WPF後臺動態呼叫樣式檔案,不用來回改App.g.cs
應用場合：如果您的WPF應用程式設定WPF執行一個例項程式碼後,App.xaml檔案中對樣式資源字典檔案的引用將失效.
解決辦法1：在App.xaml.cs檔案中用反射動態呼叫另外一個DLL專案中的樣式檔案即可
詳細操作介紹如下：
1、WPF設定只執行一個例項程式碼：
App.xaml檔案程式碼如下：
<Application.Resources>
<ResourceDictionary>
<ResourceDictionary.MergedDictionaries>
<ResourceDictionary Source="ButtonStyle.xaml"/>
</ResourceDictionary>
</Application.Resources>
</Application>
App.xaml.cs檔案程式碼如下：
//新增引用
using System.Diagnostics;
using System.IO;
using System.Reflection;
namespace WpfUI
{
/// <summary>
/// App.xaml 的互動邏輯
/// </summary>
public partial class App : Application
{
public App()
{
}
/// <summary>
/// 要設定App.xaml的檔案屬性中生成操作=無
/// </summary>
[STAThread]
public static void Main()
{
App myApp = new App();
myApp.ShutdownMode = ShutdownMode.OnExplicitShutdown;
myApp.Run();
}
private void Application_DispatcherUnhandledException(object sender, System.Windows.Threading.DispatcherUnhandledExceptionEventArgs e)
{
if (e.Exception is InvalidOperationException)
e.Handled = true;
}
protected override void OnStartup(StartupEventArgs e)
{
//獲取當前執行WPF程式的程序例項
Process process = Process.GetCurrentProcess();
//遍歷WPF程式的同名程序組
foreach (Process p in Process.GetProcessesByName(process.ProcessName))
{
if (p.Id != process.Id && (p.StartTime - process.StartTime).TotalMilliseconds <= 0)
{
p.Kill();//關閉程序
return;
}
}
base.OnStartup(e);
//啟動登陸窗體,
MainWindow myWindow = new MainWindow();
myWindow.Show();
}
}
}
2、ButtonStyle.xaml樣式檔案內容如下：
<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
<!--按鈕樣式-->
<Style x:Key="RedButtonStyle" TargetType="{x:Type Button}">
<Setter Property="Foreground" Value="Red"/>
<Setter Property="Background" Value="Silver"/>
<Setter Property="Height" Value="23"/>
</Style>
</ResourceDictionary>
3、MainWindow.xaml檔案內容如下：
<Window x:Class="WpfUI.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="MainWindow" Height="350" Width="525">
<Grid>
<Button Content="Button" Style="{StaticResource RedButtonStyle}" Height="23" HorizontalAlignment="Left" Margin="102,66,0,0" Name="button1" VerticalAlignment="Top" Width="75" />
</Grid>
</Window>
4、執行程式後發現按鈕樣式RedButtonStyle總提示找不到
5、 解決辦法如下：
第一步: 新建一個Windows--類庫專案WpfThems,將ButtonStyle.xaml拷貝過去, 設定ButtonStyle.xaml檔案的屬性生成操作為 "Page",之後生成WpfThems.dll檔案
第二步:在當前專案WpfUI中新增WpfThems專案引用
第三步:修改App.xaml.cs 檔案程式碼：新增一個函式LoadStyleResource並修改OnStartup函式內容。修改後的App.xaml.cs檔案內容如下：
using System;
using System.Collections.Generic;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Windows;
//新增引用
using System.Diagnostics;
using System.IO;
using System.Reflection;
namespace WpfUI
{
/// <summary>
/// App.xaml 的互動邏輯
/// </summary>
public partial class App : Application
{
public App()
{
}
/// <summary>
/// 設定WpfUI專案中的App.xaml的檔案屬性中"生成操作"為"無"
/// 設定WpfThemes專案中的ButtonStyle.xaml的檔案屬性中"生成操作"為"Page"
/// </summary>
[STAThread]
public static void Main()
{
App myApp = new App();
myApp.ShutdownMode = ShutdownMode.OnExplicitShutdown;
myApp.Run();
}
/// <summary>
/// 過載應用程式啟動函式
/// </summary>
/// <param name="e"></param>
protected override void OnStartup(StartupEventArgs e)
{
//獲取當前執行WPF程式的程序例項
Process process = Process.GetCurrentProcess();
//遍歷WPF程式的同名程序組
foreach (Process p in Process.GetProcessesByName(process.ProcessName))
{
if (p.Id != process.Id && (p.StartTime - process.StartTime).TotalMilliseconds <= 0)
{
p.Kill();//關閉程序
return;
}
}
base.OnStartup(e);
//動態呼叫樣式檔案
LoadStyleResource();
//啟動窗體
MainWindow myWindow = new MainWindow();
myWindow.Show();
}
private void LoadStyleResource()
{
Assembly assembly = Assembly.LoadFrom("WpfThemes.dll");
string packUri = @"/WpfThemes;component/ButtonStyle.xaml";
ResourceDictionary myResourceDictionary = Application.LoadComponent(new Uri(packUri, UriKind.Relative)) as ResourceDictionary;
this.Resources.MergedDictionaries.Add(myResourceDictionary);
}
}
}
解決辦法2：在需要引用樣式的窗體的xaml檔案中新增對指定樣式檔案的引用
<Window.Resources>
<ResourceDictionary>
<ResourceDictionary.MergedDictionaries>
<ResourceDictionary Source="ButtonStyle.xaml"/>
</ResourceDictionary.MergedDictionaries>
</ResourceDictionary>
</Window.Resources>