根据WP7中的黑暗与光明主题加载图像

Question

在我当前的Windows Phone 7应用程序中，我们要使用两个主题：“黑暗与光明”，我们还在应用程序中使用了一些全景和枢轴控件。 每个控件对于每个黑暗和明亮主题都有不同的图像。

为此，我在项目中制作了两个单独的主题。 但是，我无法加载该主题的图像。 有人可以建议我如何根据主题是深色还是浅色从主题加载图像？

Answer 1

如果仅显示图像，则可以创建一个ValueConverter来确定主题：

// Assumes a dark theme image is passed in the parameter variable 
public class ImageThemeValueConverter : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        if(parameter == null) return null;

        Visibility darkBackgroundVisibility = 
            (Visibility)Application.Current.Resources["PhoneDarkThemeVisibility"];

        if (darkBackgroundVisibility == Visibility.Visible)
        {
            return new Uri(parameter.ToString();
        }
        else
        {
            string path = parameter.ToString();
            path = System.IO.Path.GetDirectoryName(path) + System.IO.Path.GetFileNameWithoutExtension(path) + ".light"+System.IO.Path.GetExtension(path);
            return new Uri(path);
        }
    }

    public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        throw new NotImplementedException();
    }
}

并在您的xaml中：

<Image Source="{Binding Converter={StaticResource ImageThemeValueConverter}, ConverterParameter=Images/ThemeImage.png}"/>

如果将图像放在按钮中，并且图像仅使用背景色和前景色（黑色和白色），则可以使用一种可以更改颜色的样式。

<Button Style="{StaticResource PhoneButton}">
    <ImageBrush ImageSource="/Images/appbar.save.png" Stretch="None"/>
</Button>

和样式：

<Style TargetType="Button" x:Key="PhoneButton">
    <Setter Property="Width" Value="48"/>
    <Setter Property="Height" Value="48"/>
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="Button">
                <Grid>
                    <VisualStateManager.VisualStateGroups>
                        <VisualStateGroup x:Name="CommonStates">
                            <VisualState x:Name="Normal"/>
                            <VisualState x:Name="MouseOver">
                                <Storyboard>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="(FrameworkElement.HorizontalAlignment)" Storyboard.TargetName="ContentContainer">
                                        <DiscreteObjectKeyFrame KeyTime="0">
                                            <DiscreteObjectKeyFrame.Value>
                                                <HorizontalAlignment>Stretch</HorizontalAlignment>
                                            </DiscreteObjectKeyFrame.Value>
                                        </DiscreteObjectKeyFrame>
                                    </ObjectAnimationUsingKeyFrames>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="(FrameworkElement.VerticalAlignment)" Storyboard.TargetName="ContentContainer">
                                        <DiscreteObjectKeyFrame KeyTime="0">
                                            <DiscreteObjectKeyFrame.Value>
                                                <VerticalAlignment>Stretch</VerticalAlignment>
                                            </DiscreteObjectKeyFrame.Value>
                                        </DiscreteObjectKeyFrame>
                                    </ObjectAnimationUsingKeyFrames>
                                </Storyboard>
                            </VisualState>
                            <VisualState x:Name="Pressed">
                                <Storyboard>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background" Storyboard.TargetName="ContentContainer">
                                        <DiscreteObjectKeyFrame KeyTime="0" Value="{StaticResource PhoneBackgroundBrush}"/>
                                    </ObjectAnimationUsingKeyFrames>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Fill" Storyboard.TargetName="Border">
                                        <DiscreteObjectKeyFrame KeyTime="0" Value="{StaticResource PhoneForegroundBrush}"/>
                                    </ObjectAnimationUsingKeyFrames>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Stroke" Storyboard.TargetName="Border">
                                        <DiscreteObjectKeyFrame KeyTime="0" Value="{StaticResource PhoneForegroundBrush}"/>
                                    </ObjectAnimationUsingKeyFrames>
                                </Storyboard>
                            </VisualState>
                            <VisualState x:Name="Disabled">
                                <Storyboard>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background" Storyboard.TargetName="ContentContainer">
                                        <DiscreteObjectKeyFrame KeyTime="0" Value="{StaticResource PhoneDisabledBrush}"/>
                                    </ObjectAnimationUsingKeyFrames>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Stroke" Storyboard.TargetName="Border">
                                        <DiscreteObjectKeyFrame KeyTime="0" Value="{StaticResource PhoneDisabledBrush}"/>
                                    </ObjectAnimationUsingKeyFrames>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Fill" Storyboard.TargetName="Border">
                                        <DiscreteObjectKeyFrame KeyTime="0" Value="Transparent"/>
                                    </ObjectAnimationUsingKeyFrames>
                                </Storyboard>
                            </VisualState>
                        </VisualStateGroup>
                    </VisualStateManager.VisualStateGroups>
                    <Grid>
                        <Ellipse x:Name="Border" Fill="{TemplateBinding Background}" Canvas.Left="0" Stretch="Fill" 
                                    StrokeThickness="3" StrokeLineJoin="Round" Stroke="{TemplateBinding BorderBrush}"/>
                        <Grid x:Name="ContentContainer" OpacityMask="{TemplateBinding Content}" Background="{TemplateBinding Foreground}"/>
                    </Grid>
                </Grid>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

Answer 2

您可以使用以下代码片段确定主题，并相应地设置图像。

if ((double)Application.Current.Resources["PhoneDarkThemeOpacity"] == 1)
{
  //Dark Theme
}
else
{
  //Light Theme
}

您也可以在这里查看更多详细信息。

Answer 3

我猜更好的方法是将两个单独的主题分别设置为浅色和深色主题，然后按主题可见性位决定应用程序的加载。

在我们的主题中，我们可以像这样加载图像

<BitmapImage x:Key="SearchImage" UriSource="/Images/searchIcon.png" />