我有一个标准(WPF工具包)数据网格。一些列(明确定义)必须以百分比显示。如果值低于0,则某些列必须以红色显示。(两组列不相同)。我尝试分别使用StringFormat
和Style
来实现这些要求。我的XAML:
<Window xmlns:local="clr-namespace:myNamespace"
xmlns:tk="clr-namespace:Microsoft.Windows.Controls;assembly=WPFToolkit">
<Window.Resources>
<local:ValueConverter x:Key="valueToForeground" />
<Style TargetType="{x:Type tk:DataGridCell}">
<Setter Property="Foreground"
Value="{Binding RelativeSource={RelativeSource Self}, Path=Content.Text, Converter={StaticResource valueToForeground}}" />
</Style>
</Window.Resources>
<Grid>
<tk:DataGrid AutoGenerateColumns="False"
ItemsSource="{Binding Path=myClass/myProperty}">
<tk:DataGrid.Columns>
<tk:DataGridTextColumn Header="A"
Binding="{Binding colA}" />
<tk:DataGridTextColumn Header="B"
Binding="{Binding colB, StringFormat=\{0:P\}}" />
<tk:DataGridTextColumn Header="C"
Binding="{Binding colC, StringFormat=\{0:P\}}" />
<tk:DataGridTextColumn Header="D"
Binding="{Binding colD, StringFormat=\{0:P\}}" />
</tk:DataGrid.Columns>
</tk:DataGrid>
</Grid>
</Window>
相关的转换器:
namespace myNamespace
{
public class ValueConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
SolidColorBrush brush = new SolidColorBrush(Colors.Black);
Double doubleValue = 0.0;
if (value != null)
{
if (Double.TryParse(value.ToString(), out doubleValue))
{
if (doubleValue < 0)
brush = new SolidColorBrush(Colors.Red);
}
}
return brush;
}
public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
throw new NotImplementedException();
}
}
}
我认为这一切都非常标准,但问题是转换器在经过Text
后得到StringFormat
值,此时很难正确解析它(因为实际上) ,并非所有列都具有相同的格式)。如果我取出StringFormats
,转换器工作正常,文本显示为红色。我错过了一些明显的东西吗有一种简单的方法可以解决这个问题吗?我现在唯一能想到的就是将格式转移到另一个转换器中,我不相信它会起作用。
答案 0 :(得分:6)
我们遇到类似情况,我们需要Path
的不同Binding
属性,但每个CellStyle
需要类似的DataGridColumn
。我们使用自定义MarkupExtension
解决了这个问题。在你的情况下,它看起来像这样
<tk:DataGrid AutoGenerateColumns="False"
ItemsSource="{Binding MyItems}">
<tk:DataGrid.Columns>
<tk:DataGridTextColumn Header="A"
Binding="{Binding colA}" />
<tk:DataGridTextColumn Header="B"
Binding="{Binding colB, StringFormat=\{0:P\}}"
CellStyle="{markup:ForegroundCellStyle PropertyName=colB}"/>
<tk:DataGridTextColumn Header="C"
Binding="{Binding colC, StringFormat=\{0:P\}}"
CellStyle="{markup:ForegroundCellStyle PropertyName=colC}"/>
<tk:DataGridTextColumn Header="D"
Binding="{Binding colD, StringFormat=\{0:P\}}"
CellStyle="{markup:ForegroundCellStyle PropertyName=colD}"/>
</tk:DataGrid.Columns>
</tk:DataGrid>
然后ForegroundCellStyleExtension
为Style
创建DataGridCell
,具体取决于PropertyName
ForegroundCellStyleExtension
public class ForegroundCellStyleExtension : MarkupExtension
{
public ForegroundCellStyleExtension() { }
public ForegroundCellStyleExtension(string propertyName)
{
PropertyName = propertyName;
}
public string PropertyName
{
get;
set;
}
public override object ProvideValue(IServiceProvider serviceProvider)
{
IProvideValueTarget service = (IProvideValueTarget)serviceProvider.GetService(typeof(IProvideValueTarget));
DependencyObject targetObject = service.TargetObject as DependencyObject;
if (targetObject == null)
{
return null;
}
Binding foregroundBinding = new Binding
{
Path = new PropertyPath(PropertyName),
Converter = new ValueConverter()
};
Style foregroundCellStyle = new Style(typeof(DataGridCell));
foregroundCellStyle.Setters.Add(new Setter(DataGridCell.ForegroundProperty, foregroundBinding));
return foregroundCellStyle;
}
}
此外,如果您还想使用其他Setters
等,则可以将其他参数包含在MarkupExtension
中。
<Window.Resources>
<Style x:Key="dataGridCellStyle" TargetType="{x:Type tk:DataGridCell}">
<Setter Property="Background" Value="Blue"/>
</Style>
</Window.Resources>
<!-- ... -->
<tk:DataGridTextColumn Header="B"
Binding="{Binding colB, StringFormat=\{0:P\}}"
CellStyle="{markup:ForegroundCellStyle colB, {StaticResource dataGridCellStyle}}"/>
然后ForegroundCellStyleExtension
会将第二个参数用作BasedOn
DataGridCell
的{{1}}
Style
的 ForegroundCellStyleExtension
BasedOn
答案 1 :(得分:2)
为每列指定单元格样式,如下所示:
<DataGridTextColumn Header="ColA" Binding="{Binding colA, StringFormat=\{0:P\}}">
<DataGridTextColumn.CellStyle>
<Style TargetType="DataGridCell">
<Setter Property="Foreground"
Value="{Binding colA, Converter={StaticResource valueToForeground}}" />
</Style>
</DataGridTextColumn.CellStyle>
</DataGridTextColumn>
<DataGridTextColumn Header="ColB" Binding="{Binding colB, StringFormat=\{0:P\}}">
<DataGridTextColumn.CellStyle>
<Style TargetType="DataGridCell">
<Setter Property="Foreground"
Value="{Binding colB, Converter={StaticResource valueToForeground}}" />
</Style>
</DataGridTextColumn.CellStyle>
</DataGridTextColumn>
...
并修改您的转换器
public class ValueConverter : IValueConverter
{
public object Convert(
object value, Type targetType, object parameter, CultureInfo culture)
{
return ((double) value < 0) ? Brushes.Red : Brushes.Black;
}
public object ConvertBack(
object value, Type targetType, object parameter, CultureInfo culture)
{
return Binding.DoNothing;
}
}
答案 2 :(得分:1)
我想到的最简单的方法是将您的完整项目而不是item / content.text仅绑定到您的转换器。然后,您将能够对您的单元格执行您需要担心的项目和参数值。
在你的手柄样式中:
<Setter Property="Foreground"
Value="{Binding Converter={StaticResource valueToForeground}}" />
并在您的转换器代码中:
public object Convert(object value, Type targetType,
object parameter, System.Globalization.CultureInfo culture)
{
SolidColorBrush brush = new SolidColorBrush(Colors.Black);
Double doubleValue = 0.0;
if (value != null)
{
mydatatype data = value as mydatatype;
//your logic goes here and also can play here with your dataitem.
if (Double.TryParse(data.CollD.ToString(), out doubleValue))
{
if (doubleValue < 0)
brush = new SolidColorBrush(Colors.Red);
}
}
return brush;
}