UWP 动态加载Resources问题

Question

定义的Resources资源汇集到APP.xaml里,都是静态的,要动态的只能如此

 ResourceDictionary newResourceDictionary = new ResourceDictionary();
                        newResourceDictionary.Source = new Uri("ms-appx:///Theme/ThemeDark.xaml", UriKind.RelativeOrAbsolute);
                        //newResourceDictionary_1.Source = new Uri("ms-appx:///Theme/StyleResources.xaml", UriKind.RelativeOrAbsolute);
                        Application.Current.Resources.MergedDictionaries.Clear();
                        Application.Current.Resources.MergedDictionaries.Add(newResourceDictionary);

如果要加载很多的XAML文件怎么办?我自己实现了下面的方法有时候有效有时候又无效,真的好奇怪,

public void LadingXaml()
        {
            ICollection<ResourceDictionary> tempRE = Application.Current.Resources.MergedDictionaries;
            Application.Current.Resources.MergedDictionaries.Clear();
            foreach (var item in tempRE)
            {
                Application.Current.Resources.MergedDictionaries.Add(item);
            }
            //await new MessageDialog(tempRE.Count.ToString()).ShowAsync();
        }

Answer 1

这一行tempRE是引用MergedDictionaries,在第二行它被清除了，所以这一行tempRE是空值，进不了foreach循环

 foreach (var item in tempRE) 

还有一种原因是ThemeDark.xaml，StyleResources.xaml里面的Key重复了

---

专注于.NET ERP/CRM开发框架，C/S架构，SQL Server + ORM(LLBL Gen Pro) + Infragistics WinForms

Answer 2

我的本意是想将现有的MergedDictionaries里的元素赋值给rempRE.然后再用foreach重新导入回去

ThemeDark.xaml里都是些Brush。没有KEY，StyleResources。xaml里只是定义了一些Control的公共属性，也没有定义KEY。听您这样一说我在最后的MsesageDialog输出确实Count是0

Answer 3

ResourceDictionary.CopyTo 方法

找到这个，但是有个重点这个方法：如果再次重建为 ResourceDictionary，则结果数组中将没有 MergedDictionaries。

ResourceDictionary[] tempRE = new ResourceDictionary[] { };
            //await new MessageDialog((tempRE.Count<ResourceDictionary>().ToString())).ShowAsync();
            Application.Current.Resources.MergedDictionaries.CopyTo(tempRE , 0);

会爆The specified index is out of bounds of the specified array

Answer 4

?????

Answer 5

刚刚试了下你的代码,不知道转成C#是不是对的.会报异常 An item with the same key has already been added.

 List<string> flies = new List<string>
        {
            "ms-appx:///Theme/StyleResources.xaml","ms-appx:///Theme/ThemeDark.xaml" ,"ms-appx:///Theme/ThemeLight.xaml"
        };

            var res = new ResourceDictionary();
            var appRs = Application.Current.Resources;
            
            foreach (var file in flies)
            {
                res.Clear();
                Application.LoadComponent(res, new Uri(file), ComponentResourceLocation.Application);
                foreach (var item in res)
                {
                    
                    appRs.Add(item.Key,item.Value);
                }
            }

Answer 6

?????

Answer 7

感谢了,真是快爆肝了,终于醒悟,ThemeDark和ThemeLight几乎都是同名的KEY只是值不同.

Answer 8

还是有点问题标题栏颜色改变不了,默认Light主题,切到Dark主题标题栏颜色还是Light的,我最开始的代码在调用处使用完全没这个问题.

调用处

#region 日间or夜间模式
                    if (RequestedTheme == ElementTheme.Light)
                    {

                        #region 另外一种载入
                        //newResourceDictionary = new ResourceDictionary();
                        //newResourceDictionary.Source = new Uri("ms-appx:///Theme/ThemeDark.xaml", UriKind.RelativeOrAbsolute);

                        //Application.Current.Resources.MergedDictionaries.Clear();
                        //Application.Current.Resources.MergedDictionaries.Add(newResourceDictionary);
                        #endregion
                        LightOrDark = false;
                        loadr.LadingXaml(LightOrDark);
                        L_DTxt.Text = "日间模式";
                        L_DFontIcon.Glyph = "\uE706";//该图标颜色为黑色月亮
                        RequestedTheme = ElementTheme.Dark;
                    }
                    else
                    {
                        #region 另外一种载入
                        //newResourceDictionary = new ResourceDictionary();

                        ////newResourceDictionary.Source = new Uri("ms-appx:///Theme/ThemeDark.xaml", UriKind.RelativeOrAbsolute);

                        //Application.Current.Resources.MergedDictionaries.Clear();
                        //Application.Current.Resources.MergedDictionaries.Add(newResourceDictionary);
                        #endregion

                        LightOrDark = true;
                        loadr.LadingXaml(LightOrDark);
                        L_DTxt.Text = "夜间模式";
                        L_DFontIcon.Glyph = "\uE708";//该图标颜色为白色太阳
                        RequestedTheme = ElementTheme.Light;

                    }
                    ChangTitBarColor();
                    #endregion
                    break;

方法体里面

  #region 新测试


            string tempTD = "ms-appx:///Theme/ThemeDark.xaml";
            string tempTL = "ms-appx:///Theme/ThemeLight.xaml";
            string tempSR = "ms-appx:///Theme/StyleResources.xaml";
        

            var res = new ResourceDictionary();
            var appRs = Application.Current.Resources;
            if (LightOrDark==false)
            {
                res.Clear();
                Application.LoadComponent(res, new Uri(tempTD,UriKind.RelativeOrAbsolute), ComponentResourceLocation.Application);
                foreach (var item in res)
                {
                    appRs.Add(item.Key, item.Value);
                }
            }
            else
            {
                res.Clear();
                Application.LoadComponent(res, new Uri(tempTL,UriKind.RelativeOrAbsolute), ComponentResourceLocation.Application);
                foreach (var item in res)
                {

                    appRs.Add(item.Key, item.Value);
                }
            }
            #endregion

还是会报An item with the same key has already been added.

Answer 9

 #region 新测试


            string tempTD = "ms-appx:///Theme/ThemeDark.xaml";
            string tempTL = "ms-appx:///Theme/ThemeLight.xaml";
            string tempSR = "ms-appx:///Theme/StyleResources.xaml";
        

            var res = new ResourceDictionary();
            var appRs = Application.Current.Resources.MergedDictionaries;
            if (LightOrDark==false)
            {
                appRs.Clear();
                res.Source = new Uri(tempTD);
                appRs.Add(res);
            }
            else
            {
                appRs.Clear();
                res.Source = new Uri(tempTL);
                appRs.Add(res);
            }
            #endregion

已经解决了

再次感谢,您的帮助,有时候一个问题转了牛角尖了,把简单的问题搞复杂了, - -|||