C# SolidColorBrush 到我的转换器类

Question

我有一个 SolidColorBrush 类型的对象，它拥有 一个 SolidColorBrush。

现在我有一个绑定到列表的 dataGrid 转换器。 此 dataGrid 中的每一行都将由我拥有的转换器着色。

一切正常，但我怎样才能返回我的 SolidColorBrush 对象，而不是例如静态“Brushes.Red”。

我的转换器：

[ValueConversion(typeof(MainWindow.eErrorLevel), typeof(Brush))]
public class TypeToColourConverter : IValueConverter
{
    #region IValueConverter Members
    public object Convert(object value, Type targetType, object parameter,
        System.Globalization.CultureInfo culture)
    {
        MainWindow.eErrorLevel errorLevel = (MainWindow.eErrorLevel)value;



        switch (errorLevel)
        {
            case MainWindow.eErrorLevel.Information:
                return Brushes.Red;


            case MainWindow.eErrorLevel.Warning:
                return Brushes.Yellow;

            case MainWindow.eErrorLevel.Error:
                return Brushes.Red;

        }

        return Brushes.Gray;
    }

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

    #endregion
}

我的转换器不在主窗口中，如果这很重要的话 我的 MainWindow 中的我的 SolidColorBrush 对象是公开的：

public CurrentColor CurrentColors = new CurrentColor();



    public class CurrentColor
    {
        public SolidColorBrush ERROR { get; set; }
        public SolidColorBrush WARNING { get; set; }
        public SolidColorBrush INFORMATION { get; set; }
    }

编辑：我的画笔可以由用户自己动态设置

EDIT2：现在它的工作谢谢大家:)

Answer 1

假设这些颜色在运行时不会改变，您可以将画笔声明为转换器上方的资源，并为每个画笔向转换器添加属性，如下所示：

将您的转换器修改为：

[ValueConversion(typeof(MainWindow.eErrorLevel), typeof(Brush))]
public class TypeToColourConverter : IValueConverter
{
    #region IValueConverter Members
    public object Convert(object value, Type targetType, object parameter,
        System.Globalization.CultureInfo culture)
    {
        MainWindow.eErrorLevel errorLevel = (MainWindow.eErrorLevel)value;

        switch (errorLevel)
        {
            case MainWindow.eErrorLevel.Information:
                return Error;


            case MainWindow.eErrorLevel.Warning:
                return Warning;

            case MainWindow.eErrorLevel.Error:
                return Information;

        }

        return Normal;
    }

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

    #endregion

    public Brush Normal { get; set; }

    public Brush Error { get; set; }

    public Brush Warning { get; set; }

    public Brush Information { get; set; }
}

修改您的 XAML（无论您的转换器添加到何处）：

<SolidColorBrush x:Key="Normal" Color="#FFAAAAAA"/>
<SolidColorBrush x:Key="Error" Color="#FFFF0000"/>
<SolidColorBrush x:Key="Warning" Color="#FF00FF00"/>
<SolidColorBrush x:Key="Information" Color="#FF0000FF"/>

<local:TypeToColourConverter x:Key="TypeToColourConverter" Normal="{StaticResource Normal}" Error="{StaticResource Error}" Warning="{StaticResource Warning}" Information="{StaticResource Information}" />

这对设计师来说非常“友好”（即所有这些颜色都可以在 Blend 中更改）并且易于维护。

希望对你有帮助。

Answer 2

就像我在我的 cmets 中所说的，这是一个示例，将其作为转换器参数传递，可能还有其他选择：

XAML

<Window x:Class="WpfApplicationTestColorConverter.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:WpfApplicationTestColorConverter"
        mc:Ignorable="d"
        Title="MainWindow" Height="350" Width="525">
    <Window.Resources>
        <local:ErrorColors x:Key="Colors" />
        <local:TypeToColourConverter x:Key="ColorConverter" />
    </Window.Resources>
    <Grid>
        <ListBox x:Name="ListBox1" ItemsSource="{Binding MyObjects}">
            <ListBox.ItemTemplate>
                <DataTemplate>
                    <TextBlock 
                        Text="{Binding Title}" 
                        Background="{Binding ErrorLevel, 
                            Converter={StaticResource ColorConverter}, 
                            ConverterParameter={StaticResource Colors}}" />
                </DataTemplate>
            </ListBox.ItemTemplate>
        </ListBox>
    </Grid>
</Window>

---

隐藏代码

public partial class MainWindow : Window
{
    public ObservableCollection<MyObject> MyObjects { get; } = new ObservableCollection<MyObject>();

    public MainWindow()
    {
        InitializeComponent();
        DataContext = this;

        // find the (static)resource
        var colors = (ErrorColors)FindResource("Colors");
        colors.ERROR = new SolidColorBrush(Colors.Red);
        colors.WARNING = new SolidColorBrush(Colors.Orange);
        colors.INFORMATION = new SolidColorBrush(Colors.Lime);

        // Add objects to the list
        MyObjects.Add(new MyObject { Title = "This is an error", ErrorLevel = ErrorLevel.Error });
        MyObjects.Add(new MyObject { Title = "This is a warning", ErrorLevel = ErrorLevel.Warning });
        MyObjects.Add(new MyObject { Title = "This is information", ErrorLevel = ErrorLevel.Information });
    }
}

---

转换器

[ValueConversion(typeof(ErrorLevel), typeof(Brush))]
public class TypeToColourConverter : IValueConverter
{
    #region IValueConverter Members
    public object Convert(object value, Type targetType, object parameter,
        System.Globalization.CultureInfo culture)
    {
        if (!(value is ErrorLevel))
            return Brushes.Gray;

        if (!(parameter is ErrorColors))
            return Brushes.Gray;

        var lvl = (ErrorLevel)value;
        var currentColor = (ErrorColors)parameter;

        switch (lvl)
        {
            case ErrorLevel.Information:
                return currentColor.INFORMATION;


            case ErrorLevel.Warning:
                return currentColor.WARNING;

            case ErrorLevel.Error:
                return currentColor.ERROR;

        }

        return Brushes.Gray;
    }

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

    #endregion
}

---

public class ErrorColors
{
    public SolidColorBrush ERROR { get; set; }
    public SolidColorBrush WARNING { get; set; }
    public SolidColorBrush INFORMATION { get; set; }
}

---

public enum ErrorLevel
{
    Error,
    Warning,
    Information
}

---

public class MyObject
{
    public string Title { get; set; }
    public ErrorLevel ErrorLevel { get; set; }
}

---

结果：