如何使用一个转换器设置SystemColors.HighlightBrushKey在WPF [英] How to set the SystemColors.HighlightBrushKey in WPF with a Converter
问题描述
我我尝试设置SystemColors.HighlightBrushKey总是比所选行的背景暗一点。
因此，即时通讯使用这种code：
I im trying to set the SystemColors.HighlightBrushKey always a bit darker than the Background of the selected Row. Therefore im using this Code:
App.xaml中：
App.xaml:
<WPFTests2:SelectionBackgroundConverter x:Key="SelectionBackgroundConverter"/>
<SolidColorBrush x:Key="{x:Static SystemColors.HighlightBrushKey}" Color="{Binding Background, Converter={StaticResource SelectionBackgroundConverter}}"/>
</Application.Resources>
Window1.xaml：
Window1.xaml:
<Window x:Class="WPFTests2.Window1"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="Window1" Height="300" Width="300" Loaded="Window_Loaded">
<Grid>
<ListBox x:Name="LB" HorizontalAlignment="Stretch" VerticalAlignment="Stretch"/>
</Grid>
Window1.xaml.cs：
Window1.xaml.cs:
using System;
using System.Globalization;
using System.Windows;
using System.Windows.Data;
using System.Windows.Media;
namespace WPFTests2
{
/// <summary>
/// Interaction logic for Window1.xaml
/// </summary>
public partial class Window1 : Window
{
public Window1()
{
InitializeComponent();
}
private void Window_Loaded(object sender, RoutedEventArgs e)
{
LB.Items.Add("Text1");
LB.Items.Add("Text2");
LB.Items.Add("Text3");
LB.Items.Add("Text4");
LB.Items.Add("Text5");
}
}
public class SelectionBackgroundConverter : IValueConverter
{
public object Convert(object value, Type targetType,
object parameter, CultureInfo culture)
{
if (value != null)
{
SolidColorBrush brush = (SolidColorBrush)value;
Color newCol = brush.Color;
newCol.R -= 10;
newCol.G -= 10;
newCol.B -= 10;
BrushConverter conv = new BrushConverter();
Brush newBrush = (Brush)conv.ConvertTo(newCol, typeof(Brush));
return newBrush;
}
return Brushes.Transparent;
}
public object ConvertBack(object value, Type targetType,
object parameter, CultureInfo culture)
{
//never called
return null;
}
}
}
问题是，该转换器不会被调用...
有谁知道如何选择之前设置所选行有点暗比它的背景是什么？
The Problem is that the Converter never gets called... Does anyone know how to set the Background of the selected Row a bit darker than it was before selecting it?
任何帮助AP preciated！
Any help is appreciated!
更新
它看起来像它的工作但遗憾的是没有完全。
我已经纠正了该转换器看起来像这样：
It looks like its working but unfortunately not completely. I've corrected the Converter to look like this:
public class SelectionBackgroundConverter : IValueConverter
{
public object Convert(object value, Type targetType,
object parameter, CultureInfo culture)
{
if (value != null)
{
SolidColorBrush brush = (SolidColorBrush)value;
Color newCol = brush.Color;
newCol.R -= 10;
newCol.G -= 10;
newCol.B -= 10;
return new SolidColorBrush(newCol);
}
return Brushes.Transparent;
}
public object ConvertBack(object value, Type targetType,
object parameter, CultureInfo culture)
{
// we don't intend this to ever be called
return null;
}
现在的问题是，只有转换器被调用一次。我的意思是，如果我启动程序，然后单击任一行的转换被调用。如果我再点击进入另一行，DataGrid中或控制转换器不会被调用。
Now the problem is that the Converter only gets called once. I mean if I start the Program and click on any Row the Converter gets called. If I then click into another Row, DataGrid or Control the Converter doesn't get called.
任何想法如何解决这一问题？
Any Idea how to fix this?
推荐答案
现在的问题是在这个绑定：
The problem is in this binding:
Color="{Binding Background, Converter={StaticResource SelectionBackgroundConverter}}"
有没有来源和背景属性将不会在目前的情况下存在。它改成这样：
There is no Source, and the Background property won't exist in the current context. Change it to this:
Color="{Binding Source={x:Static SystemColors.HighlightBrush}, Converter={StaticResource SelectionBackgroundConverter}}"
和您的转换器将被调用。你在你的转换器有错误，虽然，但应该让你开始。也可以考虑：
And your converter will be called. You have bugs in your converter though, but that should get you started. Also consider:
- 冻结刷
- 缓存刷（如果你这样做了很多在您的应用程序）
这篇关于如何使用一个转换器设置SystemColors.HighlightBrushKey在WPF的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
