WPF:在运行时从 App.xaml 更改资源(颜色) [英] WPF: Changing Resources (colors) from the App.xaml during runtime

问题描述

我试图通过允许用户从颜色选择器对话框中选择颜色，然后实时更改应用程序的样式(使用 DynamicResource)来使我的应用程序更具可定制性

I am trying to make my application more customizable by allowing users to pick a color from a Color Picker dialog, and then changing the style of the application in real time (with DynamicResource)

如何更改驻留在 app.xaml 中的特定资源?

How do I go about in changing specific resources that reside in the app.xaml ?

我尝试过这样的事情，但没有运气(只是一个测试):

I have tried something like this but no luck (just a test):

var colorDialog = new CustomControls.ColorPickerDialog();
var dResult = colorDialog.ShowDialog();
var x = Application.Current.Resources.Values.OfType<LinearGradientBrush>().First();
x = new LinearGradientBrush();
x.GradientStops.Add(new GradientStop(colorDialog.SelectedColor,1));

这是 app.xaml 文件的摘录:

<Application.Resources>
    <LinearGradientBrush x:Key="HeaderBackground" StartPoint="0.5,0" EndPoint="0.5,1">
        <GradientStop Color="#82cb02" Offset="1"/>
        <GradientStop Color="#82cb01" Offset="0.2"/>
        <GradientStop Color="#629a01" Offset="0.5"/>
    </LinearGradientBrush>
</Application.Resources>

让这种形式的可定制性(基本上只是改变一些颜色)应用于应用程序的最佳方式是什么?

[更新]

我刚刚从之前提出的问题中找到了这个答案，并尝试了它但我得到了相同的 InvalidOperationException 异常 Petoj 在给定答案的评论中提到.这是答案中的示例代码:

I just found this answer from a previous question that was asked, and tried it but I am getting the same InvalidOperationException exception Petoj mentioned in the comments for the given answer. Here is the sample code from the answer:

Xaml:

<LinearGradientBrush x:Key="MainBrush" StartPoint="0,0.5" EndPoint="1,0.5" >
    <GradientBrush.GradientStops>
        <GradientStop Color="Blue" Offset="0" />
        <GradientStop Color="Black" Offset="1" />
    </GradientBrush.GradientStops>
</LinearGradientBrush>

C#:

LinearGradientBrush myBrush = FindResource("MainBrush") as LinearGradientBrush;
myBrush.GradientStops[0].Color = Colors.Red;

推荐答案

您似乎正在尝试进行某种换肤?

It looks like you're trying to do some sort of skinning?

我建议在包含在单独文件中的资源字典中定义资源.然后在代码中(App.cs 加载默认值，然后在其他地方进行更改)，您可以这样加载资源:

I'd recommend defining the resources in a Resource Dictionary contained in a separate file. Then in code (App.cs to load a default, then elsewhere to change) you can load the resources as so:

//using System.Windows
ResourceDictionary dict = new ResourceDictionary();
dict.Source = new Uri("MyResourceDictionary.xaml", UriKind.Relative);

Application.Current.Resources.MergedDictionaries.Add(dict);

您也可以在 App.xaml 中定义默认资源字典并在代码中卸载它就好了.

You could also define the default resource dictionary in App.xaml and unload it in code just fine.

使用 MergedDictionaries 对象来更改您在运行时使用的字典.就像快速改变整个界面的魅力一样.

Use the MergedDictionaries object to change the dictionary you're using at runtime. Works like a charm for changing an entire interface quickly.

这篇关于WPF:在运行时从 App.xaml 更改资源(颜色)的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！