WPF 找不到App.xaml里面的样式的问题

Posted 2023-04-25

我把样式写在App.xaml里面,没运行时候能看到效果,运行时候要报错:“在“System.Windows.StaticResourceExtension”上提供值时引发了异常。怎么解决啊

参考技术A 重新编译再试看下！一般没运行时能看到，运行的时候也应当看到的。你样式的key有没有设置正确呢？如果把app里的样式剪切到page的resource里运行还会报错么？本回答被提问者采纳 参考技术B 样式定义和使用的代码段都贴出来看看才知道。

WPF动态创建消息弹窗，2秒自动消失

样式代码，放入App.xaml中

App.xaml

<Application x:Class="WpfSnqkGasAnalysis.App"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:local="clr-namespace:WpfSnqkGasAnalysis"
             StartupUri="Login.xaml">
    <Application.Resources>
        <ResourceDictionary Source="Dictionary1.xaml" />
    </Application.Resources>
</Application>

Dictionary1.xaml，消息框样式

  <!--消息提示框-->
    <Style x:Key="TextBlock_Alert" TargetType="TextBlock">
        <Setter Property="Background" Value="Lime"></Setter>
        <Setter Property="Padding" Value="20,10"></Setter>
        <Setter Property="FontSize" Value="18"></Setter>
         <Setter Property="Margin" Value="4"></Setter> 
        <Setter Property="HorizontalAlignment" Value="Center"></Setter>
        <Setter Property="VerticalAlignment" Value="Top"></Setter>
        <Setter Property="TextWrapping" Value="Wrap"></Setter>
        <!--<Setter Property="Panel.ZIndex" Value="3000"></Setter>-->        
    </Style>

后端代码

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Controls.Primitives;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Threading;



namespace WpfSnqkGasAnalysis

    /// <summary>
    /// 消息框封装，消息2秒后消失
    /// </summary>
    /// 创建时间：2022年11月30日15:08:25。
    public static class ShowAlertHelpter
    
         
        //上一次显示的top位置
        static double lastTop = 0;
        static double lastLeft = 0;

        //上一次显示时间
        static DateTime lastShowTime = DateTime.Now;

        /// <summary>
        /// 提示消息。消息2秒后消失
        /// </summary>
        /// <param name="msg">消息</param>        
        /// <param name="alwaysShow">是否一直显示</param>
        public static void ShowAlert(string msg,  bool alwaysShow = false)
        
            //Grid grid = Application.Current.Windows[0].FindName("mainGrid") as Grid;
            Grid grid = Application.Current.Windows[0].Content as Grid;
            if (grid == null)
            
                return;
            

            //Grid grid = null;
            //if (page is Window)
            //
            //    Window window = (Window)page;
            //    grid = window.Content as Grid;
            //
            //else if (page is Page)
            //
            //    Page args = (Page)page;
            //    grid = args.Content as Grid;
            //
            //else if (page is Grid)
            //
            //    grid = page as Grid;
            //

            Application.Current.Dispatcher.BeginInvoke(
               () =>
            
                //Popup使消息在最前面显示
                Popup popup = new Popup();
                popup.PopupAnimation = PopupAnimation.Fade;//渐入
                popup.AllowsTransparency = true;//设置Popup透明
                popup.Margin = new Thickness(10);
                popup.VerticalOffset = 200;
                popup.HorizontalOffset = 600;
                popup.HorizontalAlignment = HorizontalAlignment.Center;
                //popup.IsOpen = false;
                popup.IsOpen = true;
                popup.ToolTip = "点击关闭";

                TextBlock textBlock = new TextBlock();
                textBlock.Text = msg;
                textBlock.Style = (System.Windows.Style)grid.FindResource("TextBlock_Alert");

                //边框阴影
                System.Windows.Media.Effects.DropShadowEffect effect = new System.Windows.Media.Effects.DropShadowEffect();
                effect.BlurRadius = 4;
                effect.Color = Color.FromRgb(196, 196, 196);
                textBlock.Effect = effect;

                if (lastTop > 0 && (DateTime.Now - lastShowTime).TotalSeconds < 3)
                
                    //字符多，增加偏移
                    double space = 50d;
                    if (msg.Length > 22)
                    
                        space = 70d;
                    
                    popup.HorizontalOffset = lastLeft + space;
                    popup.VerticalOffset = lastTop + space;
                

                //一直显示消息
                if (alwaysShow || msg.Contains("失败") || msg.Contains("异常") || msg.Contains("出错"))
                
                    textBlock.Background = Brushes.Orchid;//红色背景
                    goto SKIP_END;
                

                //消息提示自动消失
                DispatcherTimer timer = new DispatcherTimer();
                timer.Interval = TimeSpan.FromMilliseconds(2000);
                timer.Tick += (s, e) =>
                
                    grid.Children.Remove(popup);
                    timer.Stop();

                    if (lastTop > 500)
                    
                        lastTop = 0;
                        lastLeft = -200;
                    
                ;
                timer.Start();

            SKIP_END:
                lastTop = popup.VerticalOffset;
                lastLeft = popup.HorizontalOffset;
                lastShowTime = DateTime.Now;

                popup.Child = textBlock;
                grid.Children.Add(popup);

                //点击就移除
                popup.MouseLeftButtonUp += (s, e) =>
                
                    grid.Children.Remove(popup);
                ;

            );
        

    

调用显示消息

private void btnSearch_Click(object sender, RoutedEventArgs e)

	ShowAlertHelpter.ShowAlert("操作成功");