[英]How and Where to Create StaticResource Key for a Converter within the Simple XAML Window?
我有一個簡單的WPF XAML窗口,我需要在下面的XAML中創建一個StaticResource密鑰。
XAML源代碼是
<Window x:Class="WpfApplication1.Trigger"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:super="clr-namespace:WpfApplication1"
Title="Trigger" Height="300" Width="300">
<Grid>
<Border x:Name="m_Border" Width="100" Height="30" HorizontalAlignment="Center" VerticalAlignment="Top" Background="#FFF2FFC6" Margin="0,20,0,0">
<Button x:Name="btn" Content="iApp" HorizontalAlignment="Center" VerticalAlignment="Center" Width="75" Visibility="{Binding IsMouseOver,ElementName=m_Border, Converter={StaticResource BooleanToVisibilityConverterKey}, ConverterParameter=Normal}"/>
</Border>
</Grid>
</Window>
我的轉換器C#源代碼:
using System;
using System.Collections.Generic;
using System.Globalization;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Data;
namespace WpfApplication1
{
public enum BooleanToVisibilityConverterType
{
Normal = 1,
Reverse = 2
}
public class BooleanToVisibilityConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
var targertValue = false;
if (value == null)
{
throw new Exception("BooleanToVisibilityConverter - Convert Error");
}
else if (!Boolean.TryParse(value.ToString(), out targertValue))
{
throw new Exception("BooleanToVisibilityConverter - Convert Error");
}
else
{
var parameterValue = BooleanToVisibilityConverterType.Normal;
if (parameter != null)
{
Enum.TryParse<BooleanToVisibilityConverterType>(parameter.ToString(), out parameterValue);
}
if (parameterValue == BooleanToVisibilityConverterType.Reverse)
{
return targertValue ? Visibility.Collapsed : Visibility.Visible;
}
else
{
return targertValue ? Visibility.Visible : Visibility.Collapsed;
}
}
}
public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
{
var targetValue = Visibility.Collapsed;
if (value == null)
{
throw new Exception("BooleanToVisibilityConverter - ConvertBack Error");
}
else if (!Enum.TryParse<Visibility>(value.ToString(), out targetValue))
{
throw new Exception("BooleanToVisibilityConverter - ConvertBack Error");
}
else
{
var parameterValue = BooleanToVisibilityConverterType.Normal;
if (parameter != null)
{
Enum.TryParse<BooleanToVisibilityConverterType>(parameter.ToString(), out parameterValue);
}
if (parameterValue == BooleanToVisibilityConverterType.Reverse)
{
return targetValue == Visibility.Visible ? false : true;
}
else
{
return targetValue == Visibility.Visible ? true : false;
}
}
}
}
}
我需要一個名為BooleanToVisibilityConverterKey的轉換器鍵,用於Converter BooleanToVisibilityConverter
您通常將它放入周圍對象的Resources
屬性中,在本例中為Window
:
<Window x:Class="WpfApplication1.Trigger"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:super="clr-namespace:WpfApplication1"
Title="Trigger" Height="300" Width="300">
<Window.Resources>
<super:BooleanToVisibilityConverter x:Key="BooleanToVisibilityConverterKey"/>
</Window.Resources>
<Grid>
...
有些事情需要注意:
SystemColors
類中的各種屬性)。 您可以在Window.Resources
元素中定義Converter
。
<Window ...
>
<Window.Resources>
<super:BooleanToVisibilityConverter x:Key="BooleanToVisibilityConverterKey"/>
</Window.Resources>
...
將轉換器設為全局可能是個更好的主意。 這將使您不必在每個新Window
定義轉換器。 這也意味着您的轉換器僅實例化一次 ,因此略微提高了性能。
要實現此目的,請在App.xaml
定義轉換器。
<Application ...
xmlns:super="clr-namespace:WpfApplication1">
<Application.Resources>
<super:BooleanToVisibilityConverter x:Key="BooleanToVisibilityConverterKey"/>
</Application.Resources>
</Application>
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