我有一个问题导致标签在其内容没有变化但其格式有效时会刷新。 ContentStringFormat属性绑定到viewmodel并且通知属性更改,但标签没有更新,请在代码中找到最小的复制示例以及准备编译/运行的项目来演示问题。< / p>
下载项目:https://www.dropbox.com/s/rjs1lot09uc2lgj/WPFFormatBindingRefresh.zip?dl=0
XAML:
<StackPanel>
<Label Content="{Binding FirstLabelContent}"></Label>
<Label Content="{Binding SecondLabelContent}" ContentStringFormat="{Binding SecondLabelFormatContent}"></Label>
<Button Click="Button_Click">Add "test" to all bound elements</Button>
</StackPanel>
代码背后:
public event PropertyChangedEventHandler PropertyChanged = (a,b)=> { }; // empty handler avoids checking for null when raising
public string FirstLabelContent { get; set; } = "First Label";
public string SecondLabelContent { get; set; } = "Second";
public string SecondLabelFormatContent { get; set; } = "{0} Label";
void PropertyChange(string PropertyName)
{
PropertyChanged(this, new PropertyChangedEventArgs(PropertyName));
}
private void Button_Click(object sender, RoutedEventArgs e)
{
FirstLabelContent += " TEST";
SecondLabelFormatContent += " TEST";
PropertyChange("FirstLabelContent"); // First label correctly updates
PropertyChange("SecondLabelFormatContent"); // Second label doesn't update, expected behavior is changing the format string should cause an update
}
答案 0 :(得分:1)
Label
不支持通过绑定刷新ContentStringFormat
。
你可以使用这样的多转换器:
public class MultiConverter2 : IMultiValueConverter
{
public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
{
string SecondLabelContent = values[0] as string;
string SecondLabelFormatContent = values[1] as string;
return string.Format(SecondLabelFormatContent, SecondLabelContent);
}
public object[] ConvertBack(object value, Type[] targetTypes, object parameter, CultureInfo culture)
{
throw new NotSupportedException();
}
}
<强> XAML:强>
<StackPanel>
<StackPanel.Resources>
<local:MultiConverter2 x:Key="conv" />
</StackPanel.Resources>
<Label Content="{Binding FirstLabelContent}"></Label>
<Label>
<Label.Content>
<MultiBinding Converter="{StaticResource conv}">
<Binding Path="SecondLabelContent" />
<Binding Path="SecondLabelFormatContent" />
</MultiBinding>
</Label.Content>
</Label>
<Button Click="Button_Click">Add "test" to all bound elements</Button>
</StackPanel>