选择按名称刷

Question

我有一个笔刷的确切名称(AliceBlue, OrangeRed等)，我想知道是否有可能通过这个字符串选择笔刷。Brushes是一个静态集合，我真的不知道如何做到这一点。我认为在正常的集合中，可以通过选择Linq项目的name属性来完成，但这里似乎不起作用。

Answer 1

使用系统中的BrushConverter。ComponentModel名称空间:

BrushConverter conv = new BrushConverter();

你可以使用一个颜色名称:

SolidColorBrush brush = conv.ConvertFromString("Red") as SolidColorBrush;

你也可以使用RGB值:

SolidColorBrush brush = conv.ConvertFromString("#0000FF") as SolidColorBrush;

Answer 2

使用反射很容易做到:

// TODO: Validation :)
Brush brush = (Brush) typeof(Brushes).GetProperty(name)
                                     .GetValue(null);

或者，您可以使用反射一次来填充字典:

Dictionary<string, Brush> = 
    typeof(Brushes).GetProperties(BindingFlags.Public |
                                  BindingFlags.Static)
                   .ToDictionary(p => p.Name,
                                 p => (Brush) p.GetValue(null));

Answer 3

From BrushConverter class (MSDN):

使用这个类将字符串转换为SolidColorBrush或一个ImageBrush。有关语法信息，请参阅这些类型页面。这门课是通常由解析器用于将属性字符串转换为笔刷。

SolidColorBrush redBrush = (SolidColorBrush)new BrushConverter().ConvertFromString("Red");

您可以创建自己的StringToBrushConverter，并通过传递字符串颜色变量并返回SolidColorBrush变量，在其Convert方法中使用上述代码。

Answer 4

我有两个解决方案。

一个使用SolidColorBrush属性，并设置为你想要的属性，如下所示。

另一个是使用转换与BrushConverter类。

<Window x:Class="WpfApplication1.DynamicSorting"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
       xmlns:local="clr-namespace:WpfApplication1"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="DynamicSorting" Height="329" Width="610">
    <Window.Resources>
        <local:StringToBrushConverter x:Key="texttobrush"/>
    </Window.Resources>
    <Grid Background="{Binding SelectedBrush,UpdateSourceTrigger=PropertyChanged,Mode=TwoWay}">
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="242*" />
            <ColumnDefinition Width="346*" />
        </Grid.ColumnDefinitions>
        <ComboBox Height="35" SelectedItem="{Binding SelectedBrush,Mode=TwoWay}"  ItemsSource="{Binding AllBrushes}"  HorizontalAlignment="Left" Margin="25,32,0,0" x:Name="comboBox1" VerticalAlignment="Top" Width="143" />
    </Grid>
</Window>

 public partial class DynamicSorting : Window, INotifyPropertyChanged
    {
        public DynamicSorting()
        {
            InitializeComponent();
            if (FilesList == null)
                FilesList = new ObservableCollection<FileInfo>();
            var files = new System.IO.DirectoryInfo("C:\Windows\System32\").GetFiles();
            foreach (var item in files)
            {
                FilesList.Add(item);
            }

            if (AllBrushes == null)
                AllBrushes = new ObservableCollection<string>();
            Type t = typeof(Brushes);
            var props = t.GetProperties();
            foreach (var item in props)
            {
                AllBrushes.Add(item.Name);
            }


            this.DataContext = this;

        }
        private SolidColorBrush _SelectedBrush;
        public SolidColorBrush SelectedBrush
        {
            get { return _SelectedBrush; }
            set
            {
                _SelectedBrush = value;
                if (PropertyChanged != null)
                    PropertyChanged(this, new PropertyChangedEventArgs("SelectedBrush"));
            }
        }
        public ObservableCollection<FileInfo> FilesList { get; set; }
        public ObservableCollection<string> AllBrushes { get; set; }
        public event PropertyChangedEventHandler PropertyChanged;
    }
    public class StringToBrushConverter : IValueConverter
    {
        public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {
            if (value == null)
                return Brushes.Transparent;
            var colortext = value.ToString();
            var BrushType = typeof(Brushes);
            var brush = BrushType.GetProperty(colortext);
            if (brush != null)
                return brush;
            return Brushes.Transparent;
        }
        public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {
            throw new NotImplementedException();
        }
    }