【发布时间】：2018-11-08 16:14:05
【问题描述】：
我有一个UserControl (FahrtControl.xaml) 和一个ListView。这个UserControl 绑定到我的MainWindow.xaml 中的ItemsControl。 MainWindow 有自己的 ViewModel，FahrtControl 有自己的 ViewModel。我现在想将Listview 项目的背景绑定到FahrtControl 的ViewModel 中的Brush 属性。
以下是我的代码的相关部分：
MainWindow.xaml：
<Window x:Class="WpfFrontend.Forms.Main.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:WpfFrontend.Forms.Main"
xmlns:fahrtControl="clr-namespace:WpfFrontend.Controls.FahrtControl"
mc:Ignorable="d">
<Window.DataContext>
<local:MainViewModel />
</Window.DataContext>
<Window.Resources>
<DataTemplate DataType="{x:Type fahrtControl:FahrtControlViewModel}">
<fahrtControl:FahrtControl />
</DataTemplate>
</Window.Resources>
<ItemsControl ItemsSource="{Binding Fahrten, UpdateSourceTrigger=PropertyChanged}" />
MainViewModel.cs：
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Linq;
using System.Runtime.CompilerServices;
using System.Windows.Controls;
using System.Windows.Media;
using Backend;
using DatabaseCommunication;
using WpfFrontend.Annotations;
using WpfFrontend.Controls.FahrtControl;
namespace WpfFrontend.Forms.Main
{
public class MainViewModel : INotifyPropertyChanged
{
public MainViewModel ()
{
SyncFahrten ();
}
private void SyncFahrten ()
{
var fahrtenPromise =
MainUtility.GetFahrtenToRangeAsync (GlobalProperties.Start, GlobalProperties.Start.AddDays (6));
fahrtenPromise.Task.GetAwaiter ().OnCompleted (() =>
{
AddFahrten (fahrtenPromise.Task.Result);
});
}
private void AddFahrten (List <ExtendedFahrt> fahrten)
{
foreach (var fahrtControlViewModel in
fahrten.Select (fahrt =>
{
return new FahrtControlViewModel (
Brushes.Red, Brushes.Red, Brushes.White,
fahrt.Ort,
new ObservableCollection <string>
{
fahrt.Bemerkung
}, new ObservableCollection <KundeDisplay> (fahrt.Kunden));
}))
Fahrten.Add (fahrtControlViewModel);
OnPropertyChanged ("");
}
private ObservableCollection <FahrtControlViewModel> _fahrten =
new ObservableCollection <FahrtControlViewModel> ();
public ObservableCollection <FahrtControlViewModel> Fahrten
{
get => _fahrten;
set
{
if (Equals (value, _fahrten))
return;
_fahrten = value;
OnPropertyChanged ();
}
}
public event PropertyChangedEventHandler PropertyChanged;
[NotifyPropertyChangedInvocator]
protected virtual void OnPropertyChanged ([CallerMemberName] string propertyName = null) =>
PropertyChanged?.Invoke (this, new PropertyChangedEventArgs (propertyName));
}
}
FahrtControl.xaml：
<UserControl x:Class="WpfFrontend.Controls.FahrtControl.FahrtControl"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:local="clr-namespace:WpfFrontend.Controls.FahrtControl"
mc:Ignorable="d"
d:DesignHeight="300" d:DesignWidth="300">
<UserControl.Resources>
<Style x:Key="HeaderStyle" TargetType="{x:Type GridViewColumnHeader}">
<Setter Property="Visibility" Value="Collapsed" />
</Style>
</UserControl.Resources>
<ListView ItemsSource="{Binding Kunden}"
Background="{Binding KundenBrush, UpdateSourceTrigger=PropertyChanged}">
<ListView.ItemContainerStyle>
<Style TargetType="ListViewItem">
<Setter Property="Background" Value="{Binding DataContext.KundenBrush}" />
</Style>
</ListView.ItemContainerStyle>
<ListView.View>
<GridView ColumnHeaderContainerStyle="{StaticResource HeaderStyle}">
<GridViewColumn DisplayMemberBinding="{Binding Name}" Header="Name" />
</GridView>
</ListView.View>
</ListView>
</UserControl>
FahrtControlViewModel.cs：
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Runtime.CompilerServices;
using System.Windows.Media;
using Backend;
using WpfFrontend.Annotations;
using WpfFrontend.Misc;
namespace WpfFrontend.Controls.FahrtControl
{
public class FahrtControlViewModel : INotifyPropertyChanged
{
private Brush _kundenBrush = Brushes.Red;
private ObservableCollection <KundeDisplay> _kunden;
/// <inheritdoc />
public FahrtControlViewModel (
Brush kundenBrush,
ObservableCollection <KundeDisplay> kunden)
{
Kunden = kunden;
KundenBrush = kundenBrush;
}
public Brush KundenBrush
{
get => _kundenBrush;
set
{
if (value.Equals (_kundenBrush))
return;
_kundenBrush = value;
KundenDark = _kundenBrush.IsDark ();
OnPropertyChanged ();
}
}
public ObservableCollection <KundeDisplay> Kunden
{
get => _kunden;
set
{
if (Equals (value, _kunden))
return;
_kunden = value;
OnPropertyChanged ();
}
}
public event PropertyChangedEventHandler PropertyChanged;
[NotifyPropertyChangedInvocator]
protected virtual void OnPropertyChanged ([CallerMemberName] string propertyName = null) =>
PropertyChanged?.Invoke (this, new PropertyChangedEventArgs (propertyName));
}
}
我已经尝试过以下方法：
- How i change ListView Item Background Color according to listview item HarfNotu value in wpf
- https://social.msdn.microsoft.com/Forums/vstudio/en-US/b25973bb-9e9c-4a99-8234-39a042e0a478/apply-styles-dynamically-to-buttons-in-xaml?forum=wpf
- How do I set the background color of a listview item in WPF using databinding?
- https://msdn.microsoft.com/en-us/library/system.windows.controls.contentcontrol.contenttemplateselector%28v=vs.110%29.aspx
- https://social.msdn.microsoft.com/Forums/vstudio/en-US/4df9f644-9bfa-4913-acc6-0bce711b70ec/setting-wpf-listview-background-when-disabled-and-empty?forum=wpf
- Binding the value of a Setter Property in WPF
- WPF Error 40 BindingExpression path error: property not found on 'object'
- How to set background of listview?
如果我不得不猜测与该主题稍微相关的所有其他建议。我在这里做错了什么？这与我在 ItemsControl 中使用 UserControl 的事实有关吗？其他属性绑定，没有被样式标签包围，在我的UserControl 中工作，所以它必须与样式标签有关，不是吗？
【问题讨论】：
-
在绑定中使用 PresentationTraceSources.TraceLevel=High 来调试它。您的 KundenBrush 设置正确吗？然后使用 UI 调试工具，探索 ListViewItems 是否设置了背景。