencyObject  obj, DependencyPropertyChangedEventArgs e)  
        {  
            (obj as PopupEx).UpdateWindow();  
        }  

        /// <summary>  
        /// 重写拉开方法，置于非最前  
        /// </summary>  
        /// <param name="e"></param>  
        protected override void OnOpened(EventArgs e)  
        {  
            UpdateWindow();  
        }  

        /// <summary>  
        /// 刷新Popup层级  
        /// </summary>  
        private void UpdateWindow()  
        {  
            var hwnd =  ((HwndSource)PresentationSource.FromVisual(this.Child)).Handle;  
            RECT rect;  
            if (NativeMethods.GetWindowRect(hwnd, out rect))  
            {  
                NativeMethods.SetWindowPos(hwnd, Topmost ? -1 :  -2, rect.Left, rect.Top, (int)this.Width, (int)this.Height, 0);  
            }  
        }  

        [StructLayout(LayoutKind.Sequential)]  
        public struct RECT  
        {  
            public int Left;  
            public int Top;  
            public int Right;  
            public int Bottom;  
        }  
        #region P/Invoke imports & definitions  
        public static class NativeMethods  
        {  


            [DllImport("user32.dll")]  
            [return: MarshalAs(UnmanagedType.Bool)]  
            internal static extern bool GetWindowRect(IntPtr  hWnd, out RECT lpRect);  
            [DllImport("user32", EntryPoint = "SetWindowPos")]  
            internal static extern int SetWindowPos(IntPtr hWnd,  int hwndInsertAfter, int x, int y, int cx, int cy,  int wFlags);  
        }  
        #endregion  
    }

.在界面中使用

<local:PopupEx x:Name="pop1" Topmost="False"  StaysOpen="True"  PopupAnimation="Slide" AllowsTransparency="False"
                           PlacementTarget="{Binding  ElementName=popImg}" Placement="Left">
                        <local:PopupControl x:Name="pop_view"/>
                    </local:PopupEx>

                        
原文链接：https://blog.csdn.net/qq_43024228/article/details/110353099