WPF整理-使用ResourceDictionary管理Logical Resources

“Logical resources may be of various types, such as brushes, geometries, styles, and templates.
Placing all those resources in a single file such as App.xaml hinders maintainability. A better
approach would be to separate resources of different types (or based on some other criteria) to
their own files. Still, they must be referenced somehow from within a common file such as App.
xaml so they are recognized.”

为了增加资源文件的可维护性，我们应该使用ResourceDictionary对资源进行：分类、汇总。

如何实现呢？举个例子

1.新建一个WPF Application，在Application中添加一个New Item，选择ResourceDictionary。

譬如，命名为Brushes.xaml，我们用它来存放一些笔刷。打开，我们添加一个笔刷如下：

Brushes.xaml:

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
    <LinearGradientBrush EndPoint="1,0" x:Key="brush1">
        <GradientStop Color="Violet" Offset="0" />
        <GradientStop Color="Orange" Offset=".7" />
        <GradientStop Color="Brown" Offset="1" />
    </LinearGradientBrush>
</ResourceDictionary>

2.在App.xaml中Merge则个Resource。
“Open App.xaml. We need to merge external resource dictionaries into the main
application dictionary.”

打开App.xaml，添加如下内容：

<Application x:Class="ManagingLogicalResources.App"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             StartupUri="MainWindow.xaml">
    <Application.Resources>
        <ResourceDictionary>
            <ResourceDictionary.MergedDictionaries>
                <ResourceDictionary Source="Brushes.xaml"/>
            </ResourceDictionary.MergedDictionaries>
        </ResourceDictionary>
    </Application.Resources>
</Application>

3.这样我们就可以在页面中正常使用了。

<Window x:Class="ManagingLogicalResources.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>
        <Ellipse Fill="{StaticResource brush1}"/>
    </Grid>
</Window>

效果如下：

 -----------------------------------

在实际开发中更常用的做法是：直接在使用的View内部Merge。

<Window x:Class="WPFMergedDicitonary.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">
    <Window.Resources>
        <ResourceDictionary>
            <ResourceDictionary.MergedDictionaries>
                <ResourceDictionary Source="Brushes.xaml"/>
            </ResourceDictionary.MergedDictionaries>
        </ResourceDictionary>
    </Window.Resources>
    <Grid>
        <Ellipse Fill="{StaticResource brush1}"/>
    </Grid>
</Window>

效果同上，如下：