根據WP7中的黑暗與光明主題加載圖像

Question

在我當前的Windows Phone 7應用程序中，我們要使用兩個主題：“黑暗與光明”，我們還在應用程序中使用了一些全景和樞軸控件。 每個控件對於每個黑暗和明亮主題都有不同的圖像。

為此，我在項目中制作了兩個單獨的主題。 但是，我無法加載該主題的圖像。 有人可以建議我如何根據主題是深色還是淺色從主題加載圖像？

Answer 1

如果僅顯示圖像，則可以創建一個ValueConverter來確定主題：

// 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();
    }
}

並在您的xaml中：

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

如果將圖像放在按鈕中，並且圖像僅使用背景色和前景色（黑色和白色），則可以使用一種可以更改顏色的樣式。

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

和樣式：

<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

您可以使用以下代碼片段確定主題，並相應地設置圖像。

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

您也可以在這里查看更多詳細信息。

Answer 3

我猜更好的方法是將兩個單獨的主題分別設置為淺色和深色主題，然后按主題可見性位決定應用程序的加載。

在我們的主題中，我們可以像這樣加載圖像

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